Improvements in or relating to pressure reducing valves

Abstract

A pressure relief valve having an inlet port and an outlet port is disclosed to maintain pressure from the outlet until a set pressure is reached at the inlet. The valve has a valve member between the inlet port and the outlet port, the valve member being movable between an open position allowing fluid flow between the ports and a closed position preventing fluid flow. The inlet pressure acts on the valve member to increase its closing force. A movable sensing mandrel in fluid communication with an inlet pressure and a reference pressure is provided, the sensing mandrel having a first position and a second position. An increased pressure difference between the inlet pressure and a reference towards the set pressure moves the sensing mandrel to ultimately act on the valve member, thereby moving the valve member away from its sealing position and thus providing an opening for fluid flow from the inlet to the outlet.

Description

Technical Field

[0001] The present invention relates to valves.

[0002] Specifically, although not exclusively, the present invention relates to pressure reducing valves. Background Art

[0003] A pressure reducing valve (PRV) is used to discharge pressure from a process when the inlet pressure exceeds a desired limit. For example, this can be for safety, among other things, or to keep a process within certain operating bounds.

[0004] Typical pressure reducing valves use an energized valve member to maintain the pressure at the inlet. When the pressure at the inlet exceeds the force holding the valve member closed, the valve member opens to a port, releases, vents, or otherwise allows the excess pressure to escape, typically through an outlet. Energizing the valve member can be achieved by a spring acting downwardly on the valve member in a conventional manner, or by other means, such as pilot operation, mass loading, or gas loading (on the back side of a piston acting on the valve member).

[0005] All of these existing systems have drawbacks. Conventional safety valves have a high seating force of the valve, which decreases as the pressure increases until the pressure overwhelms the seat spring force. This means that when the valve is in a warehouse or installed in a non-pressurized manner, the valve is constantly subjected to high pressure. This requires that the seat / seal system must be designed to withstand the full spring preload force. This is either achieved by a large seating surface on a metal / metal seal, which results in poor sealing performance when approaching the set pressure, leading to low pressure pre-ignition / warning / leakage. Alternatively, a soft seal can sometimes be used in combination with a hard stop in less demanding usage cases to maintain a higher force of the spring and prevent over-compression of the soft seal. However, in some cases, such as for high temperature steam use, soft seal inserts are generally not recommended. In the case of a conventional pressure reducing valve with a hard stop and soft seating, there is a maximum compression achievable on the soft seal (due to the hard stop). Polymer seal materials can (especially when exposed to higher temperatures) undergo compression deformation - change shape - thereby reducing the seating force transmitted through the polymer component. Over time, this can lead to a reduced or variable true opening pressure or set pressure - which is undesirable because the set pressure must be controlled within strict parameters. A pressure reducing valve that cannot be tested at its set pressure must be reset or taken out of service for repair or replacement.

[0006] Traditional PRVs also have additional drawbacks, as they are costly at large sizes, with large nozzle diameters and pressures resulting in large forces on the spring and other hardware. They have low seat tightness and pre-ignition pressure (the pressure at which the valve starts to leak / almost open is typically about 90% of the set pressure). Due to the lack of pressure balance, they also have poor performance in applications with variable or high backpressure. This adversely affects their performance, and they may lose accuracy as the outlet pressure directly affects the pressure during valve operation. To operate in a variable backpressure environment, bellows or other balancing methods are required, which can be mechanically sensitive and have relatively low backpressure tolerance compared to pilot-operated relief valves; adding balancing bellows is expensive. Alternatively, a piston seal between the process fluid volume and the atmosphere (ambient) can be used to balance the spool to eliminate this effect. The disadvantage of the piston seal compared to the bellows is that the guide seal and spool seal are typically elastomers or plastics, so temperature and chemical compatibility with the working fluid need to be considered, and the same high spring force is still required for high-pressure applications, resulting in a high seating load.

[0007] In addition, in direct-acting PRVs that use a soft (also called "elastic") seating element without a hard stop, the constant force acting on the soft seating element can reduce the valve's lifespan due to the compression set of the soft material - resulting in premature leakage or variable opening or set pressure.

[0008] For many applications, traditional valves also require large, high-force springs. For high-flow or high-pressure applications, large springs must be used because in traditional pressure reducing valves, the pressure sensing area is equal to the nozzle diameter, thus determining the maximum possible flow rate.

[0009] As the pressure increases, the reduced seating force results in low pre-ignition (also called warning or leakage) below the set pressure, which is harmful to the efficiency of many processing systems.

[0010] Traditional PRVs can be affected by high or variable discharge pressures, as this can significantly change the valve's set point, or render traditional valves unsuitable for certain applications, or require traditional valves with additional balancing features, with additional cost and complexity.

[0011] Although balanced piston PRV valves may be suitable in some applications, the piston seal must have the same diameter as the seat and must have high integrity as it seals the process fluid from the environment. High anti-leakage / emission regulating compliant valve stem packings such as high-temperature graphite or braided PTFE, especially those with a large diameter, tend to result in high friction - too high to provide a sufficiently accurate set point for critical safety systems.

[0012] The balanced bellows PRV provides a substantially frictionless seal and can isolate the valve from the effects of backpressure on the valve. However, in order for the bellows PRV to provide the desired balancing effect, the diameter of the bellows must be large enough to match the nozzle pressure area and the bellows. In order for a relatively short, large-diameter, and pressure-resistant bellows to be able to move a considerable distance, the bellows must be made of multiple very thin and fragile layers. The design compromises exhibited in these bellows typically limit the backpressure they can handle - generally, the backpressure must be limited to 20% or 30% of the valve set pressure.

[0013] Due to the sliding soft seal, the pilot-operated pressure reducing valve (PORV or POPRV) has limited high-temperature applications. Due to the complexity and small diameter of the pipeline and the pilot valve, they cannot be used in hygienic clean-in-place (CIP) applications either. Due to the small flow paths in the pilot valve and the pipeline, the PORV may not be well-suited for highly viscous or process media containing a high content of particles. In smaller sizes, the PORV is usually more expensive than traditional valves, and they also often use non-standard ports (such as API 526). Compared with traditional valves, the PORV is generally considered complex and specialized. In some cases, their multi-stage operation can result in a slower response than direct-acting valves. They require a separate pilot control valve, small-diameter pipelines, and sensing valves - driving up costs and assembly complexity.

[0014] In this specification, where reference has been made to patent specifications, other external documents, or other information sources, this is usually to provide context for discussing the features of the invention. Unless otherwise expressly stated, references to such external documents should not be construed as an admission that such documents or such information sources are prior art within any scope of rights or form part of the common general knowledge in the art.

[0015] An object of the present invention is to provide an improved pressure reducing valve, or to overcome the above disadvantages or solve the above needs, or at least to provide a useful alternative for the public. Summary of the Invention

[0016] In a first aspect, the present invention resides in a pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including,

[0017] a valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior,

[0018] A valve member operatively positioned within the valve body, the valve member having on its first side a first pressure surface in fluid communication with the inlet fluid and a second pressure surface on its second side, the second pressure surface being opposite the first surface and also in fluid communication with the inlet fluid, a first sealing surface on the first side to seal the inlet and the outlet in isolation,

[0019] A first biasing force that urges the valve member to a first valve position, whereby the first biasing force seals the inlet and the outlet open,

[0020] A sensing spindle in fluid communication with the inlet fluid, the sensing spindle having a third pressure surface in fluid communication with the inlet fluid, a second biasing force that urges the sensing spindle to a first spindle position against the inlet fluid pressure acting on the third pressure surface, the second biasing force not being added to the first biasing force,

[0021] Such that in use, the inlet fluid acting on the second pressure surface adds to the first biasing force in sealing the first sealing surface to the inlet, and

[0022] When the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position, the second spindle position breaking the seal between the first sealing surface and the inlet, and the inlet fluid can flow out to the outlet.

[0023] Preferably, when under pressure but below the set pressure, the inlet fluid acting on the second pressure surface generates a force greater than the first biasing force in sealing the first sealing surface to the inlet.

[0024] In a first aspect, the present invention resides in a pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including,

[0025] A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior,

[0026] A valve cap removably engaged to the valve body between the first port and the second port so as to further define a conduit therebetween,

[0027] A valve member having an annular skirt within the conduit, the annular skirt having an outer periphery, the valve body at least partially surrounding the outer periphery to define an annular chamber, and the annular skirt having an inner periphery that defines an inner chamber, the valve member having a closed position that prevents fluid flow and an open position that allows fluid flow,

[0028] The annular skirt slides and sealingly engages with the valve cap at the open position and the closed position and between the open position and the closed position at a first sealing diameter or perimeter.

[0029] The outer base of the valve member, when in the closed position, sealingly abuts the valve body at a second sealing diameter or perimeter.

[0030] The first sealing diameter or perimeter is greater than the second sealing diameter or perimeter. A first pressure region is defined between the first sealing diameter or perimeter and the second sealing diameter or perimeter. The first pressure region provides a bias towards the closed position when receiving fluid into the inner chamber under pressure.

[0031] When in the open position, an opening is defined between the valve body and the valve member to allow fluid to flow between the first ports through the opening to the second ports.

[0032] A sensing spindle that slides and sealingly engages with the valve cap at a third sealing diameter or perimeter (D3). The third sealing diameter or perimeter (D3) defines a second pressure region that provides a bias towards the open position when receiving pressurized fluid.

[0033] Such that in use, the inlet fluid acting on the second pressure surface subtracts from the first biasing force during the process of sealing the first sealing surface to the inlet. And when the inlet pressure exceeds the set pressure, the sensing spindle moves to or towards a second spindle position that breaks the seal at the first sealing diameter, and the inlet fluid can leave to the outlet.

[0034] Preferably, the valve member is biased closed by a first bias.

[0035] Preferably, in addition to the first bias, the first pressure region also provides a bias from the pressurized fluid.

[0036] Preferably, the third sealing diameter is less than the second sealing diameter.

[0037] Preferably, there is a second bias acting on the sensing spindle that opposes the inlet fluid acting on the second pressure surface.

[0038] In another aspect, the present invention resides in a pressure reducing valve having an inlet port and an outlet port, the pressure reducing valve comprising or including,

[0039] A valve member located between the inlet port and the outlet port, the valve member being movable between an open position allowing fluid to flow between the ports and a closed position preventing fluid flow.

[0040] The valve member is in fluid communication with the inlet port and the outlet port,

[0041] A movable sensing spindle in fluid communication with the inlet pressure and a reference pressure,

[0042] The sensing spindle has a first position and a second position, and the sensing spindle acts on the valve member towards the second position to move the valve member away from its sealing position,

[0043] The valve member being in any position other than its sealing position will result in a fluid connection between the inlet and the outlet.

[0044] In another aspect, the present invention resides in a pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including,

[0045] A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior,

[0046] A valve member operably positioned within the valve body, the valve member having a first pressure surface on its first side that is in fluid communication with the inlet fluid, and a second pressure surface on its second side, the second pressure surface being opposite the first surface and also in fluid communication with the inlet fluid, the difference between the first pressure surface and the second pressure surface defining a first pressure area on which the inlet pressure and the outlet pressure act, and a first sealing surface on the first side to seal the inlet from the outlet in isolation,

[0047] A first biasing force that urges the valve member to a first valve position, whereby the first biasing force seals the inlet from the outlet,

[0048] A sensing spindle in fluid communication with the inlet fluid, the sensing spindle having a second pressure area in fluid communication with the inlet fluid, a second biasing force that resists the inlet fluid pressure acting on the second pressure area to urge the sensing spindle to a first spindle position, the second biasing force not being added to the first biasing force,

[0049] Such that in use, the pressure difference between the inlet and outlet fluids acting on the first pressure area adds to the first biasing force when sealing the first sealing surface to the inlet, and

[0050] Wherein when the inlet pressure exceeds a set pressure, the sensing spindle is moved to or towards a second spindle position by the action of the inlet pressure on the second pressure region, thereby acting on the valve member to create a separation between the valve member and the sealing surface and enabling flow between the inlet and the outlet.

[0051] Preferably, when the sensing spindle acts on the valve member, the sensing spindle moves the valve member to or towards a second valve position.

[0052] In another aspect, the present invention resides in a pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow inlet fluid to flow from an inlet to an outlet, the pressure reducing valve comprising or including,

[0053] A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior,

[0054] A valve member operatively positioned within the valve body, the valve member having a first pressure region on which the inlet pressure and the outlet pressure act, and a first sealing surface located on the first side to seal off the inlet from the outlet,

[0055] A first biasing force that urges the valve member to a first valve position, whereby the first biasing force seals off the inlet from the outlet,

[0056] A sensing spindle in fluid communication with the inlet fluid, the sensing spindle having a second pressure region in fluid communication with the inlet fluid, and a second biasing force that resists the inlet fluid pressure acting on the second pressure region from urging the sensing spindle to a first spindle position, the second biasing force not adding to the first biasing force,

[0057] Such that in use, the pressure differential between the inlet and outlet fluids acting on the first pressure region adds to the first biasing force when sealing the first sealing surface to the inlet, and

[0058] Wherein when the inlet pressure exceeds a set pressure, the sensing spindle is moved to or towards a second spindle position by the action of the inlet pressure on the second pressure region, thereby acting on the valve member to create a separation between the valve member and the sealing surface and enabling flow between the inlet and the outlet.

[0059] Preferably, the valve member has a first pressure surface on its first side that is in fluid communication with the inlet fluid, and a second pressure surface on its second side opposite the first surface that is also in fluid communication with the inlet fluid, the difference between the first and second pressure surfaces defining the first pressure region.

[0060] In yet another aspect, the present invention resides in a pressure reducing valve that operates on an inlet pressurized fluid to prevent and permit the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including,

[0061] A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior,

[0062] A valve member operatively positioned within the valve body, the valve member having a first pressure region on which the inlet pressure and the outlet pressure act, a first sealing surface located on a first side of the valve member for sealing against an inlet sealing surface and sealingly isolating the inlet from the outlet,

[0063] A first biasing force that urges the valve member to a first valve position, whereby the first biasing force is capable of sealing the inlet and the outlet open,

[0064] A sensing spindle in fluid communication with the inlet, the sensing spindle having a second pressure region in fluid communication with the inlet fluid, a second biasing force that resists the inlet fluid pressure acting on the second pressure region to urge the sensing spindle to a first spindle position, the second biasing force not adding to the first biasing force,

[0065] such that in use, the pressure differential between the inlet and the outlet fluid acting on the first pressure region adds to the first biasing force to seal the inlet and the outlet off from each other, and

[0066] wherein in use when the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position via the action of the inlet pressure on the second pressure region, thereby acting on the valve member to create a separation between the first sealing surface and the inlet sealing surface and allowing fluid to flow between the inlet and the outlet.

[0067] Preferably, the valve member has a first pressure surface on its first side that is in fluid communication with the inlet fluid, and a second pressure surface on its second side opposite the first pressure surface that is also in fluid communication with the inlet fluid, the net difference between the first and second pressure surfaces defining the first pressure region on which the inlet pressure and the outlet pressure act.

[0068] Preferably, the pressure difference between the inlet and outlet fluids acting on the first pressure region generates a net pressure in addition to the first biasing force for sealing the valve member.

[0069] Preferably, a third pressure surface defining the second pressure region is provided on the sensing mandrel.

[0070] Preferably, the separation of the first sealing surface and the inlet sealing surface reduces the net force provided by the first pressure region such that the first sealing surface and the inlet sealing surface are further separated by the sensing mandrel to enable fluid to flow between the inlet and the outlet.

[0071] Preferably, the first and / or second biasing is adjustable.

[0072] Preferably, the first biasing is a spring or other elastic or similar biasing that can provide an initial force to hold the first sealing surface against the inlet sealing surface.

[0073] Preferably, the sensing mandrel is substantially received within the valve member.

[0074] Preferably, the area of the second pressure surface is greater than the area of the first pressure surface to increase the force for holding the valve member in a sealed state.

[0075] Preferably, the area ratio of the first pressure surface to the second pressure surface can be adjusted through the inlet to change the on-force for closing the valve member.

[0076] Preferably, an annular chamber in communication with the outlet fluid exists around the valve member.

[0077] Preferably, the second pressure region or the pressure surface of the mandrel is used to overcome the combined closing force of the first biasing and the resultant force of the first pressure region and the inlet pressure and outlet pressure acting thereon to move the valve member from the first valve position and open the seal of the valve member.

[0078] Preferably, the valve member is an annular member and the first sealing surface is close to the inlet.

[0079] Preferably, the first sealing surface is an annular surface.

[0080] Preferably, the inlet sealing surface is annular to cooperate with the first sealing surface.

[0081] Preferably, at least one fluid passage exists between the first pressure surface and the second pressure surface.

[0082] Preferably, the fluid passage is within the perimeter of the first sealing surface such that when the first sealing surface seals to the inlet sealing surface, there is no fluid communication to the outlet.

[0083] Preferably, the first biasing force is provided by a helical spring disposed around the outer surface of the valve member.

[0084] Preferably, the second biasing force is provided by a helical spring.

[0085] Preferably, there is a stop to hold the sensing spindle in the first spindle position against the second biasing force.

[0086] Preferably, the second biasing is adjustable in its force to partly allow adjustment of the set pressure.

[0087] Preferably, when the inlet fluid pressure increases but remains below the set pressure, the first pressure region increases the force holding the valve member sealed.

[0088] Preferably, the at least one fluid passage is located at the axial center of the valve member, and the sensing spindle passes through the at least one fluid passage towards the inlet.

[0089] Preferably, the sensing spindle and the valve member translate along a longitudinal axis from their respective first positions to their respective second positions.

[0090] Preferably, the annular member defining the valve member, the first sealing surface and the inlet sealing surface are concentric with the longitudinal axis.

[0091] Preferably, there is an additional fluid passage between the first pressure region and the second pressure region.

[0092] Preferably, when the sensing spindle moves from its first position to its second position or towards its second position, the cross-section of the sensing spindle located upstream of the valve member serves as a pawl to engage and open the valve member.

[0093] Preferably, the diameter of the cross-section is larger than the diameter of the fluid passage through which the sensing spindle passes, so that the sensing spindle can engage and move the valve member.

[0094] Preferably, the stop is also used to form the annular chamber and is sealed to the inner circumference of the annular chamber.

[0095] Preferably, the sensing spindle and the valve member are in separate sliding seals with the stop.

[0096] Preferably, the sensing spindle has a stop portion that engages with the stop to hold the sensing spindle in the first spindle position against the second biasing force.

[0097] Preferably, there is a guide skirt on the valve member that extends to or into the inlet and slidably engages with the inlet to guide the valve member when the valve member is sealed and unsealed.

[0098] Preferably, the guide skirt is in sliding sealing engagement with the inlet.

[0099] Preferably, the fluid passage is unsealed during a first movement of the valve member towards the second valve position, and the valve skirt or its second fluid passage is unsealed during a second further movement of the valve member towards the second valve position.

[0100] Preferably, the valve member is balanced with respect to the inlet pressure and the outlet pressure.

[0101] In another aspect, the present invention resides in a method of operating a pressure reducing valve to operate on an inlet pressurized fluid to prevent and permit flow of the inlet fluid from the inlet to the outlet, the method comprising or including,

[0102] Biasing a valve member to seal an opening from the inlet to the outlet, the valve member having a first pressure region upon which the inlet fluid pressure can act to increase the sealing force of the valve member on its seat, in addition to the valve member being biased to seal the inlet and the outlet.

[0103] Biasing a sensing spindle against the inlet fluid pressure acting on a second pressure region of the sensing spindle from the inlet, the biasing of the sensing spindle not increasing the biasing of the valve member, the biasing of the sensing spindle providing a set pressure at which the sensing spindle does not move, wherein,

[0104] Below the set pressure, the sensing spindle does not contact the valve member, the biasing of the valve member and the inlet pressure on the first pressure region maintain the valve element sealed, and the biasing of the sensing spindle maintains the sensing piston against a hard stop.

[0105] Near the set pressure, the valve member is more forcefully pressed into its seat by the action of the first pressure region.

[0106] Just below the set pressure, the sensing spindle, independent of the valve member, moves towards the currently stationary valve member and contacts the currently stationary valve member, but the inlet pressure is not sufficient to overcome the biasing of the valve member and the force on the first pressure region acting on the valve member.

[0107] Once the set pressure is reached, the inlet fluid pressure on the second pressure region (greater than the first pressure region) is now high enough to overcome the biasing of the valve member and the biasing of the sensing spindle, and the sensing spindle then moves the valve member to open the opening and permit fluid flow between the inlet and the outlet.

[0108] This provides a pressure reducing valve having a low initial sealing pressure, and the sealing pressure increases with the inlet fluid pressure to prevent the inlet fluid from flowing to the outlet until a set pressure is reached, at which point the opening is opened to allow fluid to flow from the inlet to the outlet.

[0109] In another aspect, the invention resides in a method of operating a pressure reducing valve to operate on an inlet pressurized fluid to prevent and allow inlet fluid to flow from the inlet to the outlet, the method comprising or including,

[0110] Biasing a valve member to seal an opening from the inlet to the outlet, the valve member having a first pressure region upon which the inlet fluid pressure can act to increase the sealing force of the valve member on its seat, in addition to the valve member being biased to seal the inlet and the outlet.

[0111] Biasing a sensing spindle against the inlet fluid pressure acting on a second pressure region of the sensing spindle from the inlet, the biasing of the sensing spindle not increasing the biasing of the valve member, the biasing of the sensing spindle providing a set pressure at which the sensing spindle does not move, wherein,

[0112] Below the set pressure, the sensing spindle does not contact the valve member, the biasing of the valve member and the inlet pressure on the first pressure region maintain the valve element sealed, and the biasing of the sensing spindle holds the sensing spindle against a hard stop.

[0113] Once the set pressure is reached, the inlet fluid pressure on the second pressure region (greater than the first pressure region) is now high enough to overcome the biasing of the valve member and the biasing of the sensing spindle, and the sensing spindle then moves the valve member to open the opening and allow fluid flow between the inlet and the outlet.

[0114] This provides a pressure reducing valve having a low initial sealing pressure, and the sealing pressure increases with the inlet fluid pressure to prevent the inlet fluid from flowing to the outlet until a set pressure is reached, at which point the opening is opened to allow fluid to flow from the inlet to the outlet.

[0115] Preferably, just below the set pressure, the sensing spindle independent of the valve member moves towards the currently stationary valve member and contacts the currently stationary valve member, but the inlet pressure is not sufficient to overcome the biasing of the valve member and the force on the first pressure region acting on the valve member.

[0116] Preferably, there is a first pressure surface in fluid communication with the inlet fluid on a first side of the valve member, and a second pressure surface also in fluid communication with the inlet fluid on a second side of the valve member opposite the first pressure surface, and the net difference between the first and second pressure surfaces defines the first pressure region on which the inlet pressure and the outlet pressure act.

[0117] Preferably, the pressure difference between the inlet and outlet fluids acting on the first pressure region generates a net pressure in addition to the first biasing force for sealing the valve member.

[0118] Preferably, a third pressure surface defining the second pressure region is provided on the sensing mandrel.

[0119] Preferably, the separation of the first sealing surface and the inlet sealing surface reduces the net force provided by the first pressure region, such that the first sealing surface and the inlet sealing surface are further separated by the sensing mandrel to enable fluid to flow between the inlet and the outlet.

[0120] Preferably, the first and / or second biasing is adjustable.

[0121] Preferably, the first biasing is a spring or other elastic or similar biasing that can provide an initial force to hold the first sealing surface against the inlet sealing surface.

[0122] Preferably, the sensing mandrel is substantially received within the valve member.

[0123] Preferably, the area of the second pressure surface is greater than the area of the first pressure surface to increase the force for holding the valve member in a sealed state.

[0124] Preferably, the area ratio of the first pressure surface to the second pressure surface can be adjusted through the inlet to change the energizing force for closing the valve member.

[0125] Preferably, an annular chamber in communication with the outlet fluid exists around the valve member.

[0126] Preferably, the second pressure region or the pressure surface of the mandrel is used to overcome the combined closing force of the first biasing and the resultant force of the first pressure region and the inlet pressure and outlet pressure acting thereon to move the valve member from the first valve position and open the seal of the valve member.

[0127] Preferably, the valve member is an annular member and the first sealing surface is adjacent to the inlet.

[0128] Preferably, the first sealing surface is an annular surface.

[0129] Preferably, the inlet sealing surface is annular to cooperate with the first sealing surface.

[0130] Preferably, at least one fluid passage exists between the first pressure surface and the second pressure surface.

[0131] Preferably, the fluid passage is within the perimeter of the first sealing surface such that there is no fluid communication to the outlet when the first sealing surface seals to the inlet sealing surface.

[0132] Preferably, the first biasing force is provided by a helical spring disposed around the outer surface of the valve member.

[0133] Preferably, the second biasing force is provided by a helical spring.

[0134] Preferably, there is a stop to hold the sensing spindle in the first spindle position against the second biasing force.

[0135] Preferably, the second biasing is adjustable in its force to partly allow adjustment of the set pressure.

[0136] Preferably, when the inlet fluid pressure increases but remains below the set pressure, the first pressure region increases the force holding the valve member sealed.

[0137] Preferably, the at least one fluid passage is located at the axial center of the valve member, and the sensing spindle passes through the at least one fluid passage towards the inlet.

[0138] Preferably, the sensing spindle and the valve member translate along the longitudinal axis from their respective first positions to their respective second positions.

[0139] Preferably, the annular member defining the valve member, the first sealing surface and the inlet sealing surface are concentric with the longitudinal axis.

[0140] Alternatively, the annular member defining the valve member, the first sealing surface and the inlet sealing surface are not concentric with the longitudinal axis as they seal on a flat surface.

[0141] Preferably, there is an additional fluid passage between the first pressure region and the second pressure region.

[0142] Preferably, when the sensing spindle moves from its first position to its second position or towards its second position, the cross-section of the sensing spindle located upstream of the valve member serves as a pawl to engage and open the valve member.

[0143] Preferably, the diameter of the cross-section is larger than the diameter of the fluid passage through which the sensing spindle passes, so that the sensing spindle can engage and move the valve member.

[0144] Preferably, the stop is also used to form the annular chamber and is sealed to the inner circumference of the annular chamber.

[0145] Preferably, the sensing spindle and the valve member are in separate sliding seals with the stop.

[0146] Preferably, the sensing spindle has a stop that engages with the stop to hold the sensing spindle in the first spindle position against the second biasing force.

[0147] Preferably, a guiding skirt is provided on the valve member, which extends to or into the inlet and is in sliding engagement with the inlet to guide the valve member when the valve member is sealing and unsealing.

[0148] Preferably, the guiding skirt is in sliding and sealing engagement with the inlet.

[0149] Preferably, the fluid passage is unsealed during a first movement of the valve member towards the second valve position, while the valve skirt or its second fluid passage is unsealed during a second further movement of the valve member towards the second valve position.

[0150] Preferably, the valve member is balanced with respect to the inlet pressure and the outlet pressure.

[0151] In another aspect, the present invention resides in a method of operating a pressure reducing valve to operate on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the method comprising or including,

[0152] providing a valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior,

[0153] providing a valve cap removably engaged to the valve body between the first port and the second port so as to further define a conduit therebetween,

[0154] providing a valve member having an annular skirt within the conduit, the annular skirt having an outer periphery, the valve body at least partially surrounding the outer periphery to define an annular chamber, and the annular skirt having an inner periphery defining an inner chamber, the valve member having a closed position preventing fluid flow and an open position allowing fluid flow,

[0155] the annular skirt is in sliding and sealing engagement with the valve cap at a first sealing diameter or periphery at the open position and the closed position and between the open position and the closed position,

[0156] providing an outer base of the valve member which seals against the valve body at a second sealing diameter or periphery when in the closed position,

[0157] the first sealing diameter or periphery is greater than the second sealing diameter or periphery, a first pressure region, the first pressure region being defined between the first sealing diameter or periphery and the second sealing diameter or periphery, the first pressure region providing a bias towards the closed position when receiving fluid into the inner chamber under pressure,

[0158] when in the open position, an opening is defined between the valve body and the valve member to allow fluid to flow between the first ports to the second port via the opening,

[0159] Provided is a sensing spindle that slidably and sealingly engages with the valve cap at a third sealing diameter or perimeter (D3), the third sealing diameter or perimeter (D3) defining a second pressure region that provides a bias toward the open position when receiving pressurized fluid.

[0160] Such that in use, the inlet fluid acting on the second pressure surface subtracts from the first biasing force during sealing of the first sealing surface to the inlet, and when the inlet pressure exceeds a set pressure, the sensing spindle moves to or toward a second spindle position that breaks the seal at the first sealing diameter and the inlet fluid can exit to the outlet.

[0161] In another aspect, the present invention resides in a method of operating a pressure reducing valve having an inlet port and an outlet port, the method comprising or including,

[0162] Providing a valve member located between the inlet port and the outlet port, the valve member being movable between an open position allowing fluid to flow between the ports and a closed position preventing fluid flow.

[0163] The valve member is in fluid communication with the inlet port and the outlet port.

[0164] Providing a movable sensing spindle in fluid communication with the inlet pressure and a reference pressure.

[0165] Allowing the sensing spindle to move between a first position and a second position, the sensing spindle acting on the valve member toward the second position to move the valve member away from its sealing position.

[0166] The valve member being in any position other than its sealing position will result in fluid connection between the inlet and the outlet.

[0167] In another aspect, the present invention resides in a pressure reducing valve as described in any one or more of the accompanying drawings herein.

[0168] In another aspect, the present invention resides in a method of operating a pressure reducing valve as described in any one or more of the accompanying drawings herein.

[0169] As used herein, the term “and / or” means “and” or “or”, or both.

[0170] As used herein, “(s)” following a noun means the plural and / or singular form of that noun.

[0171] As used in this specification, the term "comprising" means "consisting at least in part of". When interpreting statements in this specification that include this term, the features starting with this term in each statement are required to be present, and other features may also be present. Related terms such as "comprise" and "comprised" will be interpreted in the same manner.

[0172] The numerical ranges disclosed herein (e.g., 1 to 10) also include all rational numbers within the mentioned range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) and any range of rational numbers within the mentioned range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7).

[0173] The entire disclosures of all applications, patents, and publications (if any) cited above and below are incorporated herein by reference.

[0174] The present invention can also be broadly described as including the parts, elements, and features individually or jointly mentioned or indicated in the specification of this application, and any or all combinations of any two or more of said parts, elements, and features, and wherein specific integers are mentioned herein, and these specific integers have known equivalents in the field to which the present invention pertains, and these known equivalents are considered to be incorporated herein as if individually set forth.

[0175] Other aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0176] Preferred forms of the present invention will now be described with reference to the accompanying drawings, in which:

[0177] Figure 1 A side perspective view of a pressure reducing valve according to the present invention is shown,

[0178] Figure 2 is shown Figure 1 a front isometric view of the pressure reducing valve of, showing some internal components through the valve outlet,

[0179] Figure 3 is shown Figure 1 a bottom isometric view of the pressure reducing valve of, showing some internal components through the valve inlet,

[0180] Figure 4 is shown Figure 1 a side vertical section of the valve of,

[0181] Figure 5 is shown Figure 4 a close-up of the upper region of the section of,

[0182] Figure 6 Shows a Figure 4 close - up of the lower region of the cross - section of

[0183] Figure 7 Shows a Figure 1 isometric exploded view of the valve of

[0184] Figure 8 Shows a Figure 7 close - up of the upper region of the exploded view of

[0185] Figure 9 Shows a Figure 7 close - up of the lower region of the exploded view of

[0186] Figure 10 Shows a schematic diagram of the internal components and operation of a valve consistent with the present invention,

[0187] Figure 11 is a graph of the relationship between pressure and sensed piston displacement of the present invention compared with two prior - art pressure - reducing valves;

[0188] Figure 12 is a graph of the relationship between pressure and valve seating force of the present invention compared with two prior - art pressure - reducing valves;

[0189] Figure 13 Shows the interior of the lower valve, where the valve body has been removed before reaching the set release pressure,

[0190] Figure 14 Shows a Figure 13 view in which the valve has started to open due to reaching the set pressure,

[0191] Figure 15 Shows a Figure 13 view in which the valve is now fully or nearly fully open and releases the pressure as the set release pressure has been reached,

[0192] Figure 16 Shows a schematic cross - section of the pressure - reducing valve,

[0193] Figure 17 Shows another cross - section with a bellows - type seal,

[0194] Figure 18 Shows another variant of the present invention in a vertical cross - section along the main axis.

[0195] Figure 19 Shows a vertical cross - section of another variant of the present invention, which utilizes a flat sealing interface between the valve member and the valve body, and an enclosed first bias of the valve member, with the valve in the closed position,

[0196] Figure 20 shows a view similar to Figure 19 and shows the forces generated by the inlet fluid pressure acting on the sensing spindle and the valve member, with the valve still closed;

[0197] Figure 21 shows a view similar to Figure 19 in which the sensing spindle has moved upward to contact the valve member,

[0198] Figure 22 shows a view similar to Figure 21 in which the sending spindle has engaged the valve member and the inlet pressure has risen to the point where the valve member opens and the fluid pressure is released from the inlet to the outlet. DETAILED DESCRIPTION

[0199] Reference will now be made to Figure 1 and Figure 18 to discuss the preferred embodiments.

[0200] Figures 1 to 9 A first variant of the pressure reducing valve 1 is shown in Figures 10 to 15 and its operating principle is shown in. In Figure 1 the valve 1 generally shown has a valve body 4 and an inlet 2 leading into the interior 5 of the valve body 4, and an outlet 3 from the interior 5. A valve cap 39 is connected to the valve body 4. The valve cap 39 can be attached to the valve body 4 in any number of ways, and in the variant shown here, a valve cap fastener 40 such as a bolt passes through the valve cap 39 into the threaded portion of the valve body 4 and holds the two together. Contained within the valve cap 39 is a second biasing 17 for the sensing spindle 15, which will be explained in more detail below.

[0201] On top of the valve cap 39, there is a valve cap cover 41, such as Figure 4 , 5, as shown in Figures 7 and 8. The valve cap cover 41 can be attached in any desired manner, such as by press fit, bayonet, threading, or other means. Optionally, although not ideally without the valve cap cover 41, this may allow corrosion and contamination of components that would otherwise be covered. For the adjustable bias 17, the valve cap cover covers the second bias regulator 42, and the form of the regulator 42 will depend on the selected bias. In the illustrated variant, the bias 17 is a helical spring that acts compressively on the sensing spindle 15. In this case, the adjusting member 42 is a threaded rod that engages a nut or similar threaded component in the valve cap 39 or the valve cap cover 41. Optionally, there may be a lock nut (not shown) to prevent vibration or otherwise change the regulator. The regulator 42 will advance or retract relative to the bias 17 and thus increase or decrease the force exerted by the spring 17 on the sensing spindle 15, thereby adjusting the set point (discussed further below). Other methods of adjusting the spring bias may also be used, such as a rotating crown with different step heights. The bias can take any of a variety of other forms that are also suitable for generating an increased or decreased force on the sensing spindle, such as but not limited to passive compression or tension springs, gas or air-driven springs, or electromechanical systems.

[0202] The closure of the interior 5 of the valve body is shown in Figure 6 and is shown in exploded form in Figure 7 and 9 The interior 5 houses the valve member 7, the sensing spindle 15, and the first bias 13. As shown, the valve member 7 is of an annular or circular shape about the longitudinal axis 31, and the sensing spindle 15 is also located on this axis 31, and both slide independently along this axis. The valve member 7 and the sensing spindle 15 are radially symmetric, so when pressure is applied, they are inherently balanced laterally and remain parallel in their movement.

[0203] The valve member 7 is energized by the first bias 13 to its first valve position 14 as shown in Figure 6 . This creates an initial seal 21 from the inlet 2 of the chamber 28 (preferably annular), shown in Figure 16 , which in turn leads to the outlet 3. As shown in Figure 10 , the first sealing surface 12 of the valve member 7 seals 21 against the inlet sealing surface 25. In this example, there is a first sealing surface 12 - in the variant shown in Figures 13 to 15 , there is an inlet insert 43 that holds the inlet sealing surface 25. In this variant, the inlet insert 43 is threadedly connected and sealed to the valve body 4, however, any suitable holding and sealing method may be used, such as but not limited to interference fit, adhesive, or similar methods.

[0204] As shown in Figure 10 and 16As shown, the valve member 7 has one or more fluid passages 30 from a first pressure surface 8 on a first side 9 to a second pressure surface 11 on a second side 11. These allow the inlet pressure to act on the first and second sides of the valve member 7 and form a net first pressure region that acts with the inlet fluid pressure and the outlet fluid pressure to increase the force acting on the seal 21 as the inlet pressure increases.

[0205] The first pressure region 23 is determined by the net area of the sensing spindle 15 facing the fluid pressure in the inlet 2, as Figure 10 , 13 and as shown in 19, and is defined by a diameter or perimeter D3. The second pressure region 22 is, for example, the region of the first pressure surface 8 on the first side 9 defined by a diameter or perimeter D2 in Figure 10 and 19 minus the region of the second pressure surface 10 of the second side 11 of the valve member 7 defined by a diameter or perimeter D1 in Figure 10 and 19 , the diameter or perimeter D1 being greater than the diameter or perimeter D2. Since the second pressure surface 10 is greater than the first pressure surface 8, when the valve member is closed, the valve member 7 has a net closing force 47, Figure 13 and this net closing force in forces the valve member 7 downward in the direction of the arrow shown.

[0206] The valve member 7 is in sliding sealing engagement within the valve 1 such that when the valve member moves from a first valve position 14 (shown, for example, in Figure 10 and 13 ) to or towards a second valve position 24 (shown, for example, in Figure 14 ), even though the only path from the second side 11 to the outlet 3 is via an opening formed between the first sealing surface 12 and the inlet sealing surface 25 of the valve member 7. In the variant shown in Figure 6 , there is a stop 29 that forms a sliding seal with the valve member 7 in this way and also holds or guides a first bias 13 between itself and the valve member 7. In this variant, the stop 29 is held in place by a release in the valve body 4 and the valve cap 39 above.

[0207] The stop 29 also serves as a stop for a second bias 17 that acts on the sensing spindle 15 via the second bias 17, as Figure 6 shown, the second bias 17 acting via a stop portion 34 that engages between the stop 29 and the second bias 17 and moves with the second bias 17 and the sensing spindle 15. The sensing spindle 15 provides the second pressure region 23 to attain the pressure of the inlet fluid.

[0208] As can be seen and understood from the above description, the first bias 13 and the second bias 17 are independent and do not act on each other.

[0209] The sensing spindle 15 is energized by the second bias 17 and held in its first spindle position 18, and is guided to be parallel to the axial center 31 by passing through the middle of the stop 29, as Figure 6 shown. At least as Figure 6 and 10 shown, through Figures 1 to 17 one of the fluid orifices 30 in the variant in

[0210] The sensing spindle 15 as described above can engage the valve member 7 to move it and cause the valve member 7 to rupture and open. The sensing spindle 15 has a shoulder 48 (in this embodiment of the second pressure region 23, the shoulder 48 is located on the rear side). In this embodiment, the shoulder 48 engages the valve member 7 to move and open the valve member 7.

[0211] The sensing spindle 15 can move from its first spindle position 18 ( Figure 6 shown) to or towards a second spindle position 20 ( Figure 15 shown). In a preferred variant, midway through this movement, the sensing spindle 15 will engage the valve member 7. This is achieved by the cross-section 32 being wider than the central fluid passage 30 of the valve member 7, as Figure 6 and Figure 15 shown, the valve member 7 passes through the central fluid passage 30. The sensing spindle can engage the valve member in any other way such that due to the movement of the sensing spindle towards the second spindle position 20, it contacts and moves the valve member 7, thereby moving the valve member 7 to and towards the second valve position 24 and bringing the valve member 7 into a fully open state.

[0212] During the movement of the sensing spindle and the valve member, the stop 29 does not move.

[0213] When the pressure reducing valve 1 is not in use, or on a storage shelf, or connected but not receiving a net higher inlet pressure, it has a very low sealing force due to only the first bias 13 acting. This holds the sealing material as no seal or sealing interface (e.g., the valve first sealing surface 12 of the valve with the inlet sealing surface 25) is under a very low static load. The sealing load only increases proportionally to the net difference between the inlet and outlet fluid pressures.

[0214] The valve member 7 or the sensing spindle 15 must preferably be guided during its movement, and can be guided on the valve cap 39, nozzle or sensing spindle, on the inner or outer surface of each valve cap, nozzle or sensing shaft during its movement. The guiding features and shapes of these elements can be such that the flow capacity of the valve is throttled or otherwise increased via the position of the valve.

[0215] As an example of this situation, the valve member 7 can have an extension as a skirt (not shown) that extends downward from the lower periphery of the first pressure surface 8 (see Figure 10 ) into the inlet 2 and engages the inner periphery of the inlet / seal over the range of movement from the first valve position 14 to the second valve position 24. The skirt (if present) can provide lateral stability to the valve member 7 and guide the valve member 7. When moving from the first valve position 14, the orifice through the skirt will still allow fluid to flow from the inlet to the outlet. Such a skirt can help throttle the discharge rate during initial opening.

[0216] The fluid passage 30 can also diagonally cross the valve member 7 from the second pressure surface 10 to the first pressure surface 8 and be inclined toward the outlet such that when initially displaced from the first valve position 14, for example when the valve member is in pre-ignition, i.e., when only fluid pressure is released, the fluid passage 30 allows the initial release of the inlet fluid pressure from behind the valve member. In one form, these fluid passages can be sealed relative to the inlet seal surface 25. These fluid passages can be a first path for releasing the inlet fluid pressure during the initial movement of the valve member from the first valve position until deeper into the movement toward the second valve position 24.

[0217] Figure 17 A variant of the valve 1 is shown that uses a bellows or rolling seal 44 between the valve member 7 and the valve body.

[0218] In a preferred variant of the present invention, for example Figure 19 as shown in, removal of the valve cap 39 will allow the stop 29, the sensing spindle 15, the valve member 7, the spring 13, and the inlet insert 43 to all be removed as a sub-assembly or cartridge. This allows for easy servicing - a new valve cap sub-assembly can be installed into the valve body 4, which can remain in place. Thus, a failed valve or valve maintenance can be easily achieved by removing the existing sub-assembly and inserting a new one. Then, the existing sub-assembly can be repaired as needed. The extractable cartridge or sub-assembly contains all replaceable and repairable parts. The cartridge or sub-assembly incorporates all soft seals and moving parts that can be removed as a unit, which significantly improves maintainability compared to the prior art.

[0219] In Figures 19 to 22Another variant incorporating the same operations and features of the present invention is shown. In this variant, when the valve member 7 is opened and overlaps with the stopper 29 and the valve member 7 through the stopper 29, the first bias 13 is protected from the fluid when the fluid passes through the inlet. The stopper 29 and the valve member 7 largely or completely encapsulate the bias 13. The opening of the valve member 7 can be a rather violent pressure event and release, and this protects them from corrosion, corrosiveness, or particles therein. This is beneficial when the valve member and the spring 13 are no longer exposed to high-speed turbulence and will now meet the requirements set forth in ASME VIII.

[0220] This further variant has a flat surface sealing surface. The flat (e.g., polished) surface of the nozzle or inlet insert 43 and the sealing surface 25 between it and the valve member 7 provide sufficient sealing surface area to allow for relaxed tolerances (especially concentricity requirements). An additional benefit of this variation is that the pressure region and thus the performance of the valve do not depend on the position where the face seal contacts the inlet insert 43; misalignment due to tolerances does not affect the pressure bias. Misalignment of the face seal diameter or perimeter, the piston permanent seal, and the sensing mandrel seal with each other has no effect on the pressure bias system and the performance of the valve. The dimensional / geometric tolerances of their diameters or perimeters have a direct impact, namely the pressure region as previously defined.

[0221] The pressure reducing valve 1 of the present invention can be described by a pressure region defined by a perimeter or diameter (or other dimension if a non-circular arrangement is used). In this way, the pressure reducing valve operates to prevent fluid from flowing from the inlet (or first port) 2 to the outlet (or second port) 3 until the pressure difference between the inlet 2 and the outlet 3 reaches a set point. The inlet 2 of the valve body leads to the interior of the valve body, and the outlet 3 exits from this interior, as Figure 4 , 10 , 13 and 19 are not all shown. The valve cap 39 is removably engaged to the valve body, for example using Figure 4 the fastener 40 in, but a threaded interface as in Figure 18 can also be used. The valve body and the valve cap 40 define a conduit or chamber 28 therebetween, which is annular or toroidal (i.e., circular ring-shaped) in the example shown. The valve member 7 has an annular valve skirt 49 (as Figure 10 shown) or wall within the conduit or chamber 28. The annular skirt 49 has an outer perimeter that is circular in the example shown but can be of any shape, and the valve body 4 at least partially defines the annular chamber 28. The annular skirt 49 has an inner perimeter that defines an inner chamber 50. The valve member 7 has a closed position that prevents fluid flow and an open position that allows fluid flow, and the valve member is biased closed by a first bias 13. The annular skirt 49 is at a first seal diameter or perimeter D1 when the valve cap is inFigure 10 shown as the inner diameter or perimeter of chamber 50, or in other cases, the seal may be on the outer diameter or perimeter of valve skirt 49), the valve cap is in sliding and sealing engagement at the open and closed positions and between the open and closed positions. This defines the second pressure surface 10. The valve member 7 has a sealing surface 25 which, when in the closed position, seals against the valve body 4 at the second sealing diameter or perimeter D2, as Figure 10 shown. The area within the perimeter of the sealing diameter (if circular) or perimeter defines the first pressure surface 8. The first sealing diameter (or perimeter) or second pressure surface 10 is greater than the second sealing diameter (or perimeter) or first pressure surface 8, and the net difference defines the first pressure region 22. When fluid is received into the inner chamber under pressure, the first pressure region 22 provides a bias towards the closed position, preferably in addition to the first bias 13. When the valve member 7 is in the open position, an opening is defined between the valve body 4 and the valve member 7 to allow fluid to flow between the first ports through the opening to the second ports, such as Figure 15 shown, where fluid 51 escapes through opening 27. The central or sending mandrel 15 is in sliding and sealing engagement with the valve cap 39 or a portion thereof at a third sealing diameter or perimeter (D3) which is less than the second sealing diameter or perimeter D2. The third sealing diameter or perimeter (D3) defines a second pressure region 23 which provides a bias towards the open position when receiving pressurized fluid 51. Thus, in use, the valve 1 has inlet fluid 51 acting on the second pressure surface 23 which acts against the second bias 17. When the inlet pressure exceeds the set pressure, the sensing mandrel 15 moves to or towards the second mandrel position and acts on the first bias force 47, that is, subtracts from the first bias force 47, and breaks the seal at the first sealing diameter or perimeter 25, and the inlet fluid can flow out to the outlet.

[0222] A method of reducing valve operation will now be described with reference to Figures 13 to 15 ...

[0223] The first pressure region 22 receives pressurized fluid at least from the inlet 2, or fluid at a net higher pressure when the inlet 2 is compared to the outlet 3. The net higher inlet pressure and outlet pressure act on the first pressure region 22 to increase the sealing or net closing force 47 of the valve member 7 against the inlet sealing surface 25. Thus, as the net pressure difference (between the inlet and outlet) increases, the force sealing the valve member 7 against the inlet sealing surface 25 will close when the inlet pressure is below the set pressure. In Figure 13 ... is shown the position of valve 1 when the pressure difference between the inlet and outlet is below the set pressure.

[0224] The valve member (at Figure 11 andFigure 12 The initial sealing force (referred to as the dose valve in the graph) as a percentage of the maximum sealing force (which is reached exactly when the set pressure is reached) is at Figure 12 shown as the top blue line (1) in the graph of

[0225] The set pressure is determined by the second pressure region 23 of the sensing spindle 15 and the second bias 17. This is the pressure at which the valve will release or open at the inlet and allow pressure to be released from the inlet to the outlet. Increasing the force provided by the second bias 17 (e.g., by switching to a spring with a higher spring constant, or using a regulator 42 to wind more force on it), or decreasing the second pressure region 23 will increase the set pressure.

[0226] As the inlet pressure increases, the force 47 of the sealing valve 7 increases, and when the force equals the pressure multiplied by the area, the force acting on the sensing spindle 15 also increases. As the pressure (bar) increases, the movement of the sensing spindle 15 (referred to as the sensing piston in Figure 11 ) is shown in Figure 11 In the region (1) before the set pressure (here 98 bar), the sensing spindle does not move and is in the position shown in Figure 13 At or near the set pressure (about 98 bar shown in the figure), the sensing spindle moves from its first spindle position 18, through an intermediate position (3) (shown in Figure 14 ), and then forward (4) to its second spindle position 20 (shown in Figure 15 ).

[0227] This initial movement of the sensing spindle 15 from its first spindle position 18 to the intermediate position is shown in Figure 14 - it can be seen that the stop 34 has lifted away from the stopper 29, and the sensing spindle 15 has moved upward to contact the valve member 7. This can be seen in Figure 11 where the position of the valve member 7 has moved to the solid black line representing zero (-0.2 represents the first spindle position 18.0.0 is the intermediate position when the sensing spindle 15 contacts the valve member 7).

[0228] When the inlet pressure continues to rise, the force exerted by the sensing spindle 15 on the valve member 7 increases. However, the sending spindle cannot move any further until it overcomes the first bias 13 acting on the valve member 7. Therefore, Figure 11 the graph in

[0229] Then, the pressure acting on the sending mandrel 15 reaches the set pressure (about 98 bar), which can overcome the combined force exerted by the first bias 13 and the second bias 17. At this time, as Figure 14 shown, the sensing mandrel 17 and the valve member 7 can move as a unit towards their respective second mandrel positions 20 and the second valve position 24, and the valve 1 lifts off its seat, (traveling along the Figure 12 and 11 curve portion (4) therein) opens, and the pressure is released from the inlet 2 to the outlet 3.

[0230] When the inlet pressure drops below the set pressure, the movement reverses and the valve 1 closes.

[0231] In the Figure 18 variant shown, the inlet 2 enters from the side while the outlet 3 is at the bottom. The inlet fluid pressure is prevented from passing through the valve to the outlet 3 by an annular valve member 7 having a first sealing surface 12 that forms a seal 21 on the inlet sealing surface 25, which is part of the central, non-moving valve spindle 46. This seal can be formed by a soft seal, a hard seal, or a combination thereof. In the example shown, there is a soft inlet seal 25 and the first sealing surface 12 of the valve member is hard. The soft inlet seal 25 is energized by the inlet pressure to effect sealing, and its sealing pressure increases proportionally with the inlet pressure.

[0232] The first pressure region 22 on the valve 7 is again acted upon by the net pressure difference between the inlet fluid and the outlet fluid to drive the valve 7 to the sealing position in the first valve position 14, and the sealing force 47 again increases as the inlet pressure difference to the outlet pressure increases. The valve member 7 is connected to the central valve spindle 45 by at least one radial vane (not shown). The valve spindle 45 is in turn biased by a first bias 13 to seal at the first valve position 14 as Figure 18 shown. The valve member 7 has an outer diameter or peripheral seal 36 that slidably seals to the inner diameter or periphery of the valve body 4. If desired, an actuator can act on the valve spindle 45 to manually open the valve.

[0233] The annular chamber 100 between the sensing spindle 15 and the valve body has a net differential pressure region between its upper and lower seals. The sensing spindle 15 is in sliding engagement with the valve body and is capable of carrying the valve spindle 45 and the valve 7. The annular chamber 100 receives an increased inlet pressure through the fluid passage 30, and this inlet pressure acts on the net differential pressure region in the annular chamber 100 to resist the second bias 17. At the set pressure, the inlet fluid in the annular chamber 100 will overcome the second bias 17, and the sensing spindle will move from the first spindle position 18 as shown in the direction towards the outlet 3 to a second spindle position (not shown). When moving from the first spindle position 18, the valve member 7 is contacted and opened, and the fluid in the inlet 2 can then flow to the outlet 3 to relieve the pressure.

[0234] When the pressure rises, the following occurs:

[0235] Low pressure below the set pressure

[0236] The sensing spindle 15 does not contact the valve member 7, and the first bias 13 and the inlet pressure keep the valve member 7 closed. The second bias 17 holds the sensing piston against its hard stop.

[0237] Medium pressure, not close to the set point

[0238] No change - the pressure is still not high enough to move anything, but the valve member 7 is held more firmly in its seat by the action of the first pressure region that forms and increases the closing force 47.

[0239] Almost at the set pressure

[0240] The sensing spindle 15 (independently) moves towards the (stationary) valve member 7 and contacts the (stationary) valve member 7, but the inlet pressure is not sufficient to overcome the first bias 13 and the pressure 47 acting on the valve member 7.

[0241] Reach the set pressure

[0242] The sensing spindle pressure region (second pressure region) is greater than the valve member pressure region (first pressure region) and is high enough to overcome the first bias 13 and the second bias 17 (spring), and the sensing spindle 15 contacts and lifts the valve member 7 and opens the valve 1.

[0243] Therefore, the present invention has a pressure sensing function accomplished by the sensing spindle 15, which is a movable element separate from the element (valve member 7), and the position of this element defines whether the valve is open or closed. The sensing piston (sensing rod / spindle 15) moves independently of the flow control element (valve 7).

[0244] The diameter or perimeter of the sensing piston 7 (second pressure region 23) is independent of the diameter or perimeter of the piston seal (first pressure region 22), which means that a much smaller pressure sensing area can be used to control an equivalent flow area, thus greatly reducing the spring force (and thus valve size and material cost) requirements for a given flow capacity requirement.

[0245] A substantially cylindrical piston having a cylindrical sealing surface that engages the valve cap and an annular sealing surface that engages the seat, which may be part of the body or part of the nozzle assembly.

[0246] The sensing rod 15 passes through the valve piston 7 and is assembled through the valve cap. In the "closed" position, when viewed in the orientation of at least Figure 13 the sensing piston is in the lowered position and does not contact or press on the valve piston 7. The valve piston 7 is held in the closed position by the seating spring 13 and also by the pressure generated by the inlet pressure acting on the second pressure region 22 (generated by the difference between the diameter or perimeter between the cylindrical sealing surfaces of the piston and the effective sealing diameter or perimeter between the seat and the seal).

[0247] When approaching the set pressure, the valve piston 7 is pressed into the seat with a higher force (due to the high pressure) by the sealing force 47 proportional to the inlet pressure, thus ensuring a reliable seal between the components and preventing flow / leakage.

[0248] Once the set pressure is reached, the sensing rod 15 moves (upward in Figure 14 and downward in Figure 18 ) and contacts the valve piston 7, and pushes it upward ( Figure 14 ) or downward ( Figure 18 ), compressing the valve piston seating spring and opening the valve.

[0249] By moving the valve piston, the inlet chamber and the outlet chamber are connected, thus opening the valve and "bleeding" the inlet to the outlet.

[0250] The effective sealing diameter or perimeter of the piston (on the face seal and the cylindrical sliding seal) is substantially the same, which means that the pressure in the discharge chamber of the valve has little or no effect on the performance and / or behavior of the valve.

[0251] The new pressure reducing valve design operates in a manner similar to a traditional direct acting valve in that the pressure regions act via the incoming pressure resistance reference spring, with a key difference being that the pressure sensing operation is done through the sensing spindle 15, which is a movable element separate from the valve member 7, the position of which defines whether the valve is open or closed (valve piston).

[0252] The sensing piston (sensing rod) 15 moves independently of the flow control element 7 (piston).

[0253] The diameter or perimeter of the sensing piston is independent of the diameter or perimeter of the piston seal, which means that a much smaller pressure sensing area can be used to control an equivalent flow area, greatly reducing the spring force (and thus valve size and material cost) requirements for a given flow capacity requirement.

[0254] The two seals of the valve piston (its permanent seal [sometimes called its piston seal] and face seal) closely match in diameter or perimeter, creating a small residual pressure area that is used to keep the valve closed when the inlet pressure rises compared to the outlet pressure.

[0255] The piston has its own seating spring / bias that provides an initial seating force to create a seal between the piston and the nozzle. When the pressure rises, a larger proportion of the seating force of the valve piston will be due to pressure rather than other biasing from the spring force.

[0256] Increasing pressure is used to hold the piston on its seat (nozzle) until the sensing piston starts to act on the piston to lift it and open the valve.

[0257] This layout is very similar geometrically to traditional valves, so there is a high degree of compatibility and interchangeability with popular traditional pressure reducing valves. It is feasible to convert a traditional pressure reducing valve to use the pressure reducing valve of the present invention.

[0258] The conceptual design of a pressure sensing overpressure relief valve in the closed and open states is described. The key aspects of the design to note are:

[0259] - The "dose valve" element is balanced with respect to the inlet and discharge pressures.

[0260] - The sensing path is completely contained within the valve and does not require external sensing hardware (such as a pilot valve in the prior art)

[0261] - The valve structure is suitable for in-line maintenance, with the adjustment parts assembled on one side of the valve

[0262] - The valve body will be easily adaptable to a solenoid actuator or any other type of actuator without significant updates to the adjustment parts, and a simple adapter is used to switch between actuation methods.

[0263] A new type of pressure reducing valve that is similar in size to existing types of valves, but offers benefits over both:

[0264] Compared to traditional PRVs

[0265] · Improved seat tightness and pre-ignition performance compared to traditional pressure reducing valves without increasing the cost and complexity of the PO PRV (pilot-operated pressure reducing valve).

[0266] · Balanced discharge pressure without using fragile and expensive multi-layer metal bellows.

[0267] · Cost-effectiveness relative to large and high-pressure traditional PRVs due to smaller force and spring requirements.

[0268] · Significantly reduced seating force - reduces the load on the soft seat and prevents set pressure variations.

[0269] Pilot-operated PRV

[0270] · Achieves similar performance in a more "familiar" and simple system - more like a traditional PRV.

[0271] · All products except the largest PO PRV are significantly cost-effective.

[0272] · Due to the absence of a sensing tube, the valve can be used with viscous or dirty fluids, or in applications requiring CIP, thus opening up a wider set of use cases.

[0273] The present invention has the following advantages: It is inherently well-balanced, substantially reducing the actuator force required. The reference force spring or actuator does not act on the sealing element until the valve is actuated, which means the sealing element is isolated from high seating loads when not needed, and a fully balanced valve can be achieved simply and inexpensively by adding or removing a specific seal from the dosing valve itself without the need for additional components.

[0274] The valve according to the present invention is smaller, has a lower cost, and lower force, so a safer spring can be used. The flow rate (seat diameter or perimeter), pressure, and spring force are no longer related in the same way - resulting in the ability to significantly reduce the required spring force while maintaining the same flow rate.

[0275] The present invention includes a seal for achieving the same balanced performance as other types of balanced control valves. However, the hermetically sealed bellows rod seal (shown in Figure 17 can be of a much smaller diameter or perimeter and is therefore less expensive than an equivalent traditional bellows seal - and the use of a sliding piston seal does not represent a fugitive emissions risk. Due to the very low friction of the rolling diaphragm piston seal, the rolling diaphragm piston seal is also an attractive seal option in this layout.

[0276] The minimum reclining force is defined by the preload of the reclining spring 13, (which also prevents the valve element from clicking / moving and being damaged during transportation or handling). When the inlet pressure increases, the piston is pressed into its seat with an increasing force 47, thus maintaining a high sealing integrity. The force balance on the piston switches - opening the valve only when the sensing rod 15 has been displaced by the inlet pressure against its force reference spring 17 to the extent that the sensing piston contacts the valve piston.

[0277] No additional piping, valves, components are required - the valve of the present invention can simply be positioned in place of a pre-existing valve and the set pressure adjusted (if not already).

[0278] The present invention has been described including its preferred forms. Modifications may be made thereto without departing from the scope of the invention.

Claims

1. A pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including, a. A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior, b. A valve member operably positioned within the valve body, the valve member having a first pressure surface on its first side in fluid communication with the inlet fluid and a second pressure surface on its second side, the second pressure surface being opposite the first surface and also in fluid communication with the inlet fluid, and a first sealing surface on the first side to seal off the inlet from the outlet, c. A first biasing force that urges the valve member to a first valve position, whereby the first biasing force seals the inlet and outlet apart, d. A sensing spindle in fluid communication with the inlet fluid, the sensing spindle having a third pressure surface in fluid communication with the inlet fluid, and a second biasing force that urges the sensing spindle to a first spindle position against the inlet fluid pressure acting on the third pressure surface, the second biasing force not adding to the first biasing force, e. Such that in use, the inlet fluid acting on the second pressure surface adds to the first biasing force in sealing the first sealing surface to the inlet, and f. When the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position, the second spindle position breaking the seal between the first sealing surface and the inlet, and the inlet fluid being able to flow out to the outlet.

2. The valve according to claim 1, wherein when under pressure but below the set pressure, the inlet fluid acting on the second pressure surface creates a force greater than the first biasing force in sealing the first sealing surface to the inlet.

3. A pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including, A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior, A valve cap removably engageable to the valve body between the first port and the second port so as to further define a conduit therebetween, A valve member having an annular skirt within the conduit, the annular skirt having an outer perimeter, the valve body at least partially surrounding the outer perimeter to define an annular chamber, and the annular skirt having an inner perimeter that defines an inner chamber, the valve member having a closed position preventing fluid flow and an open position allowing fluid flow, The annular skirt slidingly and sealingly engaging the valve cap at a first sealing diameter or perimeter at the open position and the closed position and between the open position and the closed position, The outer base of the valve member sealingly abutting the valve body at a second sealing diameter or perimeter when in the closed position, The first sealing diameter or perimeter is greater than the second sealing diameter or perimeter, and a first pressure region is defined between the first sealing diameter or perimeter and the second sealing diameter or perimeter. The first pressure region provides a bias towards the closed position when receiving fluid into the inner chamber under pressure. When in the open position, an opening is defined between the valve body and the valve member to allow fluid to flow between the first ports through the opening to the second ports. A sensing spindle that slidably and sealingly engages with the valve cap at a third sealing diameter or perimeter (D3), the third sealing diameter or perimeter (D3) defining a second pressure region that provides a bias towards the open position when receiving pressurized fluid. Such that in use, the inlet fluid acting on the second pressure surface subtracts from the first biasing force during the process of sealing the first sealing surface to the inlet, and when the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position that breaks the seal at the first sealing diameter, and the inlet fluid can exit to the outlet.

4. The valve according to claim 3, wherein the valve member is biased closed by a first bias, and in addition to the first bias, the first pressure region also provides a bias from the pressurized fluid. The third sealing diameter is smaller than the second sealing diameter, and there is a second bias acting on the sensing spindle relative to the inlet fluid acting on the second pressure surface.

5. A pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including, a. A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior. b. A valve member operatively positioned within the valve body, the valve member having a first pressure surface on its first side that is in fluid communication with the inlet fluid, and a second pressure surface on its second side that is opposite the first surface and also in fluid communication with the inlet fluid. The difference between the first pressure surface and the second pressure surface defines a first pressure region on which the inlet pressure and the outlet pressure act. A first sealing surface on the first side to sealingly isolate the inlet from the outlet. c. A first biasing force that urges the valve member to a first valve position, whereby the first biasing force seals the inlet and the outlet open. d. A sensing spindle that is in fluid communication with the inlet fluid, the sensing spindle having a second pressure region in fluid communication with the inlet fluid, and a second biasing force that resists the inlet fluid pressure acting on the second pressure region from urging the sensing spindle to a first spindle position, and the second biasing force does not add to the first biasing force. e. This causes, in use, the pressure difference between the inlet and outlet fluids acting on the first pressure region to add to the first biasing force when sealing the first sealing surface to the inlet, and f. wherein when the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position by the action of the inlet pressure on the second pressure region, thereby acting on the valve member to create a separation between the valve member and the sealing surface and enabling flow between the inlet and the outlet.

6. The pressure reducing valve according to any one of claims 1 to 5, wherein the sensing spindle acts on the valve member to move the valve member to or towards a second valve position.

7. A pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including, a. A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior, b. A valve member operatively positioned within the valve body, the valve member having a first pressure region on which the inlet pressure and the outlet pressure act, and a first sealing surface on the first side to seal off the inlet from the outlet, c. A first biasing force that urges the valve member to a first valve position, whereby the first biasing force seals off the inlet from the outlet, d. A sensing spindle in fluid communication with the inlet fluid, the sensing spindle having a second pressure region in fluid communication with the inlet fluid, and a second biasing force that resists the inlet fluid pressure acting on the second pressure region to urge the sensing spindle to a first spindle position, the second biasing force not adding to the first biasing force, e. This causes, in use, the pressure difference between the inlet and outlet fluids acting on the first pressure region to add to the first biasing force when sealing the first sealing surface to the inlet, and f. wherein when the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position by the action of the inlet pressure on the second pressure region, thereby acting on the valve member to create a separation between the valve member and the sealing surface and enabling flow between the inlet and the outlet.

8. The pressure reducing valve according to any one of claims 1 to 7, wherein the valve member has a first pressure surface on its first side in fluid communication with the inlet fluid and a second pressure surface on its second side opposite the first surface also in fluid communication with the inlet fluid, and the difference between the first and second pressure surfaces defines the first pressure region.

9. A pressure reducing valve that operates on an inlet pressurized fluid to prevent and allow the inlet fluid to flow from the inlet to the outlet, the pressure reducing valve comprising or including, a. A valve body having an inlet leading to the interior of the valve body and an outlet leading away from the interior, b. A valve member operatively positioned within the valve body, the valve member having a first pressure region upon which the inlet pressure and the outlet pressure act, a first sealing surface located on a first side of the valve member for sealing against the inlet sealing surface and sealingly isolating the inlet from the outlet, c. A first biasing force that urges the valve member to a first valve position, whereby the first biasing force is capable of sealingly opening the inlet from the outlet, d. A sensing spindle in fluid communication with the inlet, the sensing spindle having a second pressure region in fluid communication with the inlet fluid, a second biasing force urging the sensing spindle to a first spindle position against the inlet fluid pressure acting on the second pressure region, the second biasing force not adding to the first biasing force, e. Such that in use, the pressure differential between the inlet and the outlet fluid acting on the first pressure region adds to the first biasing force to sealingly isolate the inlet from the outlet, and f. Wherein in use when the inlet pressure exceeds a set pressure, the sensing spindle moves to or towards a second spindle position via the action of the inlet pressure on the second pressure region, whereby acting on the valve member to create a separation between the first sealing surface and the inlet sealing surface and enabling fluid to flow between the inlet and the outlet.

10. The pressure reducing valve according to any one of claims 1 to 9, wherein there is a first pressure surface on a first side of the valve member in fluid communication with the inlet fluid, and a second pressure surface on a second side of the valve member opposite the first pressure surface also in fluid communication with the inlet fluid, the net difference between the first and second pressure surfaces defining the first pressure region upon which the inlet pressure and the outlet pressure act.

11. The pressure reducing valve according to any one of claims 1 to 10, wherein the pressure differential between the inlet and the outlet fluid acting on the first pressure region produces a net pressure in addition to producing the first biasing force for sealing the valve member.

12. The pressure reducing valve according to any one of claims 1 to 11, wherein there is a third pressure surface on the sensing spindle defining the second pressure region.

13. The pressure reducing valve according to claims 1 to 12, wherein the separation of the first sealing surface and the inlet sealing surface reduces the net force provided by the first pressure region, such that the first sealing surface and the inlet sealing surface are further separated by the sensing spindle to enable fluid to flow between the inlet and the outlet.

14. The pressure reducing valve according to claims 1 to 13, wherein the first and / or second biasing is adjustable.

15. The pressure reducing valve according to claims 1 to 14, wherein the first biasing is a spring or other elastic or similar biasing that is capable of providing an initial force to hold the first sealing surface against the inlet sealing surface.

16. The pressure reducing valve according to claims 1 to 15, wherein the sensing spindle is substantially housed within the valve member.

17. The pressure reducing valve according to claims 1 to 16, wherein the area of the second pressure surface is larger than the area of the first pressure surface to increase the force for keeping the valve member sealed.

18. The pressure reducing valve according to claims 1 to 17, wherein the area ratio of the first pressure surface to the second pressure surface can be adjusted through the inlet to change the energizing force for closing the valve member.

19. The pressure reducing valve according to claims 1 to 18, wherein there is an annular chamber fluidly communicating with the outlet around the valve member.

20. The pressure reducing valve according to claims 1 to 19, wherein the pressure surface of the second pressure region or the mandrel is used to overcome the combined closing force of the first bias and the resultant force of the first pressure region and the inlet pressure and the outlet pressure acting thereon to move the valve member from the first valve position and open the seal of the valve member.

21. The pressure reducing valve according to claims 1 to 20, wherein the valve member is an annular member and the first sealing surface is close to the inlet.

22. The pressure reducing valve according to claims 1 to 21, wherein the first sealing surface is an annular surface.

23. The pressure reducing valve according to claims 1 to 22, wherein the inlet sealing surface is annular to cooperate with the first sealing surface.

24. The pressure reducing valve according to claims 1 to 23, wherein there is at least one fluid passage between the first pressure surface and the second pressure surface.

25. The pressure reducing valve according to claims 1 to 24, wherein the fluid passage is within the perimeter of the first sealing surface such that there is no fluid communication to the outlet when the first sealing surface seals to the inlet sealing surface.

26. The pressure reducing valve according to claims 1 to 25, wherein the first biasing force is provided by a helical spring positioned around the outer surface of the valve member.

27. The pressure reducing valve according to claims 1 to 26, wherein the second biasing force is provided by a helical spring.

28. The pressure reducing valve according to claims 1 to 27, wherein there is a stop to hold the sensing mandrel in the first mandrel position against the second biasing force.

29. The pressure reducing valve according to claims 1 to 28, wherein the force of the second bias is adjustable to partially allow adjustment of the set pressure.

30. The pressure reducing valve according to claims 1 to 29, wherein when the inlet fluid pressure increases but remains below the set pressure, the first pressure region increases the force for keeping the valve member sealed.

31. The pressure reducing valve according to claims 1 to 30, wherein the at least one fluid passage is located at the axial center of the valve member and the sensing mandrel passes through the at least one fluid passage towards the inlet.

32. The pressure reducing valve according to claims 1 to 31, wherein the sensing mandrel and the valve member are translated along the longitudinal axis from their respective first positions to their respective second positions.

33. The pressure reducing valve according to claims 1 to 32, wherein the annular member defining the valve member, the first sealing surface and the inlet sealing surface are concentric with the longitudinal axis.

34. The pressure reducing valve according to claims 1 to 33, wherein there is an additional fluid passage between the first pressure region and the second pressure region.

35. The pressure reducing valve according to claims 1 to 34, wherein when the sensing spindle moves from its first position to its second position or towards its second position, a cross-section of the sensing spindle located upstream of the valve member can be used as a pawl to engage and open the valve member.

36. The pressure reducing valve according to claims 1 to 35, wherein the diameter or perimeter of the cross-section is greater than the diameter or perimeter of the fluid passage through which the sensing spindle passes, so that the sensing spindle can engage and move the valve member.

37. The pressure reducing valve according to claims 1 to 36, wherein the stop is also used to form the annular chamber and is sealed to the inner perimeter of the annular chamber.

38. The pressure reducing valve according to claims 1 to 37, wherein the sensing spindle and the valve member are in separate sliding seals with the stop.

39. The pressure reducing valve according to claims 1 to 38, wherein the sensing spindle has a stop portion that engages with the stop to hold the sensing spindle in the first spindle position against the second biasing force.

40. The pressure reducing valve according to claims 1 to 39, wherein there is a guide skirt on the valve member that extends to or into the inlet and slidably engages with the inlet to guide the valve member when the valve member seals and unseals.

41. The pressure reducing valve according to claims 1 to 40, wherein the guide skirt engages with the inlet in a sliding seal.

42. The pressure reducing valve according to claims 1 to 41, wherein the fluid passage is unsealed during a first movement of the valve member towards the second valve position, and the valve skirt or its second fluid passage is unsealed during a second further movement of the valve member towards the second valve position.

43. The pressure reducing valve according to claims 1 to 42, wherein the valve member is balanced with respect to the inlet pressure and the outlet pressure.

44. A method of operating a pressure reducing valve to operate on an inlet pressurized fluid to prevent and allow inlet fluid to flow from the inlet to the outlet, comprising or including, a. Biasing a valve member to seal an opening from the inlet to the outlet, the valve member having a first pressure region on which the inlet fluid pressure can act to increase the sealing force of the valve member on its seat, in addition to the valve member being biased to seal the inlet and the outlet. b. Biasing a sensing spindle against the inlet fluid pressure acting on a second pressure region of the sensing spindle from the inlet, the biasing of the sensing spindle not increasing the biasing of the valve member, the biasing of the sensing spindle providing a set pressure at which the sensing spindle does not move, wherein, c. Below the set pressure, the sensing spindle does not contact the valve member, the valve member bias and the inlet pressure on the first pressure region hold the valve element sealed, and the sensing spindle bias holds the sensing piston against a hard stop, d. When approaching the set pressure, due to the action of the first pressure region, the valve member is pressed more forcefully into its seat, e. Just below the set pressure, the sensing spindle, independent of the valve member, moves towards the currently stationary valve member and contacts the currently stationary valve member, but the inlet pressure is not sufficient to overcome the valve member bias and the force of the first pressure region acting on the valve member, f. Once the set pressure is reached, the inlet fluid pressure on the second pressure region (greater than the first pressure region) is now high enough to overcome the valve member bias and the sensing spindle bias. The sensing spindle then moves the valve member to open the orifice and allow fluid flow between the inlet and the outlet, g. This provides a pressure reducing valve that has a low initial sealing pressure, and the sealing pressure increases with the inlet fluid pressure, thereby preventing inlet fluid from flowing to the outlet until the set pressure is reached, at which point the orifice is opened to allow fluid to flow from the inlet to the outlet.

45. A method of operating a pressure reducing valve to operate on an inlet pressurized fluid to prevent and allow inlet fluid to flow from the inlet to the outlet, comprising or including, a. Biasing a valve member to seal an orifice from the inlet to the outlet, the valve member having a first pressure region on which the inlet fluid pressure can act, in addition to the valve member bias to seal the inlet from the outlet, to increase the sealing force of the valve member on its seat, b. Biasing a sensing spindle against the inlet fluid pressure acting on a second pressure region of the sensing spindle from the inlet, the sensing spindle bias not increasing the valve member bias, the sensing spindle bias providing a set pressure at which the sensing spindle does not move, where, c. Below the set pressure, the sensing spindle does not contact the valve member, the valve member bias and the inlet pressure on the first pressure region hold the valve element sealed, and the sensing spindle bias holds the sensing spindle against a hard stop, d. Once the set pressure is reached, the inlet fluid pressure on the second pressure region (greater than the first pressure region) is now high enough to overcome the valve member bias and the sensing spindle bias. The sensing spindle then moves the valve member to open the orifice and allow fluid flow between the inlet and the outlet, e. This provides a pressure reducing valve that has a low initial sealing pressure, and the sealing pressure increases with the inlet fluid pressure, thereby preventing inlet fluid from flowing to the outlet until the set pressure is reached, at which point the orifice is opened to allow fluid to flow from the inlet to the outlet.

46. The method according to claim 44 or 45, wherein just below the set pressure, the sensing mandrel independent of the valve member moves towards the currently stationary valve member and contacts the currently stationary valve member, but the inlet pressure is not sufficient to overcome the valve member bias and the first pressure area force acting on the valve member.

47. The method according to any one of claims 42 to 46, wherein there is a first pressure surface in fluid communication with the inlet fluid on a first side of the valve member, and a second pressure surface also in fluid communication with the inlet fluid on a second side of the valve member opposite the first pressure surface, and the net difference between the first and second pressure surfaces defines a first pressure area on which the inlet pressure and the outlet pressure act.

48. The method according to any one of claims 42 to 47, wherein the pressure difference between the inlet and outlet fluids acting on the first pressure area generates a net pressure in addition to generating a first biasing force for sealing the valve member.

49. The method according to any one of claims 42 to 48, wherein there is a third pressure surface on the sensing mandrel that defines the second pressure area.

50. The method according to any one of claims 42 to 49, wherein the separation of the first sealing surface and the inlet sealing surface reduces the net force provided by the first pressure area, such that the first sealing surface and the inlet sealing surface are further separated by the sensing mandrel to enable fluid to flow between the inlet and the outlet.

51. The method according to any one of claims 42 to 50, wherein the first and / or second bias is adjustable.

52. The method according to any one of claims 42 to 51, wherein the first bias is a spring or other elastic or similar bias, and the spring or other elastic or similar bias can provide an initial force to hold the first sealing surface on the inlet sealing surface.

53. The method according to any one of claims 42 to 52, wherein the sensing mandrel is substantially housed within the valve member.

54. The method according to any one of claims 42 to 53, wherein the area of the second pressure surface is larger than the area of the first pressure surface to increase the force for holding the valve member in a sealed state.

55. The method according to any one of claims 42 to 54, wherein the area ratio of the first pressure surface to the second pressure surface can be adjusted by the inlet to change the energizing force for closing the valve member.

56. The method according to any one of claims 42 to 55, wherein there is an annular chamber in fluid communication with the outlet fluid around the valve member.

57. The method according to any one of claims 42 to 56, wherein the second pressure area or the pressure surface of the mandrel is used to overcome the combined closing force of the first bias and the resultant force of the first pressure area and the inlet pressure and the outlet pressure acting thereon to move the valve member from the first valve position and open the seal of the valve member.

58. The method according to any one of claims 42 to 57, wherein the valve member is an annular member and the first sealing surface is close to the inlet.

59. The method according to any one of claims 42 to 58, wherein the first sealing surface is an annular surface.

60. The method according to any one of claims 42 to 59, wherein the inlet sealing surface is annular to mate with the first sealing surface.

61. The method according to any one of claims 42 to 60, wherein there is at least one fluid passage between the first pressure surface and the second pressure surface.

62. The method according to any one of claims 42 to 61, wherein the fluid passage is within the perimeter of the first sealing surface such that when the first sealing surface is sealed to the inlet sealing surface, there is no fluid communication to the outlet.

63. The method according to any one of claims 42 to 62, wherein the first biasing force is provided by a helical spring disposed around the outer surface of the valve member.

64. The method according to any one of claims 42 to 63, wherein the second biasing force is provided by a helical spring.

65. The method according to any one of claims 42 to 64, wherein there is a stop to hold the sensing spindle in the first spindle position against the second biasing force.

66. The method according to any one of claims 42 to 65, wherein the second biasing force is adjustable to partially allow adjustment of the set pressure.

67. The method according to any one of claims 42 to 66, wherein when the inlet fluid pressure increases but remains below the set pressure, the first pressure region increases the force holding the valve member sealed.

68. The method according to any one of claims 42 to 67, wherein the at least one fluid passage is located at the axial center of the valve member and the sensing spindle passes through the at least one fluid passage towards the inlet.

69. The method according to any one of claims 42 to 68, wherein the sensing spindle and the valve member translate along a longitudinal axis from their respective first positions to their respective second positions.

70. The method according to any one of claims 42 to 69, wherein the annular member defining the valve member, the first sealing surface and the inlet sealing surface are concentric with the longitudinal axis.

71. The method according to any one of claims 42 to 70, wherein there is an additional fluid passage between the first pressure region and the second pressure region.

72. The method according to any one of claims 42 to 71, wherein when the sensing spindle moves from its first position to its second position or towards its second position, a cross-section of the sensing spindle located upstream of the valve member serves as a pawl to engage and open the valve member.

73. The method according to any one of claims 42 to 72, wherein the diameter or perimeter of the cross-section is greater than the diameter or perimeter of the fluid passage through which the sensing spindle passes, so that the sensing spindle can engage and move the valve member.

74. The method according to any one of claims 42 to 73, wherein the stopper is further configured to form the annular chamber and is sealed to the inner periphery of the annular chamber.

75. The method according to any one of claims 42 to 74, wherein the sensing mandrel and the valve member are in separate sliding seals with the stopper.

76. The method according to any one of claims 42 to 75, wherein the sensing mandrel has a stop portion that engages with the stopper to hold the sensing mandrel in the first mandrel position against the second biasing force.

77. The method according to any one of claims 42 to 76, wherein a guiding skirt is provided on the valve member, the guiding skirt extending to or into the inlet and slidingly engaging with the inlet to guide the valve member when the valve member is sealing and unsealing.

78. The method according to any one of claims 42 to 77, wherein the guiding skirt engages with the inlet in a sliding seal.

79. The method according to any one of claims 42 to 78, wherein the fluid passage is unsealed during a first movement of the valve member towards the second valve position, and the valve skirt or its second fluid passage is unsealed during a second further movement of the valve member towards the second valve position.

80. The method according to claims 42 to 79, wherein the valve member is balanced with respect to the inlet pressure and the outlet pressure.

81. A pressure reducing valve having an inlet port and an outlet port, comprising or including, a valve member located between the inlet port and the outlet port, the valve member being movable between an open position allowing fluid to flow between the ports and a closed position preventing fluid flow, the valve member being in fluid communication with the inlet port and the outlet port, a movable sensing mandrel in fluid communication with the inlet pressure and a reference pressure, the sensing mandrel having a first position and a second position, the sensing mandrel acting on the valve member towards the second position to move the valve member away from its sealed position, the valve member being in any position other than its sealed position causing a fluid connection between the inlet and the outlet.

82. A pressure reducing valve as described herein with reference to any one or more of the accompanying drawings.

83. A method of operating a pressure reducing valve as described herein with reference to any one or more of the accompanying drawings.

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