Controlled closing system for hydraulic valves

Abstract

A valve (10) having a controlled closure system includes a housing (20) having an inlet port (22), a liquid outlet port (26), and an inlet chamber (40). A pressure responsive closure mechanism (34) is disposed between the inlet port (22) and the liquid outlet port (26). A control chamber (46) is in fluid communication with the inlet chamber (40) via a fluid passage (54, 64). The fluid passage (54, 64) includes a controlled closure system for controlling opening and closing of the fluid passage (54, 64). The controlled closure system includes a seal (60) movable relative to an opening (62) of the fluid passage (54, 64) and sealably abutting against the opening (62).

Description

TECHNICAL FIELD

[0001] The present invention relates generally to hydraulic valves, and more particularly to a controlled closing system for a hydraulic valve, such as a liquid drain valve. BACKGROUND

[0002] European Patent 3,039,326 assigned to the assignee of the present invention disclosed below describes a liquid drain valve configured for high flow and high pressure liquid discharge. Reference is made to FIG. 1A and FIG. 1B to describe the valve.

[0003] In FIG. 1A , the liquid drain valve 10 includes a housing 20 having an inlet port 22 couplable to a liquid line 24 (shown in phantom) and a liquid outlet port 26 extending from the housing and couplable to return any liquid flushed therethrough to the liquid system, or to drain elsewhere.

[0004] The inlet chamber 40 includes a pressure responsive closing mechanism 34 disposed between the inlet port 22 and the liquid outlet port 26. The closing mechanism 34 is configured to selectively open a liquid flow path 38 between the inlet port 22 and the liquid outlet port 26. A control chamber 46 is in fluid communication with the inlet chamber 40 via a restricted fluid passage 54. In the prior art, the fluid passage 54 is always open.

[0005] A pneumatic valve 48 is in fluid communication with the control chamber 46. A drain pilot valve 50 is in fluid communication with the control chamber 46.

[0006] The closing mechanism 34 is normally disposed in its closed position to prevent liquid flow from the inlet port 22 to the liquid outlet port 26. The pneumatic valve 48 is configured in its closed position to prevent liquid flow through the fluid outlet port 99. Upon a reduction in pressure within the control chamber 46, the closing mechanism 34 shifts to its open position thereby allowing liquid to flow along the flow path 38 between the inlet port 22 and the liquid outlet port 26.

[0007] The pressure responsive closing mechanism 34 includes a plunger assembly 70 axially displaceable between an uppermost open position and a lowermost closed position. The always open fluid passage 54 extends through the plunger assembly 70 of the closing mechanism 34. A rolling diaphragm 74 is clamped at one end 76 thereof to the plunger assembly 70 and at the other end 78 thereof to a portion fixed within an inner wall of the housing. The diaphragm 74 is a flexible sealing member and divides the housing into the inlet chamber 40 and the control chamber 46.

[0008] A liquid bleed port 86 can extend between the control chamber 46 and the inlet chamber 40 to allow liquid to bleed from the control chamber 46 to the liquid line 24.

[0009] The pneumatic valve 48 includes a housing 90 fixedly coupled to the housing 20, and a fluid inlet 92 extending into and in fluid communication with the control chamber 46.

[0010] The housing 90 has a fluid flow orifice 96 in communication with an outlet 99 and a valve seat formed in the housing 90 and defining the orifice 96. A flexible closure membrane 100 is fixed at one end 102 to the housing 90 and at a second end 104 to a float member 108 disposed within the housing 90. The float member 108 is axially movable under buoyant pressure between a lower, open position and an upper, closed position. In the closed position, the closure membrane 100 is pressed against the valve seat to seal the orifice 96.

[0011] The flow orifice 96 can have a first outlet orifice 96A that is substantially elongated slit-like, and can be in communication at one end thereof with a second outlet orifice 96B that is substantially larger in area than the first orifice 96A.

[0012] Displacement of the float member 108 from the closed position to the open position progressively separates successive straight transverse portions of the closure membrane 100, initially from the first outlet orifice 96A and subsequently from the second outlet orifice 96B, while displacement of the float member 108 from the open position to the closed position allows the closure membrane 100 to become sealingly biased against the outlet orifice and seal the valve seat. At the bottom end of the float member 108, there is a one-way valve 112 in the form of a sealing disc configured for bearing against a sealing shoulder of the fluid inlet 92 to seal against it; this prevents fluid from entering the control chamber 46 when the pneumatic valve 48 is in its open position.

[0013] The bleed pilot valve 50 is coupled to the housing 20 by an inlet port 118. An inlet fluid flow path 120 extends into the control chamber 46. The cross-sectional area (Al) of the inlet fluid flow path 120 is greater than the cross-sectional area (A2) of the restricted fluid passage 54. The bleed pilot valve 50 is configured with a bleed port 124 and a sealing shoulder 126 disposed between the inlet port 118 and the bleed port 124. A sealing plunger 128 is configured at one end thereof with a sealing member 130 configured to bear against the annular sealing shoulder 126 in a sealing manner, the opposite end of the plunger 128 being biased by a compression spring 134. Thus, the plunger is displaceable between a normally closed position in which the sealing member 130 sealingly bears against the sealing shoulder 126, and an open position in which the sealing member 130 is disengaged from the sealing shoulder 126 to release pressure from the control chamber 46.

[0014] Thus, the bleed pilot valve 50 is a pressure relief valve configured to open at a predetermined pressure threshold. The pressure threshold can be controlled by manually controlling the compression force of the compression spring 134, said manual control being by rotating the cap 140 (or FIG. 2 to FIG. 6from the spring to achieve tensioning or release.

[0015] FIG. 1B Another form of liquid drain valve 10 is shown. In this form, the drain pilot valve 250 has a tube 347 that is coupled to the inlet 22 at the coupling port 223 and to the control chamber of the drain pilot valve 250 at an additional port 345.

[0016] In this arrangement, the inlet 22 and the control chamber of the drain pilot valve 250 are at the same pressure. This eliminates or substantially reduces hammering, providing stable operation of the drain pilot valve 250. SUMMARY

[0017] The present invention seeks to provide an improved controlled closure system for a hydraulic valve, such as a liquid drain valve, as described in more detail below. The controlled closure system will be described with reference to a valve of the type shown in FIG. 1A or FIG. 1B The controlled closure system is described with reference to a valve of the type shown, but the invention is not limited to this type of valve.

[0018] There is thus provided in accordance with an embodiment of the present invention a valve having a controlled closure system, the valve comprising: a housing having an inlet port, a liquid outlet port, an inlet chamber, a pressure responsive closure mechanism disposed between the inlet port and the liquid outlet port and configured for selectively opening a liquid flow path therebetween, a control chamber in fluid communication with the inlet chamber via a fluid passage, a pneumatic valve in fluid communication with the control chamber and with an outlet orifice, wherein the closure mechanism is configured to be displaced into an open position to allow liquid to flow along the flow path between the inlet port and the liquid outlet port; and wherein the fluid passage comprises a controlled closure system for controlling opening and closing of the fluid passage, the controlled closure system comprising a seal movable relative to an opening of the fluid passage and sealable to the opening. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present invention will be more fully understood and appreciated by

[0020] FIG. 1A and FIG. 1B is a simplified cross-sectional view of a prior art liquid drain valve as described in European Patent 3039326;

[0021] FIG. 2 to FIG. 6 is a simplified cross-sectional view of a controlled closure system for a hydraulic valve, a liquid drain valve, constructed and operative in accordance with a non-limiting embodiment of the present invention, wherein:

[0022] In FIG. 2In this system, the movable seal of the shut-off system does not seal the fluid passage between the valve's inlet chamber and control chamber. The plunger assembly of the pressure-responsive shut-off mechanism seals the valve's inlet, and the floating member of the pneumatic valve does not compress the diaphragm to seal the pneumatic valve's outlet orifice. This allows air entering the valve's inlet to rise and flow through the fluid passage between the inlet chamber and control chamber, through the floating member, and out of the pneumatic valve's outlet orifice to reach the external environment.

[0023] exist FIG. 3 In this system, the pressure in the inlet chamber is greater than atmospheric pressure, which is the pressure in the control chamber. This pressure difference causes the plunger assembly of the pressure response closing mechanism to rise and allows liquid (water) and gas (air) to enter the inlet. This causes the movable seal of the closing system to rise and seal the fluid passage between the valve's inlet chamber and the control chamber. It also causes the floating member of the pneumatic valve to press against the closing diaphragm to seal the outlet orifice of the pneumatic valve, so that the air entering the valve's inlet does not flow out of the pneumatic valve's outlet orifice and the fluid entering the inlet can flow out of the liquid outlet port.

[0024] exist FIG. 4 In the middle, fluid has entered the control chamber above the rolling diaphragm, making the pressure in the control chamber the same as the pressure in the inlet chamber; due to the difference in area, the pressure-response shut-off mechanism begins to descend. The movable seal of the shut-off system still seals the fluid passage between the valve's inlet chamber and the control chamber. This slows down the descent of the plunger assembly of the pressure-response shut-off mechanism;

[0025] exist FIG. 5 In the middle, the plunger assembly of the pressure-response shut-off mechanism has completed its descent and sealed the valve inlet; once fluid can no longer flow to the liquid outlet port, the seal immediately falls to open the fluid passage, and the valve prepares for air to enter the valve inlet and return. FIG. 2 The structure; and

[0026] exist FIG. 6 In the middle, after returning to FIG. 2 After the structure is constructed, the gas (air) entering the valve inlet creates a negative pressure in the control chamber, which causes the plunger assembly of the pressure-response closing mechanism to rise; this allows air to enter the outlet orifice of the pneumatic valve and into the rest of the valve, and discharges liquid from the valve to the liquid line or liquid outlet port. Detailed Implementation

[0027] Now refer to FIG. 2 This illustrates a controlled shut-off system for a hydraulic valve fluid discharge valve, constructed and operated according to a non-limiting embodiment of the invention. For ease of understanding, the following describes... FIG. 1A to FIG. 1B The valve 10 is described herein; the same elements are indicated by the same reference numerals. However, the invention is not limited to this valve, but can be implemented with other hydraulic valves.

[0028] In the prior art, the restricted fluid passage 54 is always open. In contrast to the prior art, in the present invention, the restricted fluid passage 54 is not always open. Instead, a controlled closure system is provided that controls the opening and closing of the fluid passage 54, as described below.

[0029] In one embodiment of the present invention, the controlled closure system includes a seal 60 that is movable relative to an opening 62 of the fluid passage 54 and that can seal the opening 62 of the fluid passage 54, the opening 62 facing the inlet 22. The opening 62 can be a lower opening of the fluid passage 54, or, alternatively, as in the illustrated embodiment, the opening 62 is at a lower end of a tube 64 that is installed in the existing fluid passage 54, such that the tube 64 becomes the fluid passage of the system of the present invention.

[0030] The seal 60 can be spherical as illustrated, or alternatively can be rectangular, oval, or other shape. The seal 60 is axially (up and down) free to move in a bore 66 of a seal housing 68. The seal 60 is preferably denser than the liquid entering the inlet port 22.

[0031] Reference is now made to FIG. 2 to FIG. 6 the operation of the system is described.

[0032] In FIG. 2 , the movable seal 60 does not seal the fluid passage (i.e., tube 64 or fluid passage 54) between the inlet chamber 40 and the control chamber 46. The plunger assembly 70 of the pressure responsive closure mechanism 34 seals the inlet port 22 of the valve 10. The float member 108 of the pneumatic valve 48 does not press against the closure membrane 100 to seal the outlet orifice 96 of the pneumatic valve 48, so that air entering the inlet port 22 of the valve 10 can rise and flow through (around) the seal 60, through the fluid passage 64 (or 54) between the inlet chamber 40 and the control chamber 46, through the float member 108, and out the outlet orifice 96 of the pneumatic valve 48 to the outside environment.

[0033] In FIG. 3 , the pressure in the inlet chamber 40 is greater than the atmospheric pressure, which is the pressure in the control chamber 46. This pressure differential causes the plunger assembly 70 of the pressure responsive closure mechanism 34 to rise and allow liquid (water) and gas (air) to enter the inlet 22, which causes the movable seal 60 of the closure system to rise and seal the fluid passage 64 (or 54) between the inlet chamber 40 and the control chamber 46 of the valve 10. This also causes the float member 108 of the pneumatic valve 48 to press against the closure membrane 100 to seal the outlet orifice 96 of the pneumatic valve 48, so that air entering the inlet 22 of the valve 10 does not flow out the outlet orifice 96 of the pneumatic valve 48, and fluid entering the inlet 22 can flow out the liquid outlet port 26.

[0034] In FIG. 4In this process, fluid has entered the control chamber 46 above the rolling diaphragm 74, causing the pressure in the control chamber 46 to be the same as the pressure in the inlet chamber 40. However, the area above the diaphragm 74 is larger than the area below the diaphragm 74. This area difference causes the plunger assembly 70 of the pressure-responsive shut-off mechanism 34 to descend. The movable seal 60 of the shut-off system still seals the fluid passage 64 (or 54) between the inlet chamber 40 and the control chamber 46 of the valve 10. This slows down the descent of the plunger assembly 70 of the pressure-responsive shut-off mechanism 34 compared to the prior art.

[0035] exist FIG. 5 In the middle, the plunger assembly 70 of the pressure-response shut-off mechanism 34 has completed its descent and sealed the inlet 22 of the valve 10. Once fluid can no longer flow to the liquid outlet port 26, the seal 60 immediately drops to open the fluid passage 64 (or 54), and the valve 10 is ready for air to enter the valve inlet 22 and return to the outlet. FIG. 2 The structure.

[0036] Therefore, the movable seal 60 of the shut-off system provides a slower and more controlled closure of the fluid passage between the inlet chamber 40 and the control chamber 46, and also provides an immediate response to the closure of the valve inlet 22 to return to the initial operating configuration.

[0037] exist FIG. 6 In the middle, returning to FIG. 2 After the configuration, the gas (air) entering the valve inlet 22 creates a negative pressure in the control chamber 46, which causes the plunger assembly 70 of the pressure-response shut-off mechanism 34 to rise. This causes air to enter the pneumatic valve outlet orifice 96 through the control chamber 46 to the rest of the valve, and discharges liquid from the valve to the liquid line or liquid outlet port 26.

Claims

1. A method of using a valve (10), said valve comprising: A housing (20) having an inlet port (22), a liquid outlet port (26), an inlet chamber (40), a pressure-responsive shut-off mechanism (34) disposed between the inlet port (22) and the liquid outlet port (26) and configured to selectively open a liquid flow path (38) therebetween, a control chamber (46) fluidly communicating with the inlet chamber (40) via fluid channels (54, 64), and a pneumatic valve (48) fluidly communicating with the control chamber (46) and with an outlet orifice (96), wherein the shut-off mechanism (34) is configured to shift to an open position to allow liquid to flow along the flow path (38) between the inlet port (22) and the liquid outlet port (26); and The fluid channels (54, 64) include a controlled shut-off system for controlling the opening and closing of the fluid channels (54, 64), the controlled shut-off system including a seal (60) that is movable relative to the opening (62) of the fluid channels (54, 64) and capable of sealing the opening; The method includes an operating mode in which the seal (60) does not seal the fluid passages (54, 64), the pressure-response shut-off mechanism (34) seals the inlet port (22), and the pneumatic valve (48) does not seal the outlet port (96), allowing gas entering the valve (10) through the inlet port (22) to rise and flow through the fluid passages (54, 64) through the seal (60) and out of the outlet port (96). The method includes another operating mode in which the pressure-response shut-off mechanism (34) seals the inlet port (22), and once fluid can no longer flow to the liquid outlet port (26), the seal (60) immediately descends to open the fluid passages (54, 64).

2. The method according to claim 1, wherein the method includes another operating mode, wherein, The pressure in the inlet chamber (40) is greater than the pressure in the control chamber (46), which causes the pressure-responsive shut-off mechanism (34) to rise and allow fluid to enter the inlet port (22), which causes the seal (60) to rise and seal the fluid passages (54, 64), and causes the pneumatic valve (48) to seal the outlet orifice (96), so that the gas entering the inlet port (22) does not flow out of the outlet orifice (96) and the fluid entering the inlet port (22) can flow out of the liquid outlet port (26).

3. The method according to claim 1, wherein the method includes another operating mode, wherein, The pressure in the control chamber (46) is greater than the pressure in the inlet chamber (40), which causes the pressure-responsive shut-off mechanism (34) to descend toward the inlet port (22), wherein the seal (60) seals the fluid passages (54, 64), thereby slowing the descent of the pressure-responsive shut-off mechanism (34).

4. The method according to claim 1, wherein the method includes another operating mode, wherein, A negative pressure exists in the control chamber (46), which causes the pressure-response shut-off mechanism (34) to rise and allow gas to enter the outlet orifice (96) and flow into the control chamber (46), and discharge liquid from the valve (10).

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