Isolation Valve Liquid Purge System

Abstract

A system and method for purging an isolation valve using a liquid purge medium.

Description

[Technical Field]

[0001] This disclosure relates generally to purging isolation valves, and more particularly to using hydrocarbons distilled in a fractionation column as a liquid purge medium in isolation valves. [Background technology]

[0002] Isolation valves control the flow of potentially harmful process fluids. To prevent the fluid from leaving the line and entering the valve body or hood, a positively pressurized purge medium ensures that the process fluid does not leave the line. Gases such as water vapor or nitrogen are often used as purge media. Summary of the Invention [Problem to be solved by the invention]

[0003] However, purging with gas that leaks into the process can contaminate the process and need to be removed later during processing. It can also change the chemistry and density of the process fluid, leading to cavitation in slurry pumps and harming other downstream equipment. [Means for solving the problem]

[0004] A general objective of the systems and methods disclosed herein is to improve the purging of isolation valves. Specifically, in some embodiments where multiple distillation columns or fractionators and slurry pump systems are present in a refinery, each fractionator has a circuit isolated by multiple isolation valves. The invention includes an isolation valve purge system for the isolation valves, the internal components of which are configured to isolate process fluid streams. In some embodiments, the isolation valves are purged using a liquid purge medium produced in the fractionator, such as hydrocarbons, oils of various viscosities, or a combination of hydrocarbons.

[0005] References to features, advantages, or similar language throughout this specification do not imply that all of the features and advantages that may be realized by the present disclosure must be or are present in any single embodiment of the invention. Instead, language referring to features and advantages is understood to mean that the particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, discussions of features and advantages and similar language throughout this specification may, but do not necessarily, refer to the same embodiment, and may refer to all embodiments.

[0006] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. Those skilled in the art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in particular embodiments that may not be present in all embodiments of the invention.

[0007] The features and advantages of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.

[0008] In order to explain the manner in which the advantages and features of the present disclosure can be obtained, a more particular description of the invention, briefly described above, will be rendered by reference to specific embodiments thereof which are illustrated in the accompanying drawings, with the understanding that the drawings depict only typical embodiments of the invention and therefore should not be considered as limiting its scope, the invention will be described and explained with additional specificity and detail through the use of the following accompanying drawings, in which: [Brief explanation of the drawings]

[0009] [Figure 1] FIG. [Figure 2A]10A-10C illustrate exemplary operations and identify several possible positions of an isolation valve according to some embodiments. [Figure 2B] 10A-10C illustrate exemplary operations and identify several possible positions of an isolation valve according to some embodiments. [Figure 2C] 10A-10C illustrate exemplary operations and identify several possible positions of an isolation valve according to some embodiments. [Figure 3A] 1A-1C are cutaway views of some embodiments of an isolation valve in a closed position. [Figure 3B] 1A-1C are cutaway views of some embodiments of an isolation valve in a closed position. [Figure 3C] 1A-1C are cutaway views of some embodiments of an isolation valve in a closed position. [Figure 3D] 1A-1C are cutaway views of some embodiments of an isolation valve in a closed position. [Figure 4] 1A-1C are cutaway views of some embodiments of an isolation valve in an open position. [Figure 5] 1 is a diagram of an isolation valve in a partially open or throttled position according to some embodiments. [Figure 6] FIG. 10 is a detailed cutaway view of the sealing assembly, biasing assembly, and liquid chamber. [Figure 7] FIG. 10 is a cross-sectional view of the floating seat assembly together with the liquid purge chamber. [Figure 8] FIG. 10 is a cross-sectional view of a biasing assembly together with a liquid purge chamber. [Figure 9] FIG. 10 is a cross-sectional view of a valve seat together with a liquid purge chamber. [Figure 10] FIG. 10 is an alternative cross-sectional view of the valve seat together with the liquid purge chamber. [Figure 11] FIG. 10 is an alternative cross-sectional view of the valve seat together with the liquid purge chamber. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present embodiments of the present disclosure are best understood by reference to the drawings, wherein like parts are designated with like numerals throughout. It will be readily understood that the components of the disclosed invention, as generally described and illustrated herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the device embodiments, as depicted in Figures 3A-11, is not intended to limit the scope of the invention as claimed, but is merely representative of the present embodiments of the invention.

[0011] In some embodiments, the refinery or plant uses refinery-produced purge media, such as hydrocarbons distilled in a fractionator, to purge isolation valves. In some embodiments, the fractionator distills the crude feed into its constituent parts: heavy coker oil (HCO), medium coker oil (MCO), and light coker oil (LCO), as well as other fuels and gases, and a bottoms product oil from the main fractionator, called slurry oil. In some embodiments, a portion of the slurry oil is recycled back to the main fractionator above the entry point of the hot reaction product vapors to cool and partially condense the reaction product vapors as they enter the main fractionator. The flow of this slurry oil in the slurry circuit is controlled by isolation valves. Because slurry oil is the oil most likely to leave deposits inside the valves and damage them, in some embodiments, the HCO, MCO, LCO, or a combination of these oils is maintained under a positive pressure greater than the line pressurization pressure to purge the isolation valves. When used as a purging medium, small amounts of oil will enter the process fluid through imperfect seals between metal-to-metal surfaces within the valve, but because the liquid slurry is composed of similar or identical hydrocarbons as the process fluid, the leaked oil does not contaminate the slurry.

[0012] Substituting a liquid hydrocarbon for the slurry instead of a gas prevents cavitation within the pump, which can occur when gas enters the process fluid. In prior art circuits, gas leaking past the valve seat can cause rapid pressure changes within the process fluid, leading to the formation of small, vapor-filled cavities where the pressure is relatively low. Cavitation is undesirable for the pump and can, in some cases, damage it. Using a liquid instead of a gas as the purge medium avoids these problems.

[0013] Reference will now be made in detail to embodiments of the disclosed invention, examples of which are illustrated in Figures 3A-11, which show various views of valves having liquid medium purge ports in accordance with one or more embodiments of the present invention.

[0014] <General description of the refining process> Refinery processes such as delayed coking and fluid catalytic cracking, as well as other refining processes, can involve extreme pressures and temperatures. Isolation valves used in refinery plants contain internal components that maintain the valve seal through extreme temperatures and pressures.

[0015] Several purification processes are illustrated in Figures 2A-2C, which show an exemplary purification operation and highlight the various lines utilized to transport materials, including gases, liquids, and solids, from one location to another throughout the operation. The schematic flow diagram of a typical current unit in Figure 2A is based on a "side-by-side" configuration.

[0016] The bottoms product oil from the main fractionator contains residual coke particles that were not completely removed by the process. For this reason, the bottoms product oil is called slurry oil. A portion of the slurry oil is recycled back to the main fractionator above the entry point of the hot reaction product vapors, thereby cooling and partially condensing the reaction product vapors as they enter the main fractionator. The remainder of the slurry oil is passed to a slurry settler. The bottoms oil from the slurry settler contains the majority of the slurry oil coke particles and is recycled back to the coking feedstock.

[0017] In particular, Figures 2B-2C illustrate some of the locations where various embodiments of the isolation valve of the present invention may be utilized. Some embodiments of the valve 14 may be connected to any line or slurry circuit. In some embodiments, hydrocarbons from the coker are routed to the isolation valve's functional space, such as the bonnet, under a higher positive pressure than the process medium, such as the slurry, which is under positive pressure to prevent the process medium from entering the valve housing. In some embodiments where a hydrocarbon purge medium is used to purge the isolation valve of the slurry circuit, the purified hydrocarbon purge medium is mixed with the process medium and then returned to the fractionation column for distillation.

[0018] Fractionation towers and isolation valves, also known as distillation columns or fractionators, are used throughout refineries and chemical plants. Fractionation towers distill chemical mixtures into their component parts, or fractions, based on differences in volatility. Fractionation towers often have outlets spaced along the column so that multiple products, each with a different boiling point range, can be removed from the column distilling the multi-component feed stream. The "lightest" product, with the lowest boiling point, exits the top of the column, and the "heaviest" product, with the highest boiling point, exits the bottom.

[0019] Delayed coking is one of the most major conversion processes used in petroleum refineries. It is widely used to convert the high-boiling, high-molecular-weight hydrocarbon fractions of petroleum crude oil into more valuable gasoline, olefin gases, and other products. Cracking of petroleum hydrocarbons uses thermal cracking because it produces more gasoline with a higher octane value. It also produces by-product gases with more carbon-carbon double bonds (i.e., more olefins) and therefore higher economic value.

[0020] The bottoms product oil from the main fractionator contains residual coke particles. For this reason, it is called slurry oil. A portion of the slurry oil is passed to a slurry settler. The bottoms oil from the slurry settler contains the majority of the slurry oil catalyst particles and is recycled back to the catalyst riser by combining with the coking feedstock oil. Clarified slurry oil or decant oil is removed from the top of the slurry settler for use elsewhere in the refinery, as a heavy oil blend component, as carbon black feedstock, or in some cases, the slurry oil is pumped through the bottoms circuit for use in heat recovery or steam generation using the slurry bottoms circuit.

[0021] Isolation valves are used in fluid processing systems to stop the flow of process media at a given location. They may also be used to provide flow logic (select one flow path or another) and to connect external equipment to the system. Valves are classified as isolation valves because of their intended function in the system, not the type of valve itself. Therefore, many different types of valves can be classified as isolation valves. An isolation valve must be able to effectively stop the passage of fluid. Gate valves, ball valves, plug valves, globe valves, and butterfly valves can be considered to provide a tight and effective shutoff when the valve trim or internal mechanism creates the required seal.

[0022] <Isolation valve embodiment> The present disclosure may be utilized in conjunction with isolation valves such as those described in U.S. Patent Application Nos. 12 / 848,013 and 16 / 403,039, which are incorporated herein by reference. The present invention may be utilized with any isolation valve used in a delayed coker in a bottoms slurry circuit, such as that shown in Figures 2B-2C. Those skilled in the art will recognize that the use of fractionator hydrocarbons as a purge medium for the isolation valves of the present invention as described and illustrated in the present invention may be designed and used for other systems.

[0023] This disclosure describes a valve purge media system and method for purging isolation valves, such as those used in bottoms slurry circuits. The system and method may be used in inlet feed line isolation, fractionator isolation, and other critical maintenance applications such as back warming.

[0024] The present invention may be utilized to control the flow of process media and materials, including slurry fluids, any fluid, solid, and / or gas, at any point in the operation of an isolation valve to prevent them from entering the valve trim, e.g., bonnet, actuator, seat, seal, etc., and interfering with proper operation. Additionally, those skilled in the art will recognize that the valves illustrated and described in this invention may be designed and used in other environments where it is desirable to control the movement of materials, including fluids, solids, and / or gases.

[0025] Examples of isolation valves and associated internal trim are shown in Figures 3-11. This specification describes a valve system and method for isolating the flow of material within a line. The present invention is particularly adapted for isolation valves used to isolate bottoms slurry circuits. However, it is contemplated that the present invention may be adapted as an integral part of other manufacturing processes for producing various components, and therefore such processes should be considered within the scope of this application. Before describing the details of the present invention, it should be noted that the systems and methods of the present invention are designed to have or possess significant functional, usability, and safety advantages over prior related designs and systems.

[0026] Some embodiments of the valve system may include a seat system to isolate the flow of slurry oil through the line from the bottom of the fractionation tower.

[0027] Some embodiments include: a) a valve coupled to a line, which may be an outlet slurry oil line, and to the seat system during operation of the coker; and b) structure for actuating the valve closure.

[0028] Some embodiments may include at least one bonnet. Some embodiments may include upper and lower bonnets coupled to the body, which may be removed to replace valve components without disconnecting the body from the line. Some embodiments may include one or more plates located inside the bonnet, which plates have planar surfaces that may contact one or more surfaces on the blind.

[0029] Some embodiments of the system may be constructed to isolate gases and hot liquids, particularly those utilized in delayed coking operations. Some embodiments are constructed to provide the benefit of enabling reliable, long-term flow isolation without performance degradation. In some embodiments, maintaining high valve performance over time is enhanced by features of the present invention, including purging the valve with LCO, MCO, or HCO to maintain proper contact between the seat and blind, which serves to remove debris from the valve's internal components. In prior art systems, the possibility of coking or oil clogging required frequent rebuilds and therefore removal of the valve from the line.

[0030] In some embodiments, the system is configured to hydrocarbon purge the valve body, upper, and lower bonnets, each of which can be independently removed to replace valve components without disconnecting the body from the lines. Some embodiments of the bonnet 30 may include at least one plate 52 positioned opposite each other, allowing the blinds 4 to maintain surface contact with the plates. The positive pressure of the hydrocarbon purge, in conjunction with the plate / blind 4 / 52 system located within the bonnet 30, prevents materials such as slurry oil from escaping from the lines into the bonnet 30. Some embodiments therefore prevent exposure of the internal elements of the valve system 14 to materials traveling through the lines. As a result, the internal components of the valve system 14 can remain clean and free of debris and buildup.

[0031] In some embodiments, the structure supporting the valve closure portion 4, which includes a seat support system 50, is purged with a liquid purge medium. The seat support system 50 may include a seat arrangement or configuration depending on the type of valve. In some embodiments, the structure supporting the valve closure portion 4 includes a seat support system 50 including a first seat 58 and a second seat 60 on either side of the valve closure portion 4, and the first seat 58 and the second seat 60 may be independent of each other. In some embodiments, the first seat 58 and the second seat 60 may be pressurized seat cartridges. The first and second seats 58 and 60 may be static or dynamic in nature, one static and the other dynamic, both dynamic, or both static. Alternatively, the seat support system 50 may consist of a single seat located or disposed between the body 16 of the valve 14 and the valve closure portion 4. In this configuration, the single seat applies a continuous force to the valve closure throughout its oscillation. In a single seat system, the single seat may be dynamic or static, depending on the needs of the valve type and system specifications and any other contributing factors.

[0032] Embodiments of the valve system include a liquid purge system in which purified hydrocarbons from the fractionator are pumped to one or more isolation valves for use as a liquid purge medium in the isolation valves. In some embodiments, the liquid purge system may utilize a line that draws purified hydrocarbons from the fractionator to the bottoms slurry circuit isolation valves for use as the liquid purge medium. In some embodiments, the liquid purge medium is maintained at a positive pressure, or a pressure higher than the pressure in the line, thereby continuously pumping hydrocarbons into the line and preventing process media, such as slurry oil, from entering the valve seat, bonnet, or other internal components. Pressure in the purge fluid system is maintained by using a fluid at a higher pressure than the process fluid in the valve.

[0033] Some embodiments of the liquid purge medium system may include an internal gas / liquid containment system that provides or maintains isolation of fluids, including gases, within the system. The internal fluid containment system may include the metal-to-metal contact seals described herein as well as the unique component configuration present within the bonnet 30 of the valve 14. The liquid purge medium, maintained at a positive pressure, forces hydrocarbons through the metal-to-metal contact seals to the extent that the fluid can pass, preventing process fluid from passing in the reverse direction into the internal components of the valve.

[0034] In some embodiments, the pump that pumps the liquid purge medium to the isolation valve is turned off when the internal components, including the seat system 50, the seat and the blinds 4, are inspected, repaired, and / or replaced, etc., without taking the valve body 16 off-line.

[0035] In some embodiments, the valve system 14 includes a liquid-purged body, where a purge medium is maintained at a temperature that regulates the valve body temperature, which may be constructed to create a barrier against the migration of gases, fluids, and solids. The purge elements of such embodiments prevent migration of materials from the lines into the upper and lower hoods 30. Therefore, the internal components of some embodiments do not become clogged with coke deposits or buildup. Repairs and replacements of internal components are significantly reduced. Therefore, some embodiments of the valve operate reliably for extended periods without degradation in performance.

[0036] Some embodiments are mechanically constructed to cooperate with a liquid purge medium by vibrating while the valve gate 4 is maintained in a partially open or throttled position. In some embodiments, the internal components of the bonnet 30 prevent the accumulation of oil, coke, and debris inside the bonnet 30. Some embodiments place the liquid purge fluid under positive pressure so that the internal components of the valve system 14 are not exposed to slurry oil, coke, and / or other buildup while the valve 14 is maintained in a partially open position. For example, some embodiments of the valve system 14 utilize a liquid purge system that creates a positive pressure inside the bonnet 30 to force the contents of the lines to remain within the lines and prevent them from migrating into the internal components of the valve 14.

[0037] In some embodiments, there may be additional mechanical features that cooperate with the liquid purge medium to maintain the valve in a partially open position over extended periods of time without impairing valve performance. For example, in some embodiments, the seating system 50 maintains continuous contact with the gate 4. The continuous contact in some embodiments disrupts accumulated coke and / or other debris, preventing it from accumulating on the valve 14 itself and falling into various internal components of the valve system 14. Some embodiments utilize a system located within the bonnet 30 that maintains contact with the gate 4 of the valve 14 as the gate 4 moves through open and closed positions. In some embodiments, the bonnet 30, preferably the lower bonnet 34 of the valve 14, includes one or more plates 52 that face each other and are biased against a surface of the gate 4 present within the lower bonnet 34. In some embodiments, a spring 54 is wound and biased against the lower bonnet 34 to be located between the bonnet 30 and the plate 4. Thus, the spring system 56 in some embodiments presses a plate 56 located within the lower bonnet 34 against the surface of the gate 4. The liquid purge media, in conjunction with a plate system located within the bonnet system 30, prevents gas, fluid, or solid matter from migrating from the lines into the bonnet 30. Thus, the combination of the liquid purge media system and plate system prevents the contents of the lines from contacting the internal elements of the gate system 14.

[0038] Turning to a diagram of the invention and a more detailed analysis of some of the embodiments of the invention, Figure 1 depicts a schematic of an oil production and refinery process. Light fractions, steam, and gases are released from an on-line coke vessel through steam lines 2a and 2b.

[0039] 3A-3D depict embodiments of an isolation valve in an open position. In some embodiments, the depicted valve may be connected in one or more of the positions described above (see FIG. 2). Each of FIGS. 3A, 3B, 3C, and 3D shows a different embodiment of valve 14.

[0040] While the valve depicted in Figures 3-11 is one embodiment of an isolation valve, it is contemplated that the valve 14 may comprise a variety of valve types and a variety of different components. The seating system 50 (e.g., in some embodiments, a dual metal seating surface), underhood 36, and all internal components are completely protected and isolated from materials flowing through the line while the valve is in the fully open, fully closed (see Figure 4), or partially open (see Figure 5) positions. Preferably, the materials used to construct the sealing components are corrosion-resistant and designed for exceptionally high metal-to-metal cycle duty. The seals of the valve 14 are designed to cleanly break the bond between the coke and the exposed surfaces of the valve closure with each stroke, and the coke is prevented from entering the internal components by a liquid purge medium. The total thrust required for this action, combined with the thrust required to overcome seat friction and inertia, is carefully calculated and achieved by actuating the valve closure 4, thereby repositioning or transitioning the valve closure 4 from a closed position to an open position.

[0041] In some embodiments, a portion of the liquid slurry is returned to the delayed coking process to recover hydrocarbons from the liquid slurry. A liquid purge medium is used to purge any process fluids, such as the bottoms slurry, from the isolation valve to prevent them from entering the valve body or hood. In some embodiments, a check valve is used to maintain a pressure greater than 10 psi within the system. The use of a liquid purge medium provides additional benefits over traditional steam or nitrogen. First, the liquid purge medium is generated during the distillation process, whereas steam or nitrogen must be produced. The liquid slurry created in the downline is often pressurized during the process. Any portion of the hydrocarbon purge medium injected into the liquid slurry while purging the isolation valve can be returned to the fractionator 11 above the entry point of the hot reaction product vapor to cool and partially condense the reaction product vapor as it enters the coker fractionator. The remainder of the liquid slurry is passed through a slurry settler. The bottoms from the slurry settler contains the majority of the liquid slurry coke particles in the delayed coking process and is recycled back into the process.

[0042] FIG. 2A illustrates an exemplary operation, highlighting the various lines utilized to transport materials, including gases, liquids, and solids, from one location to another throughout the operation. In particular, FIG. 2A illustrates some of the locations where various embodiments of the isolation valves of the present invention may be utilized. Some embodiments of valve 14 may be connected to any line or coke drum. Examples of some of the locations where valve embodiments may be utilized include: water drain valve 70, overhead vapor valves 71A / 71B, blowdown isolation valves 72A / 72B, module isolation valve 79, backheat isolation valve 80, fractionator isolation valve 10, drum bypass isolation valve 78, heater charge pump discharge isolation valves 82A / 82B, inlet isolation valve 26, switch manifold isolation valve 73, preheat activation isolation valves 74A / 74B, quench water isolation valve 75, steam isolation valve 76, and pit drain isolation valves 77A / 77B.

[0043] 3A-3D depict an embodiment of the valve system 14 in a closed position. The depicted valve system 14 is configured to couple to a line or coke drum and to a flange. In some embodiments, the depicted valve may be connected to one or more of the above-described positions (see FIG. 2A) in a delayed coking unit operation. FIGS. 3A, 3B, 3C, and 3D each depict a different embodiment of the valve 14.

[0044] The valve depicted in Figures 3-11 is an embodiment of a valve of the present invention, however, it is contemplated that valve 14 may comprise a variety of valve types and a variety of different components.

[0045] 3-13 show various views of valve 14 according to various embodiments. The depicted valve 14 includes a body 16 coupled to an upper bonnet 33 and a lower bonnet 34, which include a lower chamber 35 and an upper chamber 36, respectively. Body 16 includes a first flange portion 40 having an opening or port 42 and a second flange portion 44 having an opening or port 46. Body 16 couples 26 to complementary flange portions and associated openings or ports of line 2 or coke drums 18 and 22 such that the openings are concentric and / or aligned with one another.

[0046] The depicted isolation valve 14 further comprises a valve closure portion in the form of a sliding blind or gate 4 having an aperture capable of aligning with openings 42 and 46 in the open position. The valve closure portion 4 slides linearly and bidirectionally back and forth between means for supporting the valve closure portion, shown in this exemplary embodiment as a seat support system 50. The seat support system 50 may comprise any type of seat configuration, including dual independent seats, both static, both dynamic, and combinations thereof. The seat support system 50 may alternatively comprise a single seat supporting the valve closure portion 4, which may consist of a static seat or a dynamic seat.

[0047] In one embodiment, a continuous contact seal is created between the valve closure portion 4 and the seat support system 50, and the created contact seal is never broken or breached and its integrity is always maintained during the sliding or rotation of the valve closure portion 4 back and forth relative to the line from an open position to a half-open position and finally to a closed position. This continuous contact seal is preferably a metal-to-metal contact seal that performs several functions and has several advantages, working cooperatively with the liquid purge medium described herein. For example, the contact seal creates or at least contributes to the isolation of the valve 14, providing an isolated environment where substances are not allowed to escape outside the sealed area and enter the bonnet 30 or other parts of the valve 14, areas outside the valve, or other areas. Various liquid purge and containment systems may function to regulate pressure within the isolation valve 14 to contain substances within designated areas and maintain valve isolation. As another example, the continuous contact seal may help keep various components of the isolation valve clean and free of product substances because such substances are not allowed to exceed the area purged by the liquid purge. As another example, a polishing and grinding effect occurs as a result of the load being applied to the valve closure portion 4, which results in tight tolerances between the valve closure portion 4 and the first and second seats, and as the valve closure portion rotates between the first and second seats 58, 60.

[0048] In some embodiments, the seat support system 50 includes first and second seats 58, 60, and the valve closure portion 4 may be made of metal, thereby providing what is also referred to as a metal-to-metal contact or metal-to-metal seal, or metal-to-metal seat, of the valve closure portion 4. The metal-to-metal seat improves the durability of the system because non-metallic components, such as vinyl or rubber, are not used to seal the seat to the valve closure portion 4. The metal-to-metal seat allows the system to achieve higher sealing consistency, while also providing extended wear resistance and durability. In addition, the metal-to-metal seal allows the system 14, and specifically the seals therein, to be fine-tuned as needed. Each metal-to-metal contact seal within the valve body can be supported.

[0049] When the valve closure portion 4 is actuated and rotated from the closed position to the open position, the contact seal that exists between the surface of the valve closure portion 4 and the surface of the means supporting the valve closure portion acts to break up or disrupt any produced coke that has accumulated on or near the surface of the valve closure portion 4.

[0050] Referring now to Figures 6-11, alternative valve embodiments, such as a floating seat plate configured to isolate process fluid from entering the valve body purged by the liquid purge medium, are disclosed. In some embodiments, separating the seat 23 from the floating seat plate 23 improves and simplifies manufacturing by requiring a smaller floating seat plate to be ground flat instead of the combined seat plate 23 and seat 23. In some embodiments, the floating seat plate 23 improves load distribution on the seat. Improved load distribution is achieved, in part, by isolating the seat plate 23 from the seat 23. Heat from processing causes the equipment, including the seat 23, gate 11, and floating seat plate 23, to thermally expand and change shape. Additionally, a pressurized drum counteracts the sealing of the seat 23, gate 11, and seat plate. In some embodiments, the floating seat plate 23 isolates pressure on the seat 23, reducing potential leaks. This is because the seat is not affected by its mounting. Leakage is further reduced by a liquid purge medium under positive pressure, preventing residual oil from entering between the seals. Additionally, in some embodiments, the at least partially independent movement of the floating seat plate allows the seat 23 to partially isolate the pressure inside the drum body from impacting the seat, resulting in more uniform pressure on the seat 23. Finally, separating the seat 23 from the floating seat plate 23 provides greater control and the ability to use a spring rate to control the force between the floating seat plate and the seat 23 so that the seal is fully loaded by the seat.

[0051] In some embodiments, a liquid purge medium combined with a floating seat plate improves the seal between the seat plate 23 and the seat 23, and between the seat plate and the gate 11, especially as the gate thermally expands and deforms. In some embodiments, the seat plate includes a ball / cone and socket configuration to automatically level with the gate and allow articulation with the seat. In some embodiments, the cone and socket configuration is provided by an angled ledge 195 and packing 180 at the interface between the seat plate 23 and the seat 23. As the gate 11 or seat 23 thermally expands and changes shape, the floating seat plate can articulate to maintain a seal regardless of the orientation of the seat 23. In some embodiments, a spring 165 presses the seat 23 against the gate 11, while a bellows 170 is actuated by internal pressure from the purge liquid 185, expanding the bellows 170 and helping the spring 165 apply more load against the gate. The gap between the seat and seat plate interface is filled with a liquid purge medium. The pressure created by the increased volume of purge liquid being pumped into chamber 175 on the valve side of the bellows increases the pressure already created by the bellows, improving the seal between seat plate 23 and gate 11. In some embodiments, the liquid purge medium is an incompressible fluid.

[0052] In some embodiments, the valve includes a first port 185. In some embodiments, the valve includes multiple internal chambers and ports 187. In some embodiments, port 187 is in fluid communication with the valve disc such that purge liquid can pass from the valve disc through port 187 to purge liquid chamber 175, which includes a channel formed in seat assembly 145. In some embodiments, the action of floating seat plate 23 and pressurized liquid purge medium protects port 185 from process fluid within the body and from process fluid within the body that passes through opening 20 when the drum is emptied. In some embodiments, two seat plates directly abut against seat 23 and gate 11, preventing process fluid from entering gate port 180. In some embodiments, the valve includes a lower bonnet plate 34 configured to receive gate 11 when in the closed position. In some embodiments, lower bonnet plate 34 isolates valve disc 14 from process fluid that may move with gate 11 when gate 11 is moved from the first position to the second position. In some embodiments, the floating seat plate protects the port 185 from the interior of the bonnet 30, 33 at all times, thus preventing the port 185 or the interior of the valve from being exposed to process fluid when the gate 11 opens the opening 20. The port and channel 185 extending through the valve and bonnet are sized to contain a liquid purge medium.

[0053] In some embodiments, the isolation valve 14 is configured to isolate the valve body from process fluid passing through the valve opening 20. In some embodiments, the seat 23 has a receiving portion configured to receive a gate. In some embodiments, the receiving portion is located in the middle of the body of the seat 23. In some embodiments, the seat includes a seat assembly 145 disposed on either side of a gate 11 having a first side 12 and a second side 13 and aligned to create an opening through which process fluid can selectively pass. In some embodiments, the two sides of the seat are bolted together to create a seal between the seat and the gate 11. In some locations, two separate seats are disposed adjacent to the gate 11, with the first seat 23 adjacent to the first side 12 of the gate 11 and the second seat 23 adjacent to the second side 13 of the gate 11. In some embodiments, the gate 11 is configured to be selectively positioned intermediate the first seat and the second seat.

[0054] In some embodiments, the seat assembly 145 comprises a floating seat plate. In some embodiments, the floating seat plate is nested inside the inner periphery of the seat 23 so as to abut against the seat 23. In some embodiments, the floating seat plate 23 is not attached to the seat 23 but is nested concentrically between the seat 23 and the valve opening 20. In some embodiments, the seat plate is configured to articulate independently of the seat 23 to accommodate deformation of the gate 11 due to thermal expansion or differential heat caused by applying more heat to one location on the surface of the gate 11, such as when heat is applied to the first side 12 of the gate and not equally to the second side 13 of the gate. Additionally, in some embodiments, the floating seat plate 23 has several degrees of movement to accommodate different pressures.

[0055] In some embodiments, the seat assembly 145 comprises a sealing system 155 that improves the seal between the seat plate 23 and the seat 23. In some embodiments, the sealing system 155 comprises a biasing system that selectively seals between the seat plate 23 and the seat 23 and biases the seat plate 23 against the seat 23. In some embodiments, the sealing system 155 comprises a mechanical feature and a packing member 180 that is integrated at the interface between the seat and the seat plate.

[0056] In some embodiments, bias system 160 of the present invention further comprises first bias member 165. In some embodiments, the bias system comprises first bias member 165 and second bias member 170. In some embodiments, the bias system comprises first bias member 165, second bias member 170, and third bias member 175. In some embodiments, the bias member comprises spring 165. In some embodiments, the bias member comprises bellows 170. In some embodiments, the bias member comprises purge fluid chamber 175. In some embodiments, bias system 160 comprises any combination of bias members functioning in cooperation to bias floating seat plate 23 against seat 23. In some embodiments, the bias system functions to bias floating seat plate 23 against gate 11. In some embodiments, the bias system comprises multiple bias members configured to bias floating seat plate 23 against a first side of gate 12 and bias floating seat plate 23 against a second side of gate 13. In some embodiments, the biasing system 160 further comprises a third biasing member disposed on the second side 13 of the gate, the third biasing member configured to bias the seat plate 23 against the seat 23 in the direction of the gate configured to seal the seat plate 23 and seat 23 against both the first side 12 and the second side 13 of the gate. In some embodiments, the biasing system comprises a biasing assembly 145 having travel limited by a shoulder bolt 199.

[0057] In some embodiments, a biasing system 160, consisting of a combination of cooperating biasing members, improves the seal to meet American Petroleum Institute (“API”) standards. In some embodiments, the floating seat plate 23 is ground flat and centered on the gate 11. In some embodiments, the seat plate 23 is biased against the seat using a spring to generate a force approaching 200 PSI. In some embodiments, in addition to biasing the seat plate 23, the spring provides the seat plate 23 with a degree of freedom, allowing it to move and adjust to maintain constant contact with the gate 11 and to remain in contact with the gate 11 through thermal cycling. In some embodiments, the port 185 further comprises a purge fluid chamber, which can be selectively pressurized to expand the chamber and further bias the seat plate 23. A purge medium is pumped into the purge fluid chamber and maintained under positive pressure to force the purge fluid through the seal and into the process fluid. Bellows 170 is welded 171 to a first packing 180, which in some embodiments is seat plate 23, and a retainer 173. In some embodiments, bellows 170 is welded 171 to seat plate 23 and packing 180 to seal purging liquid in purging liquid chamber 175. In some embodiments, as the volume of purging liquid increases, purging liquid chamber 175 expands, and bellows 170 expands, purging liquid is pumped into chamber 175, increasing the pressure and further biasing seat plate 23 against seat 23 and gate 11, improving the seal between gate 11, seat 23, and seat plate 23. In some embodiments, the biasing system creates a cumulative cooperative force sufficient to meet or exceed API standards.

[0058] In some embodiments, the seat plate 23 includes a ledge 195 that interfaces with the seat 23. In some embodiments, the ledge 195 is angled to give the seat a conical shape as it mates with the seat 23. In some embodiments, the packing 180 is inserted into the seat-seat plate interface 190, and when actuated, the angled shoulder 195 presses into the seat 23 at the interface 190, biasing the packing 180 by changing its shape. In some embodiments, the seat plate 23 deforms by biasing the packing 180 against the seat 23. In some embodiments, as the gate 11 deforms, the floating seat plate 23 articulates its position to maintain a seal between the seat 23 and the seat plate 23 and between the gate 11 and the seat plate 23. In some embodiments, the floating seat plate 23 adjusts to the changing surface dimensions of the gate 11 as the gate 11 changes position from an open position to a closed position or from a closed position to an open position. In some embodiments, the packing 180 may have a rectangular cross-section that is approximately the same size as the interface 190. In some embodiments, the packing 190 is slightly larger than the shape of the interface 190. In some embodiments, the packing 180 comprises a packing section.

[0059] In some embodiments, the packing 180 provides the conically shaped floating seat plate 23 with freedom to articulate with the thermal expansion of the gate 11 as the valve moves through thermal cycles. In some embodiments, sealing is improved by pumping a liquid purge medium into the valve body so that the liquid purge medium fills any gaps that may form in the seal. In some embodiments, the packing 180 further improves the seal between the seat 23 and the floating seat plate 23 even as the seat plate 23 changes position in response to changes in the shape of the gate 11. In some embodiments, the floating seat plate 23 maintains a radially biased force against the packing 180, seat 23, and gate 11 even as the shape of the gate 11 changes. In some embodiments, the floating seat plate 23 maintains a radially biased force against the packing 180, seat 23, and gate. In some embodiments, the seat plate 23 and packing 180 isolate the seat 23 from pressure within the body during processing.

[0060] In some embodiments, the packing 180 allows movement of the floating seat plate 23 from end to end such that the gate 11, the floating seat plate 23, and the seat 23 are in simultaneous contact. In some embodiments, the packing 180 does not necessarily seal the interface between the seat plate 23 and the seat 23, but instead allows axial movement such that the seat plate 23 can become common with the seat 23. Thus, in some embodiments, as the gate 11 thermally expands and deforms, the seat plate 23 can change position independently of the seat, improving the contact, and therefore the seal, between the seat plate 23 and the gate.

[0061] In some embodiments, in addition to being welded 171 to the seat plate 23 to isolate the purge liquid, the bellows 170 is cooperatively biased with the seat plate to strengthen and improve the sealing force between the seat plate 23, the seat 23, and the gate 11. The bellows 170 is welded 171 to the seat plate assembly 145 to isolate the purge liquid chamber 175. In some embodiments, the bellows 170 is configured to flex as the purge liquid volume increases, and the resulting pressure is applied to increase the biasing force of the seat plate assembly 145 against the gate 11. In some embodiments, the bellows 170 is made from a weldable material. In some embodiments, the bellows 170 is made from INCONEL®, a nickel-chromium based superalloy, or a nickel alloy (e.g., Monel® alloy). In some embodiments, bellows 170 is configured with a single spring fold 166, and in some embodiments, bellows 170 is configured with multiple spring folds 166, the number of folds depending on the force needed and the amount of travel desired. In some embodiments, bellows 170 includes a bellows tab that overlaps an adjacent structure. In some embodiments, the bellows tab provides a welding surface 171 where the bellows tab is welded 171 to the adjacent structure. In some embodiments, the adjacent structure includes floating seat plate 23. In some embodiments, the bellows tab is welded 171 to packing 180. In some embodiments, purge fluid chamber 175 is configured on a surface of bellows 170 facing away from central opening 20, and in some embodiments, purge fluid chamber 175 is adjacent to the bellows surface 175 facing toward central opening 175. In some embodiments, purge fluid enters purge fluid chamber 175 through port 185, increasing the volume of purge fluid chamber 175. In some embodiments, the volume of chamber 175 increases and the purge liquid cooperatively biases other biasing members such as spring 165 and bellows 170 to increase the biasing force that seat plate 23 exerts against seat 23, and the biasing force that seat plate 23 exerts against gate 11, and the force that seat 23 exerts against gate 11.In some embodiments, the bellows 170 is a rigid sheet of material that is folded and compressed to maintain a bias.

[0062] The weld 171 may be formed by any suitable technique, including, but not limited to, electric arc, laser welding, TIG, and electron welding, to name a few. This weld 62 ensures a fluid-tight joint or seal between the bellows 170 and the packing 180, restricting fluid flow within the valve opening 20 between the first and second ports 36, 38 and preventing process fluid from entering the upper and lower bonnets 30, 33 and the actuator 65 or escaping to the external environment.

[0063] In some embodiments, the valve is configured to continuously pass purge fluid through port 185 and purge fluid chamber 175. In some embodiments, the purge fluid is kept under positive pressure to prevent process fluid from entering the bonnet, purge fluid chamber 175, port 185, or disc 35, continuously forcing purge slurry out of the disc and into valve opening 20. In some embodiments, seat plate 180 maintains constant contact and load against gate 11 to keep sealing surface 25 protected. In some embodiments, purge fluid is forced at high pressure through purge fluid chamber 175, port 185, or disc 35 to purge these spaces of any fluid process that may be entering during the stroke. In some embodiments, seat plate 23 is an extended seat plate 197 that maintains constant contact with gate 11 at all positions throughout the gate stroke, ensuring that all process is trapped and not allowed to enter disc chamber 35.

[0064] In some embodiments, the packings 180, 185 change shape as the floating seat plate 23 presses against the packing 180, compressing it radially to improve the seal between the seat plate 23 and the seat 23. In some embodiments, the packing 180 cushions the interface 190 between the floating seat plate 180 and the seat 23, allowing the seat plate 180 to maintain its freedom under bias, so that as the gate 11 thermally expands under the heat and pressure of thermal cycling, the floating seat plate 180 "floats" or articulates to maintain the seal between the seat plate 180, the seat 23, and the gate 11 in a ball-and-cone-and-socket manner. In some embodiments, the valve includes two seat plates 180 to allow sufficient axial seat movement upstream and downstream within the opening 20 to balance the sealing load on either side of the gate 11. In some embodiments, shoulder bolt 199 acts as a strong axial stop against each seat on each side of gate 11, allowing upstream seat 23 to maintain its sealing contact with gate 11.

[0065] In some embodiments, extended seat plates 23 on each side of gate 11 prevent process from entering the main body when the valve closes the gate port, exposing the process to the main body, typically on other through-conduit slab gate valves. In some embodiments, extended seat plates 23 are dynamic and spring-loaded by a caliper at the base of the valve. In some embodiments, seat plates 23 are further loaded or biased by a charge of positive pressure purge fluid in valve body cavity 35 during operation. In some embodiments, purge fluid is taken from downstream where fluid is pressurized as part of a purification process. In some embodiments, unpressurized slurry fluid is taken in and pressurized by a hydraulic pump or other known device, which forces purge fluid into chamber 175 to supplement the force of the bellows and strengthen the seal between seat plates 23 and gate 11. In some embodiments, a floating seat plate 23 extends 197 beyond the seat 23. In some embodiments, the floating seat plate 23 is configured to maintain constant contact with the gate such that all process fluid is isolated from the seat 23 and prevented from entering the valve disc.

[0066] In some embodiments, the valve may include a sealing system 155 that seals the valve. In some embodiments, the sealing system 155 includes a purge fluid chamber 175. In some embodiments, the sealing system 155 further includes packing 180 configured to improve sealing between the seat plate 23 and the seat 23. In some embodiments, the sealing system 155 includes dual dynamic live-loaded floating seat plates that provide bidirectional sealing that seals equally against high pressures from either flange side of the opening 20.

[0067] Some embodiments include ports 185, 187 that provide fluid communication between the valve disc 35 and the purge liquid chamber 175. In some embodiments, purge liquid enters the purge liquid chamber 175 from the valve disc 35 through one or both ports 185 or 187, biasing the floating seat plate 23 against the gate 11 and seat 23. Some embodiments include ports 185, 187 formed in the seat 23 at the interface between the seat 23 and the seat plate 23, and a conical seat plate 23 with an angled ledge 195 configured to create a radial force in the seat 23 when the seat plate 23 is biased against the seat 23. In some embodiments, the port 187 further includes a packing 180 configured to improve the seal between the seat 23 and the seat plate 23. In some embodiments, the packing 180 is made of graphite, fiberglass, SPECTRA® fiber or carbon nanofiber, carbon nanotubes, extruded nanotubes, or other suitable material.

[0068] In some embodiments, the isolation valve 14 is configured to isolate at least one port 185 on a seat plate 23 from a valve opening 20, the isolation valve 14 comprising a gate having a first side 12 and a second side 13, the seat 23 comprising the opening 20 and a receiving portion 200 configured to receive the gate, the gate configured to be selectively inserted into the receiving portion 200 intermediate the seat 23; at least one port 185 formed in the seat 23; a conical seat plate 23 nested concentrically between the seat 23 and the opening 20 abutting the seat 23, the seat plate 23 configured to isolate the at least one port 185 formed in the seat 23 from the opening 20, the seat plate 23 further configured to articulate independently of the seat 23; and a biasing system 160 configured to bias the seat plate 23 against the seat 23 to isolate the seat 23 from the opening 20. In some embodiments, the isolation valve 14 further includes a packing 180 positioned at an interface 190 between the conical seat plate 23 and the seat 23, the packing member 180 deforming when the packing member 180 is compressed radially as the seat plate 23 is biased against the seat 23. In some embodiments, the conical seat plate 23 includes a ledge 195 with an angled surface at the interface 190 with the seat 23 and configured to radially compress the packing 180 when the biasing system 160 is activated. In some embodiments, the biasing system 160 of the isolation valve 14 includes a spring 165, a bellows 170, and a purge fluid chamber 175 configured to cooperate to expand the purge fluid chamber 175 and bias the seat plate 23 and the seat 23 against the gate 11 when the purge fluid volume in the purge fluid chamber 175 increases.

[0069] Some embodiments teach a method of isolating a purge liquid port from a valve opening 20, the method including providing a gate having a first side 12 and a second side 13, and providing a seat 23, the seat 23 including the opening 20 and a receiving portion 200 configured to receive the gate, the gate configured to be selectively inserted into the receiving portion 200 intermediate the seat 23, at least one port 185 formed in the seat 23, and a conical seat plate 202 nested concentrically between the seat 23 and the opening 20. and a seat plate (23) configured to isolate at least one port (185) formed in the seat (23) from the opening (20), the seat plate (23) further configured to articulate independently of the seat (23), the method further including biasing the seat plate (23) against the seat (23) using a biasing system (160) and compressing a packing member (180) located at an interface (190) between the conical seat plate (23) and the seat (23) to substantially isolate the at least one port (185) from the opening (20).

[0070] In some embodiments, the method further includes providing an angled ledge 195 on the seat plate 23, the ledge 195 providing an interface 190 with the seat 23 and radially compressing the seat 23 when the seat plate 23 is biased against the seat 23. In some embodiments, the method further includes providing a packing 180 at the interface 190 between the ledge 195 and the seat 23, the packing 180 configured to be radially compressed when a biasing force is applied against the seat plate 23.

[0071] In some embodiments, the method further includes selectively biasing the seat plate 23 against the seat 23 by pressurizing the purge fluid chamber 175 with purge fluid. In some embodiments, the method further includes isolating the valve plug from the process fluid with the seat plate 23 extending beyond the seat 23 such that the seat plate 23 rubs against the seat as the gate moves. Some embodiments perform the method steps in a different order, delay the performance of a step, or eliminate a step altogether.

[0072] Finally, it is to be understood that the embodiments of the present disclosure disclosed herein are illustrative of the principles of the present disclosure. Other modifications that may be employed are within the scope of the present disclosure. Thus, by way of example, and not of limitation, alternative configurations of the present disclosure may be utilized in accordance with the teachings herein. Accordingly, the present disclosure is not limited to that precisely as shown and described.

Claims

1. 1. An isolation valve liquid purge system comprising: the isolation valve liquid purge system, a gate configured to selectively move through the port; a functional space configured to selectively receive the gate; a seat configured to seal against the gate; an actuator configured to actuate the gate; an isolation valve including: a coker fractionator; a bottoms slurry circuit configured to withdraw purified hydrocarbons from the coker fractionator; a line between the bottom slurry circuit and a functional space within the isolation valve; Equipped with an isolation valve liquid purge system, wherein the line fluidly connects the coker fractionator and the functional space, the line configured to operate at a first pressure, and the port configured to operate at a second pressure.

2. 2. The isolation valve liquid purge system of claim 1, wherein the line is configured to deliver a liquid purge medium of LCO from the coker fractionator to the functional space.

3. 2. The isolation valve liquid purge system of claim 1, wherein the line is configured to deliver a liquid purge medium of MCO from the coker fractionator to the functional space.

4. 2. The isolation valve liquid purge system of claim 1, wherein the line is configured to deliver a HCO liquid purge medium from the coker fractionator to the functional space.

5. 1. A system for purging a coker fractionator in fluid communication with a shut-off valve using coker fractionator fluid as a liquid purge medium, comprising: The system comprises: the coker fractionator; the isolation valve having a functional volume therein and a port through which a process fluid flows at a first pressure; a line fluidly connecting a fractionation column of the coker fractionation unit with the functional space; Equipped with The system, wherein the line is configured to deliver the liquid purge medium from the coker fractionator to the functional space at a first pressure greater than a second pressure in the port.

6. The system of claim 2 , wherein the liquid purge medium is LCO.

7. The system of claim 3 , wherein the liquid purge medium is MCO.

8. 5. The system of claim 4, wherein the liquid purge medium is HCO.

9. 1. A shut-off valve liquid purge system comprising: the isolation valve liquid purge system, a process circuit configured to operate at a process pressure and to conduct a process fluid; an isolation valve including a functional space and further including a valve trim and an imperfect seal, the imperfect seal isolating the valve trim from the process fluid; a bottoms slurry circuit in fluid communication with the isolation valve, the bottoms slurry circuit operating at a bottoms slurry circuit pressure and configured to channel slurry oil from a fractional coker, the bottoms slurry circuit comprising, and at least a portion of, hydrocarbon oil; a line from the bottom slurry circuit to the functional space of the isolation valve; Equipped with the bottom slurry circuit is configured to maintain a pressure of the slurry oil above the process pressure; The isolation valve liquid purge system is configured such that the defective seal allows the hydrocarbon oil to leak from the functional space into the process fluid to purge the functional space of the isolation valve.

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