Patent Description:
Petroleum refining operations in which crude oil is processed frequently produce residual oils that have very little value. The value of residual oils can be increased using a process known as delayed coking. Residual oil, when processed in a delayed coker, is heated in a furnace to a temperature sufficient to cause destructive distillation in which a substantial portion of the residual oil is converted, or "cracked" to usable hydrocarbon products and the remainder yields a residual petroleum by-product which is pumped into a large vessel known as a coke drum.

The production of coke is a batch process. Each delayed coker unit usually contains more than one coke drum. In delayed coking, the feed material is typical residuum from vacuum distillation towers and frequently includes other heavy oils. The feed is heated as it is sent to one of the coke drums. The feed arrives at a coke drum with a temperature ranging from <NUM> to <NUM> (<NUM> to <NUM>°F). Typical drum overhead pressure ranges from <NUM> to <NUM> kPa (<NUM> to <NUM> PSIG). Coker feedstock is deposited as a hot liquid slurry in a coke drum. Under these conditions, cracking proceeds and lighter fractions produced flow out of the top of the coke drum and are sent to a fractionation tower where they are separated into vaporous and liquid products. A solid, residuum called coke is also produced and remains within the drum. When a coke drum is filled, residual oil from the furnace is diverted to another coke drum. When a coke drum is filled to the desired capacity, and after feedstock is diverted to another drum, steam is typically introduced into the drum to strip hydrocarbon vapors off of the solid material. The material remaining in the coke drum cools and is quenched. Solid coke forms as the drum cools and must be removed from the drum so that the drum can be reused. While coke is being cooled in one drum and while the cooled solid coke is being extracted from that drum, a second drum is employed to receive the continuous production of coke feedstock as a part of the delayed coker process. The use of multiple coke drums enables the refinery to operate the furnace and fractionating tower continuously. Drum switching frequency ranges from <NUM> to <NUM> hours.

In typical coking operations dramatic heat variances are experienced by elements in the coking operation. For example, a coke drum is filled with incoming byproduct at about <NUM> degrees Celsius (<NUM> degrees Fahrenheit) and subsequently cooled after being quenched to nearly ambient temperatures. Not surprisingly, this repetitive thermal cycling may create or cause significant problems including stark heat distributing variances throughout various components of a valve system. The heated residual byproduct utilized in coking operations comes into contact with not only the coke drum, but valve and seat components. This heating and subsequent cooling may result in expansion of various elements within a valve system. As previously mentioned the delayed coking process typically comprises at least two vessels so that while one is being filled the other is being purged of material and prepared to receive another batch of byproduct. Thus, during the off cycle, when a vessel is being purged of its contents it will cool and return to a state of equilibrium. It is this cyclical pattern of dispensing hot residual byproduct into a coke drum and subsequently cooling the byproduct that leads to thermal differential and stress within the coke drum, a valve, the valve parts or a line. It is this cyclical loading and unloading and stressing and un-stressing of a coke drum, valve or line that is referred to as thermal cycling. Thermal cycling typically results in the weakening or fatiguing of a coke drum, a valve and its parts which may lead to a reduction in the useful life of the components. Uneven heat distributions or thermal variants existing between various components of the seat system result in decreased longevity of the constitutive elements of the valve body.

Also, because coke is formed using pressure, the deheading valve must form a seal to allow the pressure to build within the coke drum. This seal is generally formed using tight tolerances between the components of the deheading valve such as between the seats and the blind. These tight tolerances, however, increase the force required to slide the blind between the seats to open and close the valve. Also, due to this pressure, it is common to pressurize the internal compartments of the deheading valve such as by providing steam to the internal compartment. If a deheading valve does not provide a good seal, large amounts of steam will escape which increases the total amount of steam required. In many cases, the cost of supplying steam to pressurize the valve can be significant.

<CIT> describes an isolation valve according to the preamble of claim <NUM> and having a sealing means for a gate valve including one-piece seat rings disposed on both sides of the gate. <CIT> discloses that a resilient O-ring is loosely received in an annular groove in the leading face of each seat ring. The seat rings are urged by spring pressure, augmented by fluid pressure, against the opposite sides of the gate to effect a seal between the seat ring and the gate.

<CIT> discloses a gate-type valve including separate seat ring and inner seat ring. The valve of <CIT> includes springs and hydraulic rams arranged to urge the seat ring and the inner seat ring against a surface of the gate.

Steam is critical to the coking process. Steam provides fluidization of coke particles in the reactor, but it also drives mechanical processes in the valve. Fluidized coke particles, material called process fluids, are dirty and can damage equipment used in the coking process. Traditional valves weld a seat plate to a seat to isolate the process fluid from the valve body. However, the coking process involves wide variations in temperatures and pressures in the reactor. The changing temperatures cause thermal expansion in the equipment, such as the gate. As the gate changes shape due to thermal expansion the seal between the seat and the gate is compromised so that it is unable to contain the high pressures, thus leaks form at the seat/gate interface, due to the increased rigidity. Thus a need exists for a seat plate which isolates the process fluid from the valve body and can still maintain the freedom of movement to articulate with gate deformation caused by thermal expansion.

Accordingly, there exists a need for an extended floating seat plate which articulates to improve the seal between the seat and the gate as the gate thermally expands and contracts during the thermal cycle and which can isolate the valve body from the valve opening to prevent process fluid from entering the valve body.

The general purpose of the systems and methods disclosed herein is to provide an improved seat plate or gate to isolate the seat and the valve body from the process fluids in the coke drum. Specifically, in some embodiments an isolation valve configured to isolate at least one port on a seat plate from a valve opening. In some embodiments the valve comprises a gate having a first side and a second side, a seat with an opening, a receiving portion configured to receive a gate and the gate configured to be selectively inserted into the receiving portion intermediate the seat. In some embodiments there is at least one port formed in the seat, a conical floating seat plate nested concentrically against the seat and between the seat and the opening wherein the seat plate is configured to isolate at least one port formed in the seat from the opening wherein the seat plate is further configured to articulate independent of the seat. According to the invention there is a bias system configured to bias the seat plate against the seat to isolate the seat from the opening.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present disclosure should be or are in any single embodiment of the invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment, but may refer to every embodiment.

One skilled in the relevant art will recognize that the invention, as defined by the claims, may be practiced without one or more of the specific features or advantages of a particular embodiment.

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.

In order to describe the manner in which the advantages and features of the invention 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 appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope as defined by the claims, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:.

The present embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the disclosed invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed descriptions of the embodiments of the apparatus, as represented in <FIG> are not intended to limit the scope of the invention, as claimed, but are merely representative of present embodiments of the invention.

In general, the figures disclose a floating seat plate that maintains constant contact and load against the gate to keep the sealing surfaces in the valve protected from process fluids. In some embodiments the sealing surface comprises the interface between the seat <NUM> and the gate <NUM>. In some embodiments the sealing surface comprises the surf ace between floating seat plate <NUM> and gate <NUM>. In some embodiments the floating seat plate comprises a dynamic seat function - Live-loaded with bias systems so the seat plate can follow surface changes in the gate surface as the gate heats and expands during stroking and high temperature changes. In some embodiments the floating seat plate maintains a positive barrier between body steam chamber and process fluid through port <NUM> by improving the seal between the seat and the seat plate. In some embodiments the steam chamber comprises a first side of bellows and is isolated from the process fluid. In some embodiments the seat plate is used to maintain constant contact with gate in all positions such that all process fluid is captured and isolated from the valve body chamber. In some embodiments the floating seat plate allows for axial seat travel upstream and downstream to balance sealing load on both sides of gate as the temperatures inside the drum, opening and through the bottom of the valve change. In some embodiments an axial hard stop on each seat allows the upstream seat to maintain sealing contact with gate.

In some embodiments an extended floating seat plate <NUM> extends on each side of the gate to prevent the process fluid from entering the body. In some embodiments the extended floating seat plates are dynamic and spring loaded by a caliper in the bottom of the valve which bias the floating seat plate against the seat. In some embodiments plates are further biased or loaded against the seat by a positive pressure steam charge in body cavity when in operation. In some embodiments a dual dynamic live-loaded seating provides bi-directional sealing such that the floating seat plate seals equally with high pressure from either flange end.

In some embodiments a bellows is seal welded to the two independent rings eliminating steam bypass between rings. In some embodiments the bellows if made of INCONEL® to prevent degradation or failure from the heating and cooling cycles. In some embodiments springs are used provides the initial sealing force to maintain seal at lower pressures. In some embodiments INCONEL® coil springs are used. In some embodiments a bellows effective area provides additional force under higher pressures to maintain sealing force required. In some embodiments a shoulder bolt assembly holds the seat assembly <NUM> together and sets the travel limits of the seat when valve is stroking to prevent over travel into the gate port.

In some embodiments a connection between the dynamic seat ring and the extended floating seat plate is formed to improve the seal between the seat ring and the floating seat plate. In some embodiments.

In the following description, numerous references will be made to processing equipment such as steam and drum structures, but these items are not shown in detail in the figures. However, it should be understood that one of ordinary skill in the art and in possession of this disclosure, would readily understand how the present disclosure how the structures can be incorporated.

Detailed references will now be made to the embodiments of the disclosed invention, examples of which are illustrated in <FIG> illustrate various views of a valve with a floating seat plate in accordance with one or more embodiments of the invention.

In the typical delayed coking process, petroleum residues are fed to one or more coke drums where they are thermally cracked into light products and a solid residue-petroleum coke. Several different physical structures of petroleum coke may be produced. To produce the coke, a delayed coker feed originates from the crude oil supplied to the refinery and travels through a series of process members and finally empties into one of the coke drums used to manufacture coke. A basic refinery flow diagram is presented as <FIG>, with two coke drums shown.

Due to the shape of the coke drum, coke accumulates in the area near and attaches to the flanges or other members used to close off the opening of the coke drum during the manufacturing process. To empty the drum, the flanges or members must first be removed or relocated. In the case of a flanged system, once full, the coke drum is vented to atmospheric pressure and the top flange is unbolted and removed to enable placement of a hydraulic coke cutting apparatus. Removing or opening the bottom flange, or valve is commonly known as "de-heading" because it removes or breaks free the head of coke that accumulates at the surface of the flange or valve. Once the flanges are removed, the coke is removed from the drum by drilling a pilot hole from top to bottom of the coke bed using high pressure water jets. Following this, the main body of coke left in the coke drum is cut into fragments which fall out the bottom and into a collection bin, such as a bin on a rail cart, etc. The coke is then dewatered, crushed and sent to coke storage or a loading facility.

Although the present disclosure may be utilized in association with both top and bottom de-heading systems, or rather the de-heading system independent valve actuator system of the disclosed invention may be applicable and utilized on both the top and bottom openings of a coke drum, the following detailed description and preferred embodiments will be discussed in reference to a bottom de-heading system only. One ordinarily skilled in the art will recognize that the invention as explained and described herein for a coke drum bottom de-heading system may also be designed and used as a coke drum top de-heading system.

The present disclosure describes a valve system and method for unheading or de-heading a coke drum following the manufacture of coke therein. As the disclosed invention is especially adapted to be used in the coking process, the following discussion will relate specifically in this manufacturing area. It is foreseeable however, that the disclosed invention may be adapted to be an integral part of other manufacturing processes producing various elements or by products other than coke, and such processes should thus be considered within the scope of this application. For example, it is contemplated that the disclosed invention de-header system and de-header valves may be utilized within other critical service applications, such as inlet feed line isolation, blowdown isolation, fractionator isolation, and back warming.

<FIG> depicts, generally, a petroleum manufacturing and refinery process <NUM> having several elements and systems present (identified, but not discussed). In addition to these elements, petroleum manufacturing and refinery process <NUM> further comprises at least one coke drum and may include, as illustrated, a first and a second coke drum <NUM> and <NUM>, respectively, and de-header valves <NUM>-a and <NUM>-b attached thereto. In typical delayed coking operations, there are at least two coke drums in simultaneous operation so as to permit the ongoing, batch continuous, manufacture and refinery of petroleum as well as its coke byproduct.

<FIG> illustrates a non-limiting example of a de-heading system <NUM>. Coke drum de-heading system <NUM> comprises a de-header valve <NUM> that removably couples to a coke drum <NUM> using various means known in the art. De-header valve <NUM> typically couples to coke drum <NUM> or a spool at its flanged port or opening, much the same way a flanged head unit would be attached in prior related designs. De-header valve <NUM> is shown further attaching to upper and lower bonnets <NUM> and <NUM>, respectively.

The seat system of the de-header valve is designed to cleanly break the bond between the coke and the exposed surface of the valve closure at each stroke. The total thrust required for this action combined with the thrust required to overcome seating friction and inertia is carefully calculated and is accomplished by actuating the valve closure, thus causing it to relocate or transition from a closed to an open position.

<FIG> illustrates a non-limiting example of a sliding blind gate-type de-header valve <NUM>, according to one exemplary embodiment of the disclosed invention. Sliding blind gate-type de-header valve <NUM> comprises a main body <NUM> removably coupled to upper and lower bonnets <NUM> and <NUM>, each comprising upper and lower chambers <NUM> and <NUM>, respectively. Main body <NUM> comprises an opening or port <NUM> therein. Main body <NUM> removably couples to a complimentary flange portion and associated opening or port of a coke drum <NUM> or a spool, such that each opening is concentric and aligned with one another.

Sliding blind gate-type de-header valve <NUM> further comprises a valve closure in the form of a sliding blind or gate <NUM>. Some embodiments of a gate <NUM> may have an aperture therein that is capable of aligning with the opening in the coke drum and/or the opening in the spool, as well as the opening in the main body of the valve <NUM>. Alternatively, some gates may be solid, not utilizing an aperture therein, but rather utilizing a short gate that effectively opens the valve to allow coke from a coke drum <NUM> to fall through a valve when the shortened gate <NUM> is retracted into the upper bonnet <NUM>.

The gate <NUM> slides back and forth in a linear, bi-directional manner between means for supporting a valve closure, shown in this exemplary embodiment as seat support system <NUM>. Seat support system <NUM> may comprise any type of seating arrangement, including dual, independent seats, wherein the seats are both static, both floating or dynamic, or a combination of these. Seat support system <NUM> may alternatively comprise a single seat in support of valve closure <NUM>, wherein the seat may comprise a static or floating or dynamic seat. In another exemplary embodiment, means for supporting a valve closure may dispense with a seating system in favor of a support system built into main body <NUM>, such that one or more portions or components of main body <NUM> are selected and prepared to support valve closure <NUM>. In any event, seat support system may comprise a metal contact surface that contacts and seals with a metal surface on valve closure <NUM>, wherein this contact seal is maintained during the coke manufacturing process.

Valve closure <NUM> is coupled to clevis <NUM>, which is turn coupled to valve stem <NUM>. Valve stem <NUM> may be utilized as an element of a system that functions to cause valve closure <NUM> to oscillate between an open and closed position. An actuator system <NUM> may be a hydraulically controlled power source contained within cylinder and that is capable of moving valve closure <NUM> through its linear, bi-directional cycle during a coking process, and may be utilized to de-head and re-head the coke drum <NUM>. Alternatively, an actuator system <NUM> may be an electrically controlled power source utilizing an electric actuator <NUM> that is capable of moving a valve closure via a transmission system <NUM> through its linear, bi-directional cycle during a coking process, and may be utilized to dehead and rehead the coke drum.

Detailed references will now be made to the preferred embodiments of the disclosed invention, examples of which are illustrated in <FIG> illustrate various views of a torque isolating valve actuator in accordance with one or more embodiments of the invention. In some embodiments coke drum deheading system <NUM> is disclosed wherein a valve <NUM> comprising an actuator housing <NUM>, an upper bonnet <NUM> and lower bonnet <NUM>. In some embodiments the actuator housing <NUM> may be a hollow housing configured to house other components. In some embodiments the actuator housing <NUM> may enclose interior components. In some embodiments the actuator housing <NUM> may partially enclose internal components. In some embodiments the actuator housing <NUM> may comprise an internal lubricant pooled in the actuator housing <NUM> and circulated around internal components to reduce friction caused by movement of internal components. In some embodiments the actuator housing <NUM> may be rigid and configured to provide structural support to internal components, as well as brace against a torque moment created during actuation by the operation of internal components. In some embodiments the internal components housed in the actuator housing <NUM> are internally lubricated, and the actuator housing <NUM> may have access ports which are not sealed. In some embodiments the actuator housing <NUM> may a power port <NUM> to power the actuator mechanism which may be powered pneumatically, electrically or mechanically.

In some embodiments the actuator housing <NUM> houses a nut housing <NUM> disposed within the actuator housing. In some embodiments the nut housing comprises an actuator end proximal an actuator <NUM> and a stem end, on the opposite end of the nut housing <NUM>, disposed adjacent the stem <NUM>. In some embodiments the actuator comprises an actuator motor <NUM> disposed on the actuator end of the nut housing <NUM>. In some embodiments the actuator motor <NUM> is pneumatically powered. In some embodiments the actuator motor <NUM> is electrically powered. In some embodiments the actuator <NUM> is manually driven. In some embodiments the actuator housing <NUM> comprises a channel <NUM> through which an indicator indicates the position of the nut housing. In so embodiments the indicator channel <NUM> indicates the position of the gate in its stroke. In some embodiments the indicator channel <NUM> will indicate to an operator whether the gate is open, partially open or closed. In some embodiments the actuator is configured to move the stem <NUM> bidirectionally through the valve <NUM> to cause a gate or blind <NUM> to move to an open or a closed direction.

Referring now to <FIG> which discloses a floating seat plate configured to isolate process fluid from entering the valve body. In some embodiments separating the seat <NUM> from the floating seat plate <NUM> improves and simplifies manufacturing by requiring the smaller floating seat plate be ground flat instead of the combined seat plate <NUM> and seat <NUM>. In some embodiments the floating seat plate <NUM> improves the distribution of loads on the seat <NUM> created during delayed coker process. The improved load distribution is accomplished in part by the isolation of the seat plate <NUM> from the seat <NUM>. During coke processing the material is heated to its cracking temperature (approximately <NUM>°F (<NUM>)) and is placed under pressure in a drum. The heat causes the equipment, including the seat <NUM>, gate <NUM> and the floating seat plate <NUM> to thermally expand and change shape. In addition, the pressurized drum challenges the seal between the seat <NUM>, gate <NUM> and seat plate <NUM>. In some embodiments the floating seat plate <NUM> isolates the pressure on the seat <NUM> so as to allow fewer leaks because the seat is not influenced by the seat attachment. In addition, in some embodiments the at least partially independent movement by the floating seat plate <NUM> allows the seat <NUM> to partially isolate the pressures inside the drum body from impacting the seat, making the seat <NUM> pressure more uniform. Finally, separating the seat <NUM> and the floating seat plate <NUM> provides greater control and ability to manipulate the force between the floating seat plate <NUM> and the seat <NUM> using the spring rates so that the seal is fully loaded by the seat.

In some embodiments the floating seat plate improves the seal between the seat plate <NUM> and the seat <NUM> and the seal between the seat plate <NUM> and the gate <NUM>, particularly as the gate thermally expands and deforms. In some embodiments the seat plate 23is self-leveling against the gate and comprises a ball/cone and socket configuration to allow articulation by the seat. In some embodiments the cone and socket configuration is provided by the angled shelf <NUM> and packing <NUM> at the interface between the seat plate <NUM> and the seat <NUM>. As the gate <NUM> or seat <NUM> thermally expand and change shape, the floating seat plate <NUM> is able to articulate and maintain a seal independent of the orientation of the seat <NUM>. In some embodiments the spring <NUM> presses the seat <NUM> against the gate <NUM> while a bellows <NUM> is activated by internal pressuring from the steam port <NUM> to expand the bellows <NUM> and assist the springs <NUM> to apply more load on the gate <NUM> to seal the drum for the delayed coking process. Shoulder bolts <NUM> hold the assembly <NUM> together and set travel limits for the floating seat plate <NUM>.

In some embodiments the valve comprises a fist port <NUM>. In some embodiments the valve comprises a plurality of ports <NUM>. In some embodiments ports <NUM> are in fluid communication with the valve body so that steam can transport from the valve body through ports <NUM> to steam chambers <NUM> comprise channels formed in the seat assembly <NUM>. In some embodiments the operation of the floating seat plate <NUM> protects the ports <NUM> from process fluid in the body and which passes through the opening <NUM> as the drum is emptied. In some embodiments two seat plate directly abut seats <NUM> and gate <NUM> and prevent process fluid from entering the gate port <NUM>. In some embodiments the valve comprises lower bonnet plates <NUM> configured to receive the gate <NUM> when it is placed in the closed position. In some embodiments the lower bonnet plates <NUM> isolate the valve body <NUM> from the process fluid which may migrate with the gate <NUM> as it is moved from a first position to a second position. In some embodiments the floating seat plate <NUM> protects the port <NUM> at all times from the inside of the bonnet <NUM>, <NUM> so when the gate <NUM> hole opens the opening <NUM> and prevent exposure of the ports <NUM> or the inside of the valve to the process fluid.

In some embodiments an isolation valve <NUM> is configured to isolate a valve body from the process fluid passing through the valve opening <NUM>. In some embodiments a seat <NUM> has a receiving portion that is configured to receive a gate. In some embodiments the receiving portion is in the middle of the seat <NUM> body. In some embodiments the seat comprises a seat assembly <NUM> with a seat assembly <NUM> disposed on opposite sides of a gate <NUM> having a first side <NUM> and a second side <NUM> and aligned so as 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 <NUM>. In some placed two separate seats which are disposed adjacent the gate <NUM>, with a first seat <NUM> adjacent fist side <NUM> of the gate <NUM> and a second seat <NUM> placed adjacent the second side <NUM> of the gate <NUM>. In some embodiments the gate <NUM> is configured to be selectively positioned intermediate a first seat and a second seat.

In some embodiments the seat assembly <NUM> comprises a floating seat plate <NUM>. In some embodiments the floating seat plate <NUM> is nested inside the inner circumference of the seat <NUM> so as to abut the seat <NUM>. In some embodiments the floating seat plate <NUM> is concentrically nested between the seat <NUM> and a valve opening <NUM> without being attached to the seat <NUM>. In some embodiments the seat plate <NUM> is configured to articulate independent of the seat <NUM>, to accommodate gate <NUM> deformations due to thermal expansion or thermal differentials created by greater heat being applied to one location over on the surface of the gate <NUM> such as when the heat is applied to the gate's first side <NUM> and not equally applied to the gate's second side <NUM>. In addition, in some embodiments the floating seat plate <NUM> comprises degrees of motion to accommodate different pressures formed inside the coking drum during the coking process.

In some embodiments the seat assembly <NUM> comprises a sealing system <NUM> which improves the seal between the seat plate <NUM>, the seat <NUM>. In some embodiments the sealing system <NUM> comprises a bias system that selectively seals the seat plate <NUM> and the seat <NUM> that biases the seat plate <NUM> against the seat <NUM>. In some embodiments the sealing system <NUM> comprises mechanical shapes and packing members <NUM> which are integrated at the interface between the seat and the seat plate.

In some embodiments the bias system <NUM> of claim <NUM> further comprises a first bias member <NUM>. In some embodiments the bias system comprises a first bias member <NUM> and a second bias <NUM>. In some embodiments the bias system comprises a first bias member <NUM>, a second bias member <NUM>, and a third bias member <NUM>. In some embodiments the bias member comprises a spring <NUM>. In some embodiments the bias member comprises a bellows <NUM>. In some embodiments the bias member comprises a steam chamber <NUM>. In some embodiments the bias system <NUM> comprises any combination of bias members which function cooperatively to bias the floating seat plate <NUM> against the seat <NUM>. In some embodiments the bias system functions to bias the floating seat plate <NUM> against the gate <NUM>. In some embodiments the bias system comprises a plurality of bias members configured to bias the floating seat plate <NUM> against a first side of the gate <NUM> and to bias the floating seat plate <NUM> against the second side of the gate <NUM>. In some embodiments the bias system <NUM> further comprises a third bias member positioned on the second side <NUM> of the gate configured to bias the seat plate <NUM> against the seat <NUM> in a direction of the gate configured to seal the seat plate <NUM> and the seat <NUM> against both the first side <NUM> and the second side <NUM> of the gate. In some embodiments the bias system comprises as bias assembly <NUM> limited in travel by a shoulder bolt <NUM>.

In some embodiments the bias system <NUM> comprising a combination of cooperatively operating bias members improves the seal to meet American Petroleum Institute ("API") standards. In some embodiments the floating seat plate <NUM> is ground flat and positioned in the center of the gate <NUM>. In some embodiments the seat plate <NUM> is biased against the seat using springs creating a force of nearly 1379kPa (200PSI). In some embodiments, in addition to biasing the seat plate <NUM>, the springs give the seat plate <NUM> degrees of freedom and allows the seat plate <NUM> to move and adjust to the so to maintain constant contact with the gate <NUM> and allows the seat plate <NUM> to remain in mutual contact with the gate <NUM> through the thermal cycle. In some embodiments the port <NUM> further comprises a steam chamber which can be selectively pressurized to expand the chamber and further bias the seat plate <NUM>. The bellows <NUM> is welded <NUM> to a first packing <NUM>, which in some embodiments is a seat plate <NUM>, and a retainer <NUM>. In some embodiments bellows <NUM> is welded <NUM> to the seat plate <NUM> and a packing <NUM> so as to seal the steam in the steam chamber <NUM>. In some embodiments, as the steam pressure is increased the steam chamber <NUM> expands the bellows <NUM> expands and the seat plate <NUM> is further biased against the seat <NUM> and the gate <NUM> to improve the seal between the gate <NUM> the seat <NUM> and the seat plate <NUM>. In some embodiments the bias system creates a cumulative cooperative force sufficient to meet or exceed the API standards of <NUM> kPa (<NUM> PSI).

In some embodiments the seat plate <NUM> comprises a shelf <NUM> which interfaces with the seat <NUM>. In some embodiments the shelf <NUM> is angled to give the seat a conical shape as it mates with the seat <NUM>. In some embodiments packing <NUM> is inserted into the seat-seat plate interface <NUM> and upon activation the angled shoulder <NUM> is pressed into the seat <NUM> at the interface <NUM> and energizes packing <NUM> by changing the shape of the packing <NUM>. In some embodiments biasing the seat plate <NUM> against the seat <NUM> deforms the packing <NUM>. In some embodiments, when gate <NUM> deforms by thermal expansion during the heating cycle, the floating seat plate <NUM> articulates its position to maintain the seal between the seat <NUM> and the seat plate <NUM> and the gate <NUM> and the seat plate <NUM>. In some embodiments floating seat plate <NUM> adjusts to the changing surface dimensions of the gate <NUM> as the gate <NUM> repositions from an open position to a closed position or a closed position to an open position. In some embodiments the packing <NUM> may be comprise a square cross section with dimensions that are approximately the same as the interface <NUM>. In some embodiments the packing <NUM> will be slightly larger than the shape of the interface <NUM>. In some embodiments packing <NUM> will comprise a segment of packing <NUM> that can be used as packing <NUM> or packing <NUM> in a deheading valve in accordance with one or more embodiments of the present invention. As shown, packing <NUM> includes a woven outer sheath <NUM> (where 901a-901d identify various unwound strands of the sheath). Woven outer sheath <NUM> comprises expanded graphite with an oxidation resistant additive. Packing <NUM> also includes a woven wire mesh core <NUM>. In packing <NUM>, woven wire mesh core <NUM> is comprised of multiple woven Strands (as indicated by the multiple arrows). Each of the woven strands comprises an Inconel® or Monel® (or similar type) alloy. In other embodiments, a single (larger) woven Strand may be used as woven wire mesh core <NUM>. Also, in some embodiments, a single strand of packing <NUM> can be used for packing <NUM>. In other embodiments, two or more stands of packing <NUM> can be used for packing <NUM>.

In some embodiments packing <NUM> provides the conically shaped floating seat plate <NUM> with freedom of movement to articulate with gate <NUM> thermal expansion as the valve moves through the thermal cycle. In some embodiments the packing <NUM> improves the seal between the seat <NUM> and the floating seat plate <NUM> even as the seat plate <NUM> repositions in response to gate <NUM> shape changes. In some embodiments the floating seat plate <NUM> maintains a radially biased force against the packing <NUM> and seat <NUM> and the gate <NUM> even as the shape of the gate <NUM> changes. In some embodiments the floating seat plate <NUM> maintains a radially biased force against the packing <NUM> and the seat <NUM> and the gate <NUM> even as body pressure vectors in the coking drum change direction and magnitude and exert direction-specific forces against the seat <NUM>. In some embodiments the seat plate <NUM> and packing <NUM> isolate the seat <NUM> from pressure in the body during processing.

In some embodiments packing <NUM> allows the floating seat plate <NUM> end-to-end movements so gate <NUM> and floating seat plate <NUM> and seat <NUM> touch simultaneously. In some embodiments the packing <NUM> does not necessarily seal the interface between the seat plate <NUM> and the seat <NUM>, but instead provides for axial movement so the seat plate <NUM> can become mutual with the seat <NUM>. Thus in some embodiments as the gate <NUM> deforms under thermal expansion the seat plate <NUM> can reposition independent of the seat <NUM> to improve the contact, and thus the seal between the seat plate <NUM> and the gate <NUM>.

In some embodiments in addition to being welded <NUM> to the seat plate <NUM> to isolate steam, bellows <NUM> is cooperatively biased with the seat plate to enhance and improve the sealing force between the seat plate <NUM>, the seat <NUM> and the gate <NUM>. The bellows <NUM> is welded <NUM> to the seat plate assembly <NUM> to isolate a steam chamber <NUM>. In some embodiments bellows <NUM> isolates the steam chamber, port <NUM> and valve body from process in the chute comprising valve opening <NUM> through which process passes as drum is emptied. In some embodiments the bellows <NUM> is configured to flex as steam pressure is applied to increase the bias force of the seat plate assembly <NUM> against the gate <NUM>. In some embodiments the bellows <NUM> is made from materials which can be welded. In some embodiments bellows <NUM> comprises INCONEL®, a nickel chromium-based superalloy or a nickel alloy (e.g. a Monel® alloy). In some embodiments bellows <NUM> are configured with a single spring fold <NUM>, while in some embodiments bellows <NUM> is configured with multiple sprig folds <NUM>, the number of folds is determined by the force required and the amount of desired movement. In some embodiments bellows <NUM> comprises bellows tabs which overlap with adjacent structures. In some embodiments bellows tabs provide a welding surface <NUM> wherein the bellows tab is welded <NUM> to the adjacent structure. In some embodiments the adjacent structure comprises the floating seat plate <NUM>. In some embodiments a bellows tab is welded <NUM> to a packing <NUM>. In some embodiments, the steam chamber <NUM> is configured on the surface of the bellows <NUM> which faces away from the central opening <NUM>, while in some embodiments the steam chamber <NUM> is against the bellows surface <NUM> which faces towards the central opening <NUM>. In some embodiments steam enters steam chamber <NUM> through port <NUM>, increasing volume of the steam chamber <NUM>. In some embodiments the chamber <NUM> volume increase and the steam cooperatively biases other bias members such as spring <NUM> and bellows <NUM> to increase the bias force seat plate <NUM> places against the seat <NUM> and the bias force the seat plate <NUM> exerts against the gate <NUM> and the force the seat <NUM> places against the gate <NUM>. In some embodiments bellows <NUM> is a solid sheet of material that is folded and compressed to maintain a bias.

The weld <NUM> may be formed by any suitable technique including but not limited to electric arc, laser welding, TIG and electron welding to name a few examples. This weld <NUM> ensures a fluid tight joint or seal between the bellows <NUM> and the packing <NUM> so that fluid flow in the valve opening <NUM> is restricted to between the first and second ports <NUM>, <NUM> and also that process fluid does not enter into the upper bonnet <NUM> and lower bonnet <NUM> actuator <NUM> or escape to the outside environment.

In some embodiments the valve is configured to continuously force steam through the port <NUM> and steam chamber <NUM>. In some embodiments positive steam pressure in the body is maintained and configured to continually force steam out of the steam body and into the valve opening <NUM> to prevent process from entering the steam chamber <NUM>, the port <NUM>, or the valve body <NUM>. In some embodiments the seat plate <NUM> maintains constant contact and load against the gate <NUM> to keep sealing surfaces <NUM> protected. In some embodiments the seat plate <NUM> is an extended seat plate <NUM> that maintains constant contact with the gate <NUM> in all positions through the gate stroke such that all process is captured and not allowed to enter the body chamber <NUM>.

In some embodiments packing <NUM>, <NUM> changes shape as floating seat plate <NUM> presses on packing <NUM> and radially compresses the packing <NUM> to improve the seal between the seat plate <NUM> and the seat <NUM>. In some embodiments packing <NUM> cushions the floating seat plate <NUM> seat <NUM> interface <NUM> to permit seat plate <NUM> to maintain its degrees of freedom under bias, thus even as the gate <NUM> thermally expands under the heat and pressure of the heat cycle, the floating seat plate <NUM> "floats" or articulates to maintain the seal between the seat plate <NUM> the seat <NUM> and the gate <NUM> in a ball/cone and socket manner. In some embodiments the valve comprises two floating seat plates <NUM> to allow for sufficient axial seat travel upstream and downstream in the opening <NUM> to balance the sealing load on both sides of the gate <NUM>. In some embodiments the shoulder bolt <NUM> acts as an axial hard stop on each seat on each side of the gate <NUM> allowing the upstream seat <NUM> to maintain its sealing contact with the gate <NUM>. A retainer.

In some embodiments the extended seat plates <NUM> on each side of the gate <NUM> prevent the process from entering the body as the valve closes the gate port and exposes the process into the body, typically on other through conduit slab gate valves. In some embodiments extended seat plate 23are dynamic and spring loaded by the caliper in the bottom of the valve. In some embodiments seat plate <NUM> are further loaded or biased by a positive pressure steam charge in body cavity <NUM> when in operation. In some embodiments floating seat plate <NUM> extends <NUM> beyond the seat <NUM>. In some embodiments floating seat plate <NUM> is configured to maintain constant contact with the gate such that all process fluid is isolated from the seat <NUM> and prevented from entering the valve body.

In some embodiments the valve may comprise a sealing system <NUM> which seals the valve closed to maintain a minimum pressure inside the coke drum. In some embodiments the sealing system <NUM> comprises a steam chamber <NUM> which is isolated from the drum. In some embodiments the sealing system <NUM> further comprises packing <NUM> configured to improve the seal between the seat plate <NUM> and the seat <NUM>. In some embodiments the sealing system <NUM> comprises the dual dynamic live-loaded floating seating plates which provide bi-directional sealing that seals equally with high pressure from either flange end of the opening <NUM>. In some embodiments the sealing system <NUM> comprises ICONEL® bellows <NUM> which are seal welded <NUM> to a first independent packing <NUM>. In some embodiments bellows <NUM> is welded <NUM> to a retainer <NUM>. In some embodiments bellows <NUM> is welded to both first and a retainer <NUM>, eliminating steam bypass between rings. In some embodiments the bellows <NUM> acts as both a seal to isolate the opening <NUM> from the valve body <NUM>, and a bias system <NUM> to bias the seat plate <NUM> against the seat <NUM> and the gate <NUM>. In some embodiments the sealing system further comprises coil springs <NUM>. In some embodiments the coil springs <NUM> are INCONEL® or some other super alloy and which provides the initial sealing force to maintain seal at lower pressures without the additional bias force created by steam. In some embodiments the sealing system <NUM> further comprises shoulder bolts <NUM>. In some embodiments shoulder bolt <NUM> is configured to help hold the seat assembly <NUM> together. In some embodiments shoulder bolt <NUM> is configured to set the travel limits of the seat assembly <NUM> when the valve is stroking. In some embodiments shoulder bolt <NUM> is configured to prevent seat assembly <NUM> over travel into the gate port opening <NUM>. Shield <NUM> shields the seat assembly from the flow-through.

Some embodiments comprise ports <NUM>, <NUM> which provides fluid communication between the valve body <NUM> and the steam chamber <NUM>. In some embodiments steam passes from the valve body <NUM> through one or both ports <NUM> or <NUM> and into the steam chamber <NUM> to bias the floating seat plate <NUM> against the gate <NUM> and seat <NUM>. Some embodiments comprise ports <NUM>, <NUM> formed in the seat <NUM> at the interface <NUM> between the seat <NUM> and the seat plate <NUM> and a conical seat plate <NUM> comprising an angled shelf <NUM> which is configured to create a radial force into the seat <NUM> when the seat plate <NUM> is biased against the seat <NUM>. In some embodiments the port <NUM> further comprises packing <NUM> configured to improve the seal between the seat <NUM> and the seat plate <NUM>. In some embodiments packing <NUM> comprises graphite, fiber glass, SPECTRA® fibers or carbon nanofibers, carbon nanotubes, extruded nanotubes or another appropriate material.

In some embodiments isolation valve <NUM> configured to isolate at least one port <NUM> on a seat plate <NUM> from a valve opening <NUM> comprises a gate having a fist side <NUM> and a second side <NUM>; a seat <NUM> further comprising: an opening <NUM>; a receiving portion <NUM> configured to receive a gate, the gate configured to be selectively inserted into the receiving portion <NUM> intermediate the seat <NUM>; at least one port <NUM> formed in the seat <NUM>; a conical seat plate <NUM> nested concentrically against the seat <NUM> and between the seat <NUM> and the opening <NUM> wherein the seat plate <NUM> is configured to isolate at least one port <NUM> formed in the seat <NUM> from the opening <NUM> wherein the seat plate <NUM> if further configured to articulate independent of the seat <NUM>; and a bias system <NUM> configured to bias the seat plate <NUM> against the seat <NUM> to isolate the seat <NUM> from the opening <NUM>. In some embodiments the isolation valve <NUM> further comprises packing <NUM> placed at the interface <NUM> between the conical seat plate <NUM> and the seat <NUM> which packing member <NUM> deforms as it is compressed radially as the seat plate <NUM> is biased against the seat <NUM>. In some embodiments the conical seat plate <NUM> comprises a shelf <NUM> with an angled surface which interface <NUM> with the seat <NUM> and is configured to radially compress the packing <NUM> as the bias system <NUM> is activated. In some embodiments the isolation valve <NUM> bias system <NUM> comprises a spring <NUM>, a bellows <NUM> and a steam chamber <NUM> configured to cooperatively work to expand the steam chamber <NUM> and bias the seat plate <NUM> and seat <NUM> against the gate <NUM> when steam pressure is applied to the steam chamber <NUM>.

Some embodiments teach a method of isolating a steam port <NUM> in an decoking valve from the valve opening <NUM> comprising: providing a gate having a fist side <NUM> and a second side <NUM>; providing a seat <NUM> comprising an opening <NUM>; a receiving portion <NUM> configured to receive a gate, the gate configured to be selectively inserted into the receiving portion <NUM> intermediate the seat <NUM>; at least one port <NUM> formed in the seat <NUM>; a conical seat plate <NUM> nested concentrically against the seat <NUM> and between the seat <NUM> and the opening <NUM> wherein the seat plate <NUM> is configured to isolate at least one port <NUM> formed in the seat <NUM> from the opening <NUM> wherein the seat plate <NUM> if further configured to articulate independent of the seat <NUM>; biasing the seat plate <NUM> against the seat <NUM> using a bias system <NUM>; and compressing a packing member <NUM> placed at the interface <NUM> between the conical seat plate <NUM> and the seat <NUM> to substantially isolate the at least one port <NUM> from the opening <NUM>.

In some embodiments the method further comprises providing an angled shelf <NUM> on the seat plate <NUM> which shelf <NUM> interface <NUM> with the seat <NUM> to radially compress the seat <NUM> as the seat plate <NUM> is biased against the seat <NUM>. In some embodiments the method further comprises providing packing <NUM> at the shelf <NUM> - seat <NUM> interface <NUM> wherein the packing <NUM> is configured to be compressed radially upon activation of a bias force against the seat plate <NUM>.

In some embodiments the method further comprises selectively biasing the seat plate <NUM> against the seat <NUM> by pressurizing the steam chamber <NUM> with steam. In some embodiments the method further comprises isolating the valve body from process fluid with a seat plate <NUM> which extends beyond the seat <NUM> so that the seat plate <NUM> scrapes against the seat as the gate moves. Some embodiments perform the steps to the method in a different order, delay performing steps, or eliminate steps all together.

Claim 1:
An isolation valve (<NUM>) configured to isolate a valve body from process fluid passing through the valve comprising:
a seat (<NUM>) configured to receive a gate (<NUM>), the gate (<NUM>) having a first side and a second side, the gate (<NUM>) configured to be selectively positioned intermediate the seat (<NUM>);
a seat plate (<NUM>) configured to articulate independent of the seat (<NUM>), the seat plate (<NUM>) comprising a sealing system (<NUM>) which selectively seals the seat plate (<NUM>) and the seat (<NUM>); and
a bias system (<NUM>) that biases the seat plate (<NUM>) against the seat (<NUM>),
characterized in that the seat plate (<NUM>) is concentrically nested between the seat (<NUM>) and a valve opening (<NUM>) such that the seat plate (<NUM>) is nested inside an inner circumference of the seat (<NUM>), and there is an angled shelf (<NUM>) on the seat plate (<NUM>) which interfaces with the seat (<NUM>) to radially compress the seat (<NUM>) when the seat plate (<NUM>) is biased against the seat (<NUM>).