CN106122490B

CN106122490B - Low flow restriction shut-off valve with overflow shutoff

Info

Publication number: CN106122490B
Application number: CN201610298753.4A
Authority: CN
Inventors: J·M·迪亚兹
Original assignee: Emerson Process Management Regulator Technologies Inc
Current assignee: Emerson Process Management Regulator Technologies Inc
Priority date: 2015-05-07
Filing date: 2016-05-06
Publication date: 2020-01-03
Anticipated expiration: 2036-05-06
Also published as: CN205991181U; CN106122490A

Abstract

The present invention relates to process transmission or control systems, and more particularly, to a low flow restriction shutoff valve with an overflow shutoff function for a process transmission or control system. A shutoff valve for a fluid transfer or storage system, comprising: a valve body defining an inlet port, an outlet port, and a fluid flow passage extending between the inlet port and the outlet port; a valve seat disposed in the valve body adjacent the outlet port; a shaft at least partially disposed in the valve body; and a control assembly disposed in the valve body and operatively coupled to the shaft. The control assembly is movable between a closed position in which the control assembly sealingly engages the valve seat to seal the outlet port and an open position in which the control assembly is distal from the outlet port and substantially outside of the fluid flow passage such that the control assembly provides a minimum flow restriction to fluid flowing through the fluid flow passage.

Description

Low flow restriction shut-off valve with overflow shutoff

Technical Field

The present disclosure relates to process transmission or control systems and, more particularly, to a low flow restriction shutoff valve with an overflow shutoff function for a process transmission or control system.

Background

Gas storage and distribution systems, such as systems for storing and distributing liquefied natural gas or liquefied petroleum gas, typically store gas from a producer in one or more tanks and then transport and deliver the gas to customer tanks along a series of pipelines and through a series of valves. In Liquefied Petroleum (LP) gas applications, the gas tank transfer system typically includes one or more overflow internal valves that close in response to a break in the gas storage and distribution system (e.g., due to damage in downstream piping). However, these relief valves tend to undesirably introduce high flow restrictions into the system, which in turn leads to flow disruption and cavitation. Meanwhile, in Liquefied Natural Gas (LNG) applications, the gas distribution system typically includes one or more gate or ball valves that function as the main shutoff valves. However, these gate or ball valves do not have the relief valve function provided by the relief valve and do not provide more, if any, additional functionality.

Disclosure of Invention

According to a first exemplary aspect, a shutoff valve for a fluid transfer or storage system comprises: a valve body defining an inlet port, an outlet port, and a fluid flow passage extending between the inlet and the outlet; a valve seat disposed in the valve body adjacent the outlet port; a shaft at least partially disposed in the valve body; a drive element disposed in the valve body and coupled to the shaft; and a valve member disposed in the valve body and operatively coupled to the shaft. The valve member is movable between a closed position in which the valve member sealingly engages the valve seat to seal the outlet port and an open position in which the valve member is remote from the outlet port and substantially outside of the fluid flow passage such that the valve member provides a minimum flow restriction to fluid flowing through the fluid flow passage.

According to a second exemplary aspect, a shutoff valve for a fluid transfer or storage system comprises: a valve body defining an inlet port, an outlet port, and a fluid flow passage extending between the inlet port and the outlet port; a valve seat disposed in the valve body adjacent the outlet port; a shaft at least partially disposed in the valve body; and a control assembly disposed in the valve body and operatively coupled to the shaft. The control assembly is movable between a closed position in which the control assembly sealingly engages the valve seat to seal the outlet port and an open position in which the control assembly is distal from the outlet port and substantially outside of the fluid flow passage such that the control assembly provides a minimum flow restriction to fluid flowing through the fluid flow passage.

According to a third exemplary aspect, a shutoff valve for a fluid transfer or storage system comprises: a valve body defining an inlet port, an outlet port, and a fluid flow passage extending between the inlet and the outlet; a valve seat disposed in the valve body adjacent the outlet port; a shaft at least partially disposed in the valve body; a drive element disposed in the valve body and coupled to the shaft; and a valve member disposed in the valve body and operatively coupled to the shaft. The valve member is movable between a closed position in which the valve member sealingly engages the valve seat to seal the outlet port and an open position in which the valve member is remote from the outlet port and substantially outside of the fluid flow passage such that the valve member provides a minimum flow restriction to fluid flowing through the fluid flow passage. The shutoff valve further includes a shutoff safety mechanism including a circumferential channel formed in the valve body between the outlet port and the valve seat.

Further in accordance with any one or more of the foregoing first, second, or third exemplary aspects, the shutoff valve may comprise any one or more of the following further preferred forms.

In a preferred form, the valve member is automatically moved to the closed position by the fluid flow rate of the fluid flow passage being greater than a predetermined limit.

In another preferred form, the valve member includes a discharge port configured to: facilitating venting through the fluid flow passage when the fluid flow rate through the fluid flow passage is greater than the predetermined limit.

In another preferred form, the drive element is disposed between an outer wall of the valve body and the valve member.

In another preferred form, a first biasing element is disposed between the drive element and the valve body. The first biasing element is configured to bias the drive element toward a closed position.

In another preferred form, the second biasing element is arranged to bias the drive element and the valve member towards each other.

In another preferred form, the shaft projects outside the valve body and is adapted to be coupled to an external actuator for controlling the shaft.

In another preferred form, the shaft is movable about an axis substantially perpendicular to the fluid flow passage.

In another preferred form, the shaft is rotatable about the axis and the valve member comprises a pendulum type valve member.

In another preferred form, the shaft is slidable along the axis.

In another preferred form, the shut-off valve includes a regulator for regulating the overflow capacity. The adjuster is configured to engage the drive member to change the position of the drive member in the closed position.

In another preferred form, the shaft is rotatable about an axis substantially perpendicular to the fluid flow passage.

In another preferred form, the shaft is slidable along an axis substantially perpendicular to the fluid flow passage.

In another preferred form, the shut-off valve further includes a ramp disposed in the valve body, the ramp defining a guide path oriented at an angle relative to the axis. The shaft is coupled to the control assembly via a coupling element guided by the ramp.

Drawings

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:

FIG. 1 is a perspective view of one example of a relief valve constructed in accordance with the principles of the present invention;

FIG. 2 is a bottom perspective view of the relief valve of FIG. 1;

FIG. 3 is a front perspective view of the internal components of the relief valve of FIG. 1;

FIG. 4 is a plan view of the internal components of the relief valve of FIG. 1, with the relief valve shown with welded end connections;

FIG. 5 is a partial close-up view of the control assembly shown in FIG. 4;

FIG. 6 is another partial close-up view of the control assembly shown in FIG. 4;

FIG. 7 is a plan view of the internal components of the excess flow valve of FIG. 1 when the excess flow valve is in a closed position;

FIG. 8 is similar to FIG. 7 but shows the internal components of the relief valve when the relief valve is in a first bleed position;

FIG. 9 is similar to FIG. 7 but shows the internal components of the relief valve when the relief valve is in an open position;

FIG. 10 is similar to FIG. 7 but shows the internal components of the excess flow valve when the valve actuator of the excess flow valve is being opened or closed;

FIG. 11 illustrates an example of a regulator that may be used with the excess flow valve of FIG. 1 to vary the excess flow capacity of the excess flow valve;

FIGS. 12A and 12B illustrate another example of a relief valve constructed in accordance with the principles of the present invention;

FIG. 13 is a perspective view of another example of a relief valve constructed in accordance with the principles of the present invention;

FIG. 14 is a front perspective view of the internal components of the relief valve of FIG. 13 when the relief valve is in an open position;

FIG. 15 is a partial close-up view of the internal components of the relief valve of FIG. 13 when the relief valve is in a closed position;

FIG. 16 is a perspective view of one example of an actuator assembly that may be used in conjunction with another example of a relief valve constructed in accordance with the teachings of the present invention;

FIG. 17 is a front perspective view of the internal components of the excess flow valve of FIG. 16 when the excess flow valve is in a closed position;

FIG. 18 is a front perspective view of the internal components of the excess flow valve of FIG. 16 when the excess flow valve is in an open position;

FIG. 19 is a front perspective view showing the internal components of the excess flow valve of FIG. 16 in various ones of the closed and open positions;

FIG. 20 illustrates another example of a relief valve constructed in accordance with the principles of the present invention;

FIG. 21 illustrates another example of a relief valve constructed in accordance with the principles of the present invention;

FIG. 22 illustrates another example of a relief valve constructed in accordance with the principles of the present invention; and

FIG. 23 illustrates another example of a relief valve constructed in accordance with the principles of the present invention.

Detailed Description

1-6 depict a low restriction relief valve 100 constructed in accordance with the principles of the present invention. Relief valve 100 is typically configured for gas or liquid applications (e.g., liquefied petroleum applications, liquefied natural gas applications, liquid nitrogen applications), but it will be understood that valve 100 may alternatively or additionally be used for other process control applications. In use, relief valve 100 provides relief closed volume protection while providing minimal flow restriction, thereby minimizing, if not eliminating, flow disruption and cavitation that often occur in known relief valves.

As shown in fig. 1-3, the excess flow valve 100 includes a valve body 104, a bonnet 108 coupled (e.g., removably coupled) to the valve body 104, and a shaft 112 operatively coupled to the valve body 104 via the bonnet 108.

The valve body 104 has an inlet connection 116 defining an inlet port 118, an outlet connection 120 defining an outlet port 122, and a fluid flow passage 124 extending between the inlet port 118 and the outlet port 122. Although not shown herein, when flow valve 100 is used in a gas application, inlet connection 116 is connected to a tank (not shown), such as a cryogenic storage tank, and outlet connection 120 is connected to a conduit downstream of spill valve 100. Of course, when the valve 100 is used in other process transmission or control applications, the inlet connection 116 and/or the outlet connection 120 may be connected to components in those process transmission or control systems as appropriate. The inlet connection 116 and/or the outlet connection 120 may be a threaded connection, a flanged connection, or a welded connection. When relief valve 100 is connected, relief valve 100 facilitates the transfer of fluid (e.g., gas, liquid) from a tank disposed upstream of valve 100 to a conduit disposed downstream of valve 100 via fluid flow passage 124.

In at least this example, the bonnet 108 is removably coupled to the valve body 104 such that the bonnet 108 may be removed and the internal components of the valve 100 disposed within the valve 100 may be repaired or serviced (and, in some cases, replaced) while the flow valve 100 remains embedded. The bonnet 108 provides support for a shaft 112, the shaft 112 being partially disposed within the valve body 104 along an axis substantially perpendicular to the fluid flow passage 124 and protruding outside of the valve body 104 and bonnet 108. So configured, the protruding end 128 of the shaft 112 may be coupled to an external actuator (not shown), such as a pneumatic actuator, a manual actuator, a mechanical actuator, or an electric actuator. When the shaft 112 is actuated, the shaft 112 rotates within the valve body 104 to control fluid flow through the fluid flow passage 124, as will be described below.

With continued reference to fig. 1-3, relief valve 100 also includes a trip safety mechanism 132. In this example, the disconnect safety mechanism 132 takes the form of an area of the valve body 104 that is locally weaker in tension than the rest of the valve body 104. Specifically, the disconnect mechanism 132 employs a passage 136 that extends circumferentially around the valve body 104 between the bonnet 108 and the outlet connection 120. The passage 136 concentrates the tensile stress so that in the event of an accident that damages downstream piping, the valve body 104 fails in the area of the passage 136 before failing at any other location, thereby protecting the integrity of the internal components of the valve body 104 and any fluid is sealed within the valve body 104. Optionally, external reinforcing gussets may be added to the valve body 104 to increase the strength and robustness upstream of the break-off point (location of the break-off mechanism 132).

As shown in fig. 3-6, relief valve 100 also includes a valve seat 150 and a control assembly 154, the control assembly 154 operatively coupled to shaft 112 so as to be movable relative to valve seat 150 to control fluid flow through fluid flow passage 124. As best shown in fig. 3, a valve seat 150 is disposed in the valve body 104 adjacent the outlet port 122. The valve seat 150 may be integrally formed with the valve body 104 or may be removably coupled to the valve body 104 (and thus may be removed or replaced as needed). The valve seat 150 may be made of metal, plastic (e.g., an elastomeric material), or a combination thereof. The control assembly 154 illustrated in fig. 3-6 includes a drive element 158, a valve member 162, a first biasing element 166 disposed between the drive element 158 and the valve body 104, and a second biasing element 170 disposed between the drive element 158 and the valve member 162.

As best shown in fig. 4-6, in this example, drive element 158 has a base portion 174, an arm portion 178, and a cap portion 182. The arm 178 extends outwardly from the base 174 and is secured to and surrounds a portion of the shaft 112 such that the drive element 158 is operatively coupled to the shaft 112. Meanwhile, cap 182 is coupled to a central portion of base 174 and extends outwardly from the central portion of base 174. Cap 182 may be secured to base portion 174 (e.g., via fasteners) or may be integrally formed with base portion 174 of drive element 158. Regardless, when the drive element 158 is in the fully open position, the cap 182 is configured to engage the inner wall 184 of the valve body 104, thereby acting as a stop for the drive element 158 and preventing any further movement of the drive element 158.

Referring still to fig. 4-6, in this example, the valve member 162 takes the form of a flapper 186 having a base 190 and a pair of parallel arms 194. In this example, the base 190 has a substantially rectangular shape, but circular or other shapes are also possible. A seat channel 198 is defined or formed in the base 190 for receiving and sealingly engaging the valve seat 150 to shut off flow through the valve 100 (i.e., to close the valve 100). The seating surface 198 may be metal, plastic (e.g., made of a resilient material), or a combination thereof. The valve member 162 also includes a drain hole 200, the drain hole 200 being defined or formed in a portion of the base 190. The bleed holes 200 are configured to facilitate limited bleed to facilitate pressure equalization across the valve 100, as will be described below. In this example, the drain hole 200 is centrally located on the base 190 and surrounded by the seating surface 198, but in other examples, the drain hole 200 may be disposed elsewhere. The arm 194 extends outwardly from the base 190 and is secured to and encircles a different portion of the shaft 112 such that the valve member 162 is operatively coupled to the shaft 112. As best shown in fig. 6, in one example, the arms 178 of the drive element 158 are fixed to the shaft 112 at a location between (i.e., radially inward of) the arms 194 of the valve member 162.

As best shown in fig. 4, in this example, the first biasing element 166 (although not readily visible) takes the form of a torsion spring having one end attached to an interior portion of the valve body 104 and another end attached to a portion of the drive element 158. Accordingly, the first biasing element 166 is configured to bias the valve member 162 away from the inner wall 184 of the valve body 104 and toward the valve seat 150 (i.e., toward the closed position).

Referring again to fig. 4-6, in this example, the second biasing element 170 takes the form of a torsion spring having one end 204 coupled to a portion of the drive element 158 and another end 208 opposite the end 204 that is fixed about the arm 194 of the valve member 162. So arranged, second biasing element 170 is configured to bias drive element 158 and valve member 162 toward one another.

With the valve 100 configured as described, the valve 100 is configured to provide an overflow containment function while providing minimal flow restriction. Further, relief valve 100 is configured to: in the event of an accident that damages the downstream piping of the valve 100, the integrity of the valve's seat area is protected and any fluid is contained within the valve 100. Fig. 7-10 will be used to describe how relief valve 100 may perform these functions in operation.

Fig. 7 shows the valve 100 in its initial closed position, which occurs when the shaft 112 is not actuated by an external actuator (i.e., no external actuation is applied to the shaft 112). Without this actuation, control assembly 154 is oriented in a closed position in which drive element 158 and valve member 162 are substantially perpendicular to fluid flow passage 124, valve member 162 sealingly engages valve seat 150, and drive element 158 is in direct contact with valve member 162. The drive element 158 not only supports the valve member 162, but also covers the bleed hole 200 of the valve member 162, thereby preventing any fluid flow between the inlet port 118 and the outlet port 122. Control assembly 154 is oriented such that first biasing element 166 biases drive element 158 toward valve seat 150, and second biasing element 170 biases drive element 158 and valve member 162 toward one another. The biasing force exerted by the first and

second biasing elements

166, 170 maintains the control assembly 154 in the closed position in the absence of an external actuation force. Furthermore, any fluid flow upstream of the closed control assembly 154 will exert a net force on the underside 157 of the drive element 158 (in the leftward direction in fig. 7), helping to maintain the drive element 158 and valve member 162 in the closed position.

However, when an external actuation force is applied to the shaft 112 by an external actuator that exceeds the force applied by the first biasing element 166, the shaft 112 rotates in such a manner: causing the valve 100 and, in particular, the control assembly 154 to move to the limited discharge position shown in fig. 8. More specifically, the external actuation force causes the shaft 112 to rotate in such a manner: the drive element 158 rotates about the axis in a clockwise direction away from the valve seat 150 and toward the inner wall 184 of the valve body 104, as shown in fig. 8. In at least this example, the external actuation force will rotate drive element 158 in a clockwise direction until cap portion 182 of drive element 158 contacts inner wall 184, which prevents any further movement of drive element 158. At least initially, the drive element 158 will be moved away from the valve member 162 and thus spaced from the valve member 162 until the pressure at the outlet port 122 is substantially equal to the pressure at the inlet port 118. This occurs because the pressure associated with fluid flow upstream of the valve seat 150 initially exceeds the pressure associated with fluid flow downstream of the valve seat 150; the fluid flow will therefore exert a net force (to the left) on valve member 162, thereby maintaining valve member 162 in sealing engagement with valve seat 150. Since the drive element 158 has been moved away from the valve member 162, uncovering the vent hole 200, fluid will begin to flow (vent) through the vent hole 200 formed in the valve member 162 to the outlet port 122. This venting will continue until pressure equalization has been achieved, whereby the pressure at outlet port 122 has been achieved to be substantially equal to the pressure at inlet port 118.

When pressure equalization is achieved, the fluid flow in the valve 100 will no longer exert any significant force on the valve member 162, thereby enabling the valve 100 (and in particular, the control assembly 154) to move toThe fully open position shown in fig. 9. More specifically, the pressure equalization enables valve member 162 to oscillate or rotate in a clockwise direction toward drive element 158 and into contact with drive element 158. The drive element 158 and valve member 162 are then disposed at an angle relative to the fluid flow passage 124. The angle may be, for example, approximately 5 degrees, approximately 10 degrees, approximately 15 degrees, or some other value between approximately 0 degrees and approximately 90 degrees. Thus, the control assembly 154, and in particular the valve member 162, is seated substantially outside of the fluid flow passage 124, with only the end of the control assembly 154 disposed within the fluid flow passage 124. Thus, the control assembly 154, and in particular the valve member 162, provides little restriction to any fluid flowing in the fluid flow passage 124. In fact, this allows the valve 100 to have a flow coefficient C that is greater than that of known overflow internal valves_vGreater coefficient of flow C_v. For example, the valve 100 may have a flow coefficient C of approximately 250-350_vWhile known spill internal valves typically have a flow coefficient C of approximately 100_v. The size and/or shape of the fluid flow channel 124 may be modified (if desired) to increase or decrease the flow coefficient C_v. Regardless, by providing minimal fluid flow restriction, the valve 100 substantially reduces, if not eliminates, the risk of cavitation, which may occur as a result of flow disruption.

When the control assembly 154 is in the fully open position shown in fig. 9, fluid may freely flow in the fluid flow passage 124 from the inlet port 118 to the outlet port 122. However, in the event that fluid flow entering the valve 100 through the inlet port 118 reaches an overflow condition (condition), the valve 100 (and in particular the control assembly 154) moves to the limited bleed position shown in FIG. 8. As is known in the art, an overflow condition occurs when fluid flow reaches or exceeds a predetermined limit, typically caused by a pressure loss in the process transmission or control system (e.g., due to a downstream pipe having broken, etc.). The predetermined limit may, for example, correspond to a certain percentage (e.g., 200%) of the capacity of the valve 100 designed to process. Regardless, when the flooding condition has been reached, the drag force (drag) from the fluid entering the valve 100 through the input port 118 will exceed the biasing force applied by the second biasing element 170, and thus, the drag force will drive the valve member 162 in a counterclockwise direction. The drag force drives the valve member 162 away from the drive element 158 (the drive element 158 remaining in the fully open position) and toward the valve seat 150 and into sealing engagement with the valve seat 150. With the drive element 158 held in the fully open position, the vent hole 200 in the valve member 162 is exposed so that a limited amount of fluid may flow (i.e., vent) through the vent hole.

It will be appreciated that since in the fully open position the control assembly 154 is seated substantially outside of the fluid flow passage 124, the pressure drop across the valve member 162 is significantly lower than that seen in known spill internal valves. In other words, the valve 100 has the ability to provide a higher relief capacity than known relief internal valves.

In the event that a process transmission or control system failure is repaired, thereby mitigating an overflow condition, limited venting through vent hole 200 continues until pressure equalization has been restored. In other words, control assembly 154 remains in the drain position shown in fig. 8, and fluid flows through drain hole 200 until the pressure at outlet port 122 is substantially equal to the pressure at inlet port 118. When pressure equalization has been restored, the second biasing element 170 pulls the valve member 162 back to the position shown in fig. 9, thereby returning the valve 100 (and specifically the control assembly 154) to the fully open position.

In the event that the process transmission or control system cannot be repaired or it is undesirable to repair the process transmission or control system, the valve 100 can be fully shut off easily and safely by releasing the external actuation (i.e., removing the actuation force applied to the shaft 112). Without any external actuation, the drive element 158 also returns to the closed position shown in fig. 7. More specifically, drive element 158 moves toward valve member 162 and into contact with valve member 162, and valve member 162 has sealingly engaged valve seat 150. This movement of the actuating member 158 covers the vent hole 200, thereby eliminating limited venting through the valve 100 and fully closing the valve 100.

Optionally, spill valve 100 may (as shown in FIG. 11) include an adjuster 300 (e.g., a set screw), which adjuster 300 facilitates adjusting the spill capacity of valve 100. The regulator 300 is exposed in this example and may be actuated by an operator of the valve 100. The regulator 300 is movable in a direction substantially parallel to the fluid flow passage 124. When an operator of the valve 100 moves the regulator 300 inwardly, toward the outlet port 122, the regulator 300 drives the drive element 158 in a counterclockwise direction, which in turn changes the angle of the valve member 162 relative to the fluid flow passage 124. Accordingly, a greater portion of the valve member 162 is disposed within the fluid flow passage 124. This serves to reduce the amount of traction required to move the valve member 162 to the closed position in the event of a spill condition, thereby reducing the spill capacity of the valve 100. Conversely, when an operator of the valve 100 moves the regulator 300 outward, toward the inlet port 118, the drive element 158 moves in a clockwise direction (i.e., drops) such that a smaller portion of the valve member 162 is disposed within the fluid flow passage 124. This action thus serves to increase the amount of tractive force required to move the valve member 162 to the closed position in the event of a spill condition, thereby increasing the spill capacity of the valve 100.

In other examples, the regulator 300 may be internally disposed within the valve 100 and actuated in a different manner (e.g., using an external actuator). Further, the regulator 300 may be arranged differently relative to the control assembly 154 such that the regulator 300 may be movable in different directions (e.g., perpendicular to the fluid flow passage 124) and/or ultimately move the valve member 162 in different manners. Further, while the regulator 300 may be employed to facilitate adjustment of the excess flow capacity of the valve 100, the angle of the valve member 162 may be adjusted without the use of the regulator 300 to achieve a similar effect. Likewise, the biasing

elements

166, 170 may be modified in structure and/or biasing force to vary the relief capacity of the valve 100. For example, the biasing element 166 and/or the biasing element 170 may take the form of an extension spring, a compression spring, a constant force spring, a leaf spring, or other biasing element (e.g., a latch).

It will also be appreciated that the valve body 104, bonnet 108, shaft 112, and/or disconnect shaft mechanism 132 may be different than that shown in fig. 1-10 and still perform the intended function. More specifically, the shape, size, and/or style of the valve body 104 may vary. In one example, the shape and/or size of inlet connection 116 and/or outlet connection 120 may be different, such as when it is desired to utilize relief valve 100 in different environments with different sized tanks and/or conduits. In certain examples, the shaft 112 may be arranged differently, e.g., oriented along different axes or at different locations relative to the flow path (e.g., further away from the outlet port 122). For example, as shown in fig. 12A and 12B, the shaft 112 may be supported in different portions of the valve body 104 and oriented along different axes relative to the valve body 104. In another example, the shaft 112 may be oriented such that clockwise rotation of the shaft 112, rather than counterclockwise rotation, moves the control assembly 154 from the open position to the drain and closed positions. The shaft 112 may also be contained entirely within the valve body 104 such that the shaft 112 does not protrude outside the valve body 104 (and the valve 100 is an internal valve). In this case, it may be desirable to introduce a shaft follower (follower) proximate to the outlet port 122. The disconnect safety mechanism 132 may take other forms as well, if desired. For example, the trip safety mechanism 132 may be formed as a tapered portion of the valve body 104, constructed of a different, weaker material, or formed using a mounting stud with a notch or slot to provide a primary failure location. The position of the trip shaft mechanism 132 may also be reset. For example, when the valve 100 is designed as an internal valve and includes a shaft follower adjacent the outlet port 122, the trip shaft mechanism 132 may be located between the valve seat 150 and the shaft follower.

Alternatively or additionally, the configuration and/or actuation of the control assembly 154 may be different than that shown in fig. 1-10 and still perform the intended function. In other examples, the shape and/or size of the drive element 158 and/or the valve member 162 may be different, for example, to change the relief capacity of the valve 100, to change the necessary actuation force and/or biasing force(s), or for some other reason. In another example, the valve member 162 need not include a bleed orifice 200, in which case the valve 100 would no longer have any type of bleed capability in response to a problem in the process transmission or control system. In other examples, the control assembly 154 may also be actuated in a different manner. Although the control assembly 154 described in connection with fig. 1-10 is externally actuated in a rotational manner, the control assembly 154 may alternatively be externally or internally actuated in a linear (e.g., sliding) manner (e.g., as shown in fig. 13-17).

Fig. 13-15 depict another example of a low restriction relief valve 400 constructed in accordance with the principles of the present invention. Similar to relief valve 100, relief valve 400 is generally configured for use in gas or liquid applications (e.g., liquefied petroleum applications, liquefied natural gas applications, liquefied nitrogen applications), but it will be understood that valve 400 may alternatively or additionally be used in other process control applications. In use, relief valve 400 provides relief closed volume protection while providing minimal flow restriction, thereby minimizing, if not eliminating, flow disruption and cavitation that often occur in known relief valves.

As shown in fig. 13 and 14, relief valve 400 includes: a valve body 404, a bonnet 408, wherein the bonnet 408 is coupled (e.g., removably coupled) to the valve body 404, and a sliding valve stem 410 and an internal shaft 412, both operatively coupled to the valve body 404 via the bonnet 408.

As shown in fig. 13 and 14, the valve body 404 includes an inlet connection 416 defining an inlet port 418, an outlet connection 420 defining an outlet port 422, and a fluid flow passage 424 extending between the outlet port 418 and the outlet port 422. Although not shown herein, when the flow valve 400 is used in a gas application, the inlet connection 416 is connected to a tank (not shown) (e.g., a cryogenic tank) and the outlet connection 420 is connected to a conduit downstream of the excess flow valve 400. Of course, when the valve 400 is used in other process transmission or control applications, the inlet connection 416 and/or the outlet connection 420 may be connected to components in those process transmission or control systems as appropriate. The inlet connection 416 and/or the outlet connection 420 may be threaded, flanged, or welded. When relief valve 400 is connected, relief valve 400 facilitates the transfer of fluid (e.g., gas, liquid) from a tank disposed upstream of valve 400 to a conduit disposed downstream of valve 400 via fluid flow passage 424.

The bonnet 408 is removably coupled to the valve body 404 (at least in this example) such that the bonnet 408 may be removed and the internal components of the valve 400 disposed therein may be repaired or serviced (and in some cases replaced) while the flow valve 400 remains embedded. In this example, the valve cover 408 has a base 426 and a cylindrical portion 428 extending upwardly from the base 426. The base 426 is removably coupled to the top of the valve body 404. The cylindrical body 428 houses the inner shaft 412, wherein the inner shaft 412 is disposed along an axis 429 that is substantially perpendicular (e.g., perpendicular) to the fluid flow passageway 424, and provides support for the sliding valve stem 410, wherein the sliding valve stem is also disposed along the axis 429 (i.e., the valve stem 410 and the shaft 412 are coaxial). The sliding valve stem 410 protrudes outside of the valve cap 408 and, more specifically, outside of the cylindrical body 428 of the valve cap. So configured, the protruding end 430 of the valve stem 410 (or some other component coupled to the valve stem) may be coupled to an external actuator (not shown), such as a pneumatic actuator, a manual actuator, a mechanical actuator, or an electrical actuator, so that the sliding valve stem 410 may be controlled. When the sliding valve stem 410 is actuated, the sliding valve stem 410 moves up or down, which in turn causes the inner shaft 412 to move up or down in the same manner.

With continued reference to fig. 13 and 14, spill valve 400 also includes a disconnect safety mechanism 432. Similar to the disconnect safety mechanism 132 described above, in this example, the disconnect safety mechanism 432 takes the form of an area in the valve body 404 that is locally weaker in tension than the rest of the valve body 404. Specifically, the disconnect mechanism 432 takes the form of a passage 436, wherein the passage 436 extends circumferentially around the valve body 404 between the bonnet 408 and the outlet connection 420. The passage 436 concentrates tensile stresses so that in the event of an accident that damages downstream piping, the valve body 404 fails in the area of the passage 436 before failing at any other location, thereby protecting the integrity of the internal components of the valve body 404 and sealing any fluid within the valve body 404. Optionally, external reinforcing gussets may be added to the valve body 404 to increase the strength and robustness upstream of the break-off point (location of the break-off mechanism 432).

As shown in fig. 14 and 15, relief valve 400 also includes a valve seat 450 and a control assembly 454, wherein control assembly 454 is movable relative to valve seat 450 to control the flow of fluid through fluid flow passage 424. While the valve seat 450 is integrally formed within the valve body 404 adjacent to the outlet port 422, alternatively or additionally, the valve seat 450 may be removably coupled to the valve body 404 (and thus, the valve seat 450 may be removed and replaced when desired). The valve seat 450 may be made of metal, plastic (e.g., an elastomeric material), or a combination thereof. The valve seat 450 may be disposed at an angle relative to the fluid flow passage 424 and the axis 429 (as shown in fig. 14), or may be disposed along an axis that is substantially parallel (e.g., parallel) to the axis 429 (and, therefore, substantially perpendicular to the fluid flow passage 424).

The control assembly 454 is generally movable relative to the valve seat 450 between an open position, in which the valve 400 is open and fluid flow through the fluid flow passageway 424 is permitted, and a closed position, in which the valve 400 is closed and fluid flow through the fluid flow passageway 424 is not permitted. In this example, the control component 454 includes: a sliding valve stem 410; an inner shaft 412; a drive element 458; a valve member 462; a first biasing element 466, wherein the first biasing element 466 is disposed in the cylindrical body 428 of the valve cap 408 and operatively coupled to the sliding valve stem 410; and a second biasing element, wherein the second biasing element is not shown but is disposed between drive element 458 and valve member 462 (and operates in the same manner as second biasing element 170 described above). The inner shaft 412 is coupled (e.g., fixed) to the sliding valve stem 410. The drive element 458 is in turn operatively coupled to the inner shaft 412 via a first coupling member 470 and a second coupling member 472. When the sliding valve stem 410 is externally actuated, moving the sliding valve stem 410, the inner shaft 412 responds by moving in the same manner. This drives the first and

second couplers

470, 472, which facilitate the desired movement of the drive element 458 and the valve member 462, as will be described in greater detail below.

As best shown in fig. 14 and 15, in this example, drive element 458 has a base 474, an arm 478, and a neck 482. The arm 478 extends outwardly from the base 474 and is secured to and surrounds the lever 484, with the lever 484 pivotally disposed in a channel 485 formed in the valve body 404 such that the drive element 458 is pivotally coupled to the valve body 404 and within the valve body 404. The stem 484 and passage 485 are generally arranged to minimize rotational and gross movement relative to the valve body 404, thereby optimizing the sealing engagement between the valve member 462 and the valve seat 450. A neck 482 extends outwardly from a central portion of the base 474. While the neck is integrally formed with the base 474, the neck 482 may alternatively be coupled to the base 474 (e.g., via fasteners).

Still referring to fig. 14 and 15, in this example, the valve member 462 takes the form of a flap 486, wherein the flap 486 has a base portion 490 and a pair of parallel arms 494 (only one of which is visible in fig. 14). In this example, the base 490 has a substantially annular shape, although rectangular or other shapes may alternatively be used. Although difficult to see in fig. 14 and 15, a seat channel 498 is defined or formed along the periphery of the base 490 for receiving and sealingly engaging the valve seat 450 in order to shut off flow through the valve 400 (i.e., in order to close the valve 400). The seating surface 498 may be metal, plastic (e.g., made of an elastomeric material), or a combination thereof. The valve member 462 also includes a bleed hole 500 defined or formed in a portion of the base 490. The bleed holes 500 are configured to facilitate limited venting to facilitate pressure equalization across the valve 400, as will be described below. In this example, the drain hole 500 is centrally located on the base 490 and surrounded by the seat surface 498, although in other examples, the drain hole 500 may be disposed elsewhere. The arms 494 extend outwardly from the base 490 and are secured to and surround different portions of the lever 484 so that the valve member 462 is pivotally coupled to the valve body 404 and within the valve body 404 as with the drive element 458. Although not explicitly shown in fig. 14 and 15, the arms 478 of the drive element 458 are fixed to the lever 484 at a location between (i.e., radially inward of) the arms 494 of the valve member 462.

As best shown in fig. 14, in this example, the first biasing element 466 takes the form of a coil spring 512, wherein the coil spring 512 is disposed within a cylindrical body portion 428 of the valve cover 408. More specifically, the coil spring 512 is disposed between the top 513 of the bonnet 408 and the seat 516, wherein the seat 516 is disposed adjacent an end 518 of the valve stem 410 opposite the protruding end 430. So arranged, the first biasing element 466 is configured to bias the drive element 458 away from the base 426 of the valve cover 408 and toward the valve seat 450 (i.e., toward the closed position (see fig. 15)).

Although not explicitly shown herein, the second biasing element of the valve 400 is identical in structure and function to the second biasing element 170 described above. Thus, the second biasing element of the valve 400 takes the form of a torsion spring having a first end coupled to a portion of the drive element 458 and a second end opposite the first end that is fixed about the arm 494 of the valve member 462. So arranged, the second biasing element of valve 400 is configured to bias drive element 458 and valve member 462 toward one another.

Referring particularly to fig. 15, in this example, the first link 470 takes the form of an H-shaped element 520, wherein the H-shaped element 520 has a portion 521 fixed to the inner shaft 412 (e.g., via a fastener) and another portion 522 pivotally coupled to a second link 472 at a pivot connection 523. When the control assembly 454 is in the open position, and for a significant portion of the travel stroke of the sliding valve stem 410, the coupling member 520 is movably disposed along the axis 429. However, when the sliding valve stem 410 is near the end of its travel stroke and the control assembly 454 is near the closed position, the pivot connection 523 is guided along the ramp 524 and is supported by the ramp 524, wherein the ramp 524 is formed within the valve body 404 and extends inwardly from the valve body 404. As shown in fig. 14, ramp 524 defines a guide path that is angled with respect to axis 429. The guide path may be oriented at about 5 degrees, about 10 degrees, about 15 degrees, or some other angle relative to the axes. In any event, since the ramp 524 defines a slightly curved guide path, the pivot connection 523 guided by the ramp 524 is forced to travel along the curved guide path.

The second coupling 472 is generally configured to convert translational movement of the inner shaft 412 into rotational movement of the drive element 458. In this example, the second coupling member 472 takes the form of a substantially cylindrically shaped element 532, wherein the element 532 has one end 536 pivotally coupled to the first coupling member 470 at a pivot connection 523 and another end 544 pivotally coupled to the neck 482 of the drive element 458 at a pivot connection 548. So arranged, linkage member 532 pivots about pivot connections 523, 548 as valve 400 moves between the open and closed positions.

Where the valve 400 is configured as described, the valve 400 is configured to: providing an overflow containment function and at the same time providing minimal flow restriction. Further, relief valve 400 is configured to: in the event of an accident that damages piping downstream of the valve 400, the integrity of the valve seal area is protected and any fluid is contained within the valve 400. Fig. 14 and 15 will also be used to describe how relief valve 400 may perform these functions in operation.

Fig. 15 shows the valve 400 in its initial closed position, which is similar to the closed position of the valve 100 described above (and shown in fig. 7), and which occurs when the sliding valve stem 410 is not actuated by an external actuator (i.e., no external actuation is applied to the sliding valve stem 410). Without such actuation, the control assembly 454 is oriented in a closed position with the drive element 458 and the valve member 462 slightly angled (but substantially perpendicular) relative to the fluid flow passage 424, the valve member 462 sealingly engaging the valve seat 450, and the drive element 458 in direct contact with the valve member 462. The drive element 458 not only supports the valve member 462, but also covers the bleed hole 500 of the valve member 162, thereby preventing any fluid flow between the inlet port 418 and the outlet port 422. The control assembly 454 is oriented such that the first biasing element 466 biases the drive element 458 toward the valve seat 450, while the second biasing element of the valve 400 biases the drive element 458 and the valve member 462 toward one another. In the absence of an external actuation force, the biasing force applied by the first and second biasing elements maintains the control assembly 454 in this closed position. Furthermore, any fluid flow upstream of the closed control assembly 454 will exert a net force on the underside of the drive element 458, thereby helping to maintain the drive element 458 and valve member 462 in the closed position.

As further shown in fig. 15, when the valve 400 is in the closed position, the coupling element 520 is oriented at an angle relative to the fluid flow passage 424 and the axis 429, wherein the angle corresponds to the angle of the guide path defined by the ramp 524. The coupling element 520 converts the vertical actuation force applied by the external actuator (and transmitted via the valve stem 410 and shaft 412) into a horizontal axial force that is transmitted to the coupling element 532. The coupling element 532 (which is substantially parallel to the fluid flow passage 424 and substantially perpendicular to the axis 429) applies this horizontal force to the valve member 462 (i.e., applies a force in a direction substantially parallel to the fluid flow passage 424) to maintain the valve member 462 in sealing engagement with the valve seat 450. Not only does the coupling element 520 help to translate or utilize the vertical actuation force into an axial force that holds the valve member 462 closed, but also because the curved ramp 524 acts on the pivot connection 523 in the manner described above, the control assembly 454, and in particular the valve member 462, may be held in the closed position with less force than would otherwise be required. In other words, due to the curved ramp 524, the valve stem 410 and shaft 412 need not exert as much force as conventionally required to maintain the valve member 462 in sealing engagement with the valve seat 450. This, in turn, may allow the use of smaller external actuators than would otherwise be required.

However, when an external actuator applies an external actuation force to the sliding valve stem 410 that exceeds the biasing force applied by the first biasing element 466, the valve stem 410 moves in a manner that causes the valve 400 to move to a limited discharge position (which is not shown, but is similar to the limited discharge position of the valve 100 described above (and shown in fig. 8)). More specifically, the valve stem 410 is driven upward away from the valve body 404, which causes the shaft 412 to also move upward. The external actuating force will drive the valve stem 410 upward until the valve stem 410 reaches the end of its travel stroke. At least initially, the drive element 458 will move away from, and thus be spaced from, the valve member 462 until the pressure at the outlet port 422 is substantially equal to the pressure at the inlet port 418. This occurs because the pressure associated with fluid flow upstream of the valve seat 450 initially exceeds the pressure associated with fluid flow downstream of the valve seat 450; thus, the fluid flow will exert a net force (to the left) on the valve member 462, thereby maintaining the valve member 462 in sealing engagement with the valve seat 450. Since the actuating element 458 has been moved away from the valve member 462 so as to uncover the bleed hole 500, fluid will begin to flow (or bleed) through the bleed hole 500 formed in the valve member 462 to the outlet port 422. This venting will continue until the pressure equalizes, thereby achieving that the pressure at the outlet port 422 is substantially equal to the inlet port 418.

When pressure equalization is achieved, the fluid flow within the valve 400 will no longer exert any significant force on the valve member 462, thereby enabling the valve 400 (and in particular the control assembly 454) to move to the open position shown in fig. 14. More specifically, the pressure equalization enables valve member 462 to oscillate or rotate in a clockwise direction toward drive element 458 and into contact with drive element 458. Drive element 458 and valve member 462 are then disposed at an angle relative to fluid flow passageway 424. As shown in fig. 14, the control assembly 454 (and in particular the valve member 462) is seated substantially outside of the fluid flow passage 424, with only an end of the control assembly 454 disposed within the fluid flow passage 424. Thus, the control assembly 454 (and in particular the valve member 462) provides little restriction to any fluid flowing in the fluid flow passage 424. In fact, this allows the valve 400 to have a flow coefficient C that is greater than that used for known overflow internal valves_vGreater coefficient of flow C_v. For example, the valve 400 may have a flow coefficient C of approximately 250-350_vWhile known spill internal valves typically have a flow coefficient C of about 100_v. If desired, the size and/or shape of the fluid flow channel 424 may be altered to increase or decrease the flow coefficient C_v. Regardless, by providing minimal fluid flow restriction, the valve 400 substantially reduces, if not eliminates, the risk of cavitation, which may occur as a result of flow disruption.

When the control assembly 454 is in the fully open position shown in fig. 14, fluid may freely flow in the fluid flow passage 424 from the inlet port 418 to the outlet port 422. However, in the event that fluid flow entering the valve 400 through the inlet port 418 reaches an overflow condition, the valve 400 (and in particular the control assembly 454) moves to the limited drain position discussed above. As is known in the art, an overflow condition occurs when fluid flow reaches or exceeds a predetermined limit, typically caused by a pressure loss in the process transmission or control system (e.g., due to a downstream pipe having broken, etc.). The predetermined limit may, for example, correspond to a percentage (e.g., 200%) of the capacity that the valve 100 is designed to handle. Regardless, when the flooding condition has been reached, the drag force from the fluid entering the valve 400 through the inlet port 418 will exceed the biasing force exerted by the second biasing element 470, and thus, the drag force will drive the valve member 462 in the counterclockwise direction. The drag force drives the valve member 462 away from the driving element 158 (which is held in the fully open position) and toward the valve seat 450 and into sealing engagement with the valve seat 450. With the drive element 458 maintained in the fully open position, the vent hole 500 in the valve member 462 is exposed so that a limited amount of fluid may flow (i.e., vent) through the vent hole 500.

It will be appreciated that since in the fully open position, the control assembly 454 is seated substantially outside of the fluid flow passage 424, the pressure drop across the valve member 462 is significantly lower than that seen in known spill internal valves. In other words, the valve 400 has the ability to provide a higher relief capacity than known relief internal valves.

In the event that a process transmission or control system failure is repaired, thereby mitigating an overflow condition, limited venting through vent hole 500 continues until pressure equalization has been restored. In other words, control assembly 454 remains in the drain position and fluid flows through drain hole 500 until the pressure at outlet port 422 is substantially equal to the pressure at inlet port 418. When pressure equalization has been restored, the second biasing element pulls the valve member 462 back to the position shown in fig. 14, thereby returning the valve 400 (and specifically the control assembly 454) to the fully open position.

In the event that the process transmission or control system cannot be repaired or it is undesirable to repair the process transmission or control system, the valve 400 can be fully shut off easily and safely by releasing the external actuation (i.e., removing the actuation force applied to the valve stem 410). Without any external actuation, the control assembly 454 returns to the closed position shown in fig. 15. More specifically, drive element 458 moves toward valve member 462 and into contact with valve member 462, wherein valve member 462 has sealingly engaged valve seat 450. This movement of the actuating member 458 covers the vent 500, thereby eliminating limited venting through the valve 400 and fully closing the valve 400.

Fig. 16-19 illustrate another example actuator assembly 600 operatively coupled to a low restriction spill valve 604 constructed in accordance with the principles of the present invention. Relief valve 604 is substantially similar to relief valve 400 shown in fig. 13-15, wherein common reference numerals are used to refer to common components.

As shown in fig. 16, the actuator assembly 600 includes a mounting assembly 608 for mounting an actuator 612 to the valve 604 in a manner that does not increase the vertical footprint of the valve 604. The mounting assembly 608 includes a mounting sleeve 616 and a mounting bracket 620. The mounting sleeve 616 is removably coupled to the valve stem 410 (and, thus, is also movable relative to the valve body 404). More specifically, the mounting sleeve 616 is disposed over a substantial portion of the cylindrical portion 428 of the bonnet 408, wherein an upper end 621 of the mounting sleeve 616 is secured to the protruding end 430 of the valve stem 410 via a fastener 617; if desired, the mounting sleeve 616 may be decoupled from the valve stem 410 by removing the fastener 617. Regardless, when the mounting sleeve 616 is coupled to the valve stem 410 in the manner described, the valve stem 410 and the mounting sleeve 616 move upward or downward together such that movement of the sleeve 616 raises or lowers the valve stem 410. Meanwhile, the mounting bracket 620 is removably secured to the base 426 of the bonnet 408 (e.g., via fasteners). When the mounting bracket 620 is secured to the bonnet 408, the mounting bracket 620 is fixed relative to the valve body 404 such that the mounting sleeve 616 is movable relative to the mounting bracket 620.

As also shown in fig. 16, the mounting assembly 608 further includes a pair of

arm portions

618A, 618B, wherein the

arm portions

618A, 618B extend outwardly in a direction perpendicular to the length of the sleeve 616. The first arm portion 618A is coupled to the mounting bracket 620 and extends outwardly from the mounting bracket 620, while the second arm portion 618B is coupled to and extends outwardly from a portion of the mounting sleeve 616 proximate the upper end 621. It will thus be appreciated that, at least in this example, the second arm portion 618B is movable relative to the mounting bracket 620 (and the valve body 404), while the first arm portion 618A is not movable relative to the mounting bracket 620 (and the valve body 404).

The actuator 612 is an adjustable shock absorber having a cylindrical body 622 and a pair of tubular ends 624. Although not shown in fig. 16, the cylinder body 622 has an inlet adapted to receive a source of pressure such that the cylinder body 622 can be pressurized to open the valve 600. The cylindrical body 622 includes a first body portion 623A and a second body portion 623B, wherein the second body portion 623B is telescopically engaged in the first body portion 623A. The first body portion 623A is coupled to (e.g., integrally formed with) one of the tubular end portions 624, and the second body portion 623B is coupled to (e.g., integrally formed with) the other of the tubular end portions 624. As shown in fig. 16, each of the tubular ends 624 defines an opening sized to: when the actuator 612 is mounted to the valve 604 via the mounting assembly 608, a respective one of the

arms

618A, 618B is received. The openings of the tubular end portions 624 of the first body portion 623A receive the arm portions 618A, and the openings of the tubular end portions 624 of the second body portion 623B receive the arm portions 618B. With this arrangement, in response to pressurization of the cylinder body 622 via the inlet, the second body portion 623B can move relative to the first body portion 623A to increase or decrease the interior area of the cylinder body 622.

While the relief valve 604 is described above as being substantially similar to the relief valve 400, the flow valve 604 differs from the flow valve 400 in two primary respects. First, valve 604 comprises a different unit than valve 400 that facilitates limited drainage. Unlike valve 400 (which includes selectively openable vent 500), valve 604 includes a vent mechanism 650, where vent mechanism 650 includes a vent hole 654 and a check valve or vent valve 658, as shown in fig. 17 and 18. The bleed hole 654 is defined or formed in an interior portion of the base portion 490 of the valve member 462 of the valve, while the bleed valve 658 is disposed in an interior portion of the base portion 474 of the drive element 458 at a location adjacent to (e.g., aligned with) the bleed hole 654. The bleed mechanism 650 facilitates back pressure relief by bleeding fluid through the bleed valve 658 when higher pressure fluid is trapped downstream of the sealed valve seat 450. For example, the venting mechanism 650 may facilitate venting when fluid trapped downstream of the valve seat 450 becomes a higher pressure vapor. The bleed mechanism is advantageous because it reduces, if not eliminates, the need for an additional bleed valve installed downstream of the flow valve 604 (e.g., when the trapped downstream fluid becomes a higher pressure vapor). Second, the flow valve 604 includes one or more meter ports 662, wherein the meter ports 662 allow an end user to monitor the pressure drop across the valve 604, for example, to determine plugging. The flow valve 604 shown in fig. 17 and 18 includes a pair of meter ports 662, one of which is disposed adjacent the inlet 418 and one of which is disposed adjacent the outlet 422. However, in other examples, the flow valve 604 may include only one such meter port. Regardless, the gauge port 662 may be plugged when the gauge port 662 is not being used to monitor pressure.

Despite these differences, valve 604 may operate in a manner similar to valve 400. Fig. 16 and 17 show valve 604 in a closed position, which is substantially similar to the closed position of valve 400. Here, however, when it is desired to move the valve 604 from this closed position to the open position shown in fig. 18 (which is substantially similar to the open position of the valve 400), the actuator 612 may be pressurized (e.g., via an inlet of the body 622). Pressurization of the actuator 612 causes the second body portion 623B to move upward relative to the first body portion 623A (at least in fig. 16), thereby expanding the actuator body 622, which lifts the mounting sleeve 616 (which is coupled to the second body portion 623B), and in turn lifts the valve stem 410 (which is coupled to the sleeve 616). Actuation of the valve stem 410 in this manner moves the drive element 458 and the valve member 462 from the closed position shown in fig. 17 to the open position shown in fig. 18. Conversely, the valve 604 may be moved from the open position back to the closed position by depressurizing the actuator 612. Decompression of the actuator 612 causes the second body portion 623B to move downward (at least in this example) relative to the first body portion 623A, thereby retracting the actuator body 622 back to the position shown in fig. 16, which lowers the mounting sleeve 616 (which is coupled to the second body portion 623B), and in turn lowers the valve stem 410. Actuation of the valve stem 410 in this manner moves the drive element 458 and the valve member 462 from the open position shown in fig. 18 back to the closed position shown in fig. 17. Fig. 19 shows the components of the control assembly 454 when the valve 400 is in both the closed and open positions.

It will also be appreciated that valve 400 and/or valve 604 may be different and still perform the intended function. The valve body 404, bonnet 408, valve stem 410, shaft 412, and/or disconnect shaft mechanism 432 may be different than shown and still perform the intended function. More specifically, the shape, size, and/or style of the valve body 404 may vary. In one example, the shape and/or size of inlet connection 416 and/or outlet connection 420 may be different, such as when it is desired to use relief valve 400 in different environments with different sized tanks and/or conduits. In some examples, the shaft 412 may be arranged in a different manner, e.g., oriented along a different axis or located at a different position relative to the flow path (e.g., further away from the outlet port 422). Alternatively or additionally, the configuration and/or actuation of control assembly 454 may be different than shown and still perform the intended function. In other examples, the shape and/or size of the drive element 458 and/or the valve member 462 may be different, for example, to change the relief capacity of the valve, to change the necessary actuation and/or biasing force, or for some other reason. In other examples, the drive element 458 and the valve member 462 may be operatively coupled to the valve stem 410 and the shaft 412 in different manners. For example, as shown in fig. 20, a 2-bar mechanism 670 having a sliding connection 674 may be employed instead of the linking element 472. Of course, the shape of the slot guiding the sliding connection may be different (e.g. the angle may be adjusted) to change the stroke to force correspondence and the stroke to opening correspondence.

Although not described in detail, each of FIGS. 21, 22, and 23 illustrate an

alternative relief valve

700, 800, and 900, respectively, constructed in accordance with one or more aspects of the present invention.

Relief valves

700, 800, and 900 operate in a manner similar to

relief valves

100, 400, and 604 described above.

Finally, it will be appreciated that any of the relief valves described herein may include various combinations of the components described herein and/or a plurality of other components not explicitly shown herein. For example, the valve body of any of the described relief valves may include a gauge port that allows an end user to perform a leak test. As another example, any of the described relief valves may include a flow filter installed at the inlet port and/or the outlet port to reduce the amount of solid contaminants in the process transmission or control system. Furthermore, one or more different components may be introduced around the drive element 158 and valve member 162 such that the opening action is accomplished with a "pressure balancing" component. In one example, the pressure balancing member may take the form of a piston that is slidably disposed against the valve member 162 and initially exposed to only inlet pressure, but that allows flow once the piston slides past the valve member 162 (see fig. 16). In another example, the pressure balancing member may take the form of a butterfly-type element, wherein the butterfly-type element allows flow once pivoted. In another example, the pressure balancing member may take the form of a flat element that slides over the valve member 162. In any event, by using one or more different pressure equalization members, this eliminates the need for initial pressure equalization because the opening valve member is in static equilibrium almost immediately after the opening of the pressure equalization member.

Based on the foregoing, it should be appreciated that the valve described herein provides a safe and effective spill containment function, but does so with minimal flow restriction, thereby minimizing, if not eliminating, flow disruption and cavitation that are problems caused by known spill valves, particularly when installed in a pump supply line. The valve described herein also has a disconnect safety feature that facilitates shut-off in the event of an accident that damages downstream piping, which serves to protect the integrity of the valve sealing area and contain fluid sealingly within the valve and upstream of the valve.

Claims

1. A shutoff valve for a fluid transfer or storage system, comprising:

a valve body defining an inlet port, an outlet port, and a fluid flow passage extending between the inlet port and the outlet port;

a valve seat disposed in the valve body adjacent the outlet port;

a shaft at least partially disposed in the valve body; and

a control assembly disposed in the valve body and operatively coupled to the shaft, the control assembly including a drive element and a valve member, the valve member including a discharge port, and the control assembly being movable between a closed position in which the valve member sealingly engages the valve seat to seal the outlet port, an open position in which the valve member is remote from the outlet port and substantially outside of the fluid flow passage such that the valve member provides a minimum flow restriction to fluid flowing through the fluid flow passage, and a limited discharge position in which the valve member sealingly engages the valve seat to seal the outlet port with the drive element being spaced from the valve member and substantially outside of the fluid flow passage, thereby exposing the discharge port and allowing limited discharge through the discharge port.

2. The shut-off valve of claim 1 wherein the control assembly automatically moves to the closed position in response to fluid flow through the fluid flow passage being greater than a predetermined limit.

3. The shut-off valve of claim 2, wherein the exhaust port is configured to: facilitating venting through the fluid flow passage when the fluid flow rate through the fluid flow passage is greater than the predetermined limit.

4. A shut-off valve according to claim 1, wherein the drive element is provided between an inner wall of the valve body and the valve member.

5. The shut-off valve of claim 1, further comprising a first biasing element disposed between the drive element and the valve body, the first biasing element configured to bias the drive element toward a closed position.

6. A shut-off valve according to claim 5, further comprising a second biasing element arranged to bias the drive element and the valve member towards each other.

7. Shut-off valve according to claim 1, wherein the shaft protrudes outside the valve body and is adapted to be coupled to an external actuator for controlling the shaft.

8. A shut-off valve according to claim 7, wherein the shaft is movable about an axis substantially perpendicular to the fluid flow passage.

9. A shut-off valve as claimed in claim 8, wherein the shaft is rotatable about the axis and wherein the valve member comprises an oscillating valve member.

10. A shut-off valve according to claim 8 wherein the shaft is slidable along the axis.

11. The shut-off valve of claim 1, further comprising a regulator for regulating an excess flow capacity of the shut-off valve, the regulator configured to engage the drive element to change the position of the drive element in the closed position.

12. A shutoff valve for a fluid transfer or storage system, comprising:

a valve seat disposed in the valve body adjacent the outlet port;

a shaft at least partially disposed in the valve body; and

a control assembly disposed in the valve body and operatively coupled to the shaft, the control assembly including a drive element and a valve member, the valve member including a discharge port, and the control assembly being movable between a closed position in which the control assembly sealingly engages the valve seat to seal the outlet port, an open position in which the control assembly is remote from the outlet port and substantially outside of the fluid flow passage such that the control assembly provides a minimum flow restriction to fluid flowing through the fluid flow passage, and a limited discharge position in which the valve member sealingly engages the valve seat to seal the outlet port with the drive element being spaced from the valve member and substantially outside of the fluid flow passage, thereby exposing the discharge port and allowing limited discharge through the discharge port.

13. A shut-off valve as claimed in claim 12, wherein the drive element is configured to move the valve member between a closed position in which the valve member sealingly engages the valve seat to seal the outlet port and an open position in which the valve member is remote from the outlet port in response to actuation of the shaft.

14. The shut-off valve of claim 12, wherein the valve member automatically moves to the closed position in response to fluid flow through the fluid flow passage being greater than an excess flow capacity of the shut-off valve.

15. The shut-off valve of claim 12, further comprising a first biasing element disposed between the drive element and the valve body, the first biasing element configured to bias the drive element toward a closed position.

16. A shut-off valve as claimed in claim 15, further comprising a second biasing element arranged to bias the drive element and the valve member towards each other.

17. A shut-off valve according to claim 12, wherein the shaft is rotatable about an axis substantially perpendicular to the fluid flow passage.

18. A shut-off valve according to claim 12, wherein the shaft is slidable along an axis substantially perpendicular to the fluid flow passage.

19. The shutoff valve of claim 18, further comprising a ramp disposed in the valve body, the ramp defining a guide path oriented at an angle relative to the axis, wherein the shaft is coupled to the control assembly via a coupling element guided by the ramp.

20. A shutoff valve for a fluid transfer or storage system, comprising:

a valve seat disposed in the valve body adjacent the outlet port;

a shaft at least partially disposed in the valve body;

a control assembly disposed in the valve body and operatively coupled to the shaft, the control assembly including a drive element and a valve member, the valve member including a discharge port, and the control assembly being movable between a closed position in which the valve member sealingly engages the valve seat to seal the outlet port, an open position in which the valve member is remote from the outlet port and substantially outside of the fluid flow passage such that the valve member provides a minimum flow restriction to fluid flowing through the fluid flow passage, and a limited discharge position in which the valve member sealingly engages the valve seat to seal the outlet port with the drive element being spaced from the valve member and substantially outside of the fluid flow passage, thereby exposing the discharge port and allowing limited discharge through the discharge port; and

a disconnect safety mechanism including a circumferential channel formed in the valve body between the outlet port and the valve seat.