CROSS-REFERNCE TO RELATED APPLICATION

This Application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 62/573,661 filed on October 17, 2017, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This disclosure relates to stuffing boxes used in oilfield operations, and, in particular, to pollution control valves for stuffing boxes.

BACKGROUND OF THE DISCLOSURE In oilfield operations, stuffing boxes are used to form a seal between the wellhead and piping passing through the wellhead to prevent leakage of wellbore fluids between the wellhead and the piping. For example, progressive cavity pump systems include a drive shaft (sometimes referred to as a "polished rod") that drives rotation of a drive string (sometimes referred to as a "sucker rod"), which, in turn, drives a progressing cavity pump located at the bottom of the wellbore to produce wellbore fluids to the surface through the wellhead. The drive shaft of a progressive cavity pump system passes through a stuffing box that is connected to the wellhead to form a seal between the wellhead and the drive shaft.

A pollution control valve is sometimes provided within the flow tree of a wellhead pump system to prevent a failure of the drive shaft from allowing wellbore fluids to flow up through the stuffing box and thereby spill out into the environment. At least some conventional pollution control valves use a spring-loaded flap that automatically closes when the drive shaft fails. But, the spring-loaded flap is continually forced against the drive shaft during operation of the pump system, which exerts wear on the drive shaft that can cause leakage (e.g., at the stuffing box, etc.) and/or premature failure of the drive shaft. Some conventional pollution control valves attempt to mitigate the wear on the drive shaft using a plastic wear pad on the flap, but the drive shaft still experiences wear that over time can allow pollutive wellbore fluids to leak.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter. Nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In a first aspect, a pollution control valve is provided for a stuffing box of a pump system. The pollution control valve includes a body having an internal bore configured to receive a drive shaft of the pump system. The body includes a sealing pocket that intersects the internal bore. The pollution control valve includes a sealing sphere held within the sealing pocket of the body. The sealing sphere is moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore. The pollution control valve includes an actuator configured to bias the sealing sphere toward the closed position. The sealing sphere is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore.

In some embodiments, the bias of the actuator is configured to move the sealing sphere from the open position to the closed position upon the drive shaft exiting the internal bore.

In some embodiments, the sealing sphere floats within the sealing pocket such that the sealing sphere is configured to move in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore. In some embodiments, the sealing sphere is configured to rotate within the sealing pocket in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

In some embodiments, the actuator includes a spring.

In some embodiments, the actuator includes a piston configured to extend to move the sealing sphere from the open position to the closed position.

In some embodiments, the internal bore extends a length along a central longitudinal bore axis. The sealing pocket extends a length along a central longitudinal pocket axis that is angled at an oblique angle relative to the central longitudinal bore axis of the internal bore.

In some embodiments, a diameter of the sealing pocket is greater than a diameter of the internal bore.

In some embodiments, the actuator includes a piston configured to move to an extended position to move the sealing sphere from the open position to the closed position. The extended position of the piston indicates that the sealing sphere has been moved to the closed position.

In some embodiments, the sealing sphere includes an external layer having a coefficient of friction less than approximately 0.1μ.

In a second aspect, a stuffing box assembly is provided for a pump system. The stuffing box assembly includes a stuffing box configured to be connected to a well head. The stuffing box is configured to receive a drive shaft of the pump system through the stuffing box. The stuffing box assembly includes a pollution control valve that includes a body having an internal bore. The body is connected to the stuffing box such that the drive shaft is configured to extend through the internal bore. The body includes a sealing pocket that intersects the internal bore. The pollution control valve includes a sealing sphere held within the sealing pocket of the body. The sealing sphere is moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore. The pollution control valve includes an actuator configured to bias the sealing sphere toward the closed position. The sealing sphere is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore.

In some embodiments, the bias of the actuator of the pollution control valve is configured to move the sealing sphere from the open position to the closed position upon the drive shaft exiting the internal bore.

In some embodiments, the sealing sphere of the pollution control valve floats within the sealing pocket such that the sealing sphere is configured to move in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

In some embodiments, the sealing sphere of the pollution control valve is configured to rotate within the sealing pocket in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

In some embodiments, the actuator of the pollution control valve includes a spring.

In some embodiments, the actuator of the pollution control valve includes a piston configured to extend to move the sealing sphere from the open position to the closed position.

In some embodiments, the internal bore of the pollution control valve extends a length along a central longitudinal bore axis. The sealing pocket extends a length along a central longitudinal pocket axis that is angled at an oblique angle relative to the central longitudinal bore axis of the internal bore.

In some embodiments, a diameter of the sealing pocket of the pollution control valve is greater than a diameter of the internal bore.

In a third aspect, a pollution control valve is provided for a stuffing box of a pump system. The pollution control valve includes a body having an internal bore configured to receive a drive shaft of the pump system. The body includes a sealing pocket that intersects the internal bore. A sealing member is held within the sealing pocket of the body. The sealing member is moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore. The pollution control valve includes an actuator configured to bias the sealing member toward the closed position. The sealing member is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore. The bias of the actuator is configured to move the sealing member from the open position to the closed position upon the drive shaft exiting the internal bore.

In some embodiments, the sealing member is a sphere.

Other aspects, features, and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of the inventions disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings facilitate an understanding of the various embodiments. FIG. 1 is a schematic view of an exemplary cavity pump system in an earth formation. FIG. 2 is a schematic view of an exemplary drive head of the cavity pump system shown in FIG. 1.

FIG. 3 is a cross-sectional view of a stuffing box assembly of the cavity pump system shown in FIG. 1 according to an exemplary embodiment.

FIG. 4 is a cross-sectional view of a pollution control valve of the stuffing box assembly shown in FIG. 3 according to an exemplary embodiment.

FIG. 5 is another cross-sectional view of the pollution control valve shown in FIG. 4 illustrating the pollution control valve in a closed position according to an exemplary embodiment. FIG. 6 is another cross-sectional view of the stuffing box assembly shown in FIG. 3 illustrating a failure of a drive shaft of the cavity pump system shown in FIG. 1.

FIG. 7 is another cross-sectional view of the stuffing box assembly shown in FIG. 3 illustrating the pollution control valve shown in FIGS. 4 and 5 in a closed position according to the exemplary embodiment.

Corresponding reference characters indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION

Certain embodiments of the disclosure provide a pollution control valve for a stuffing box of a pump system. The pollution control valve includes a body having an internal bore configured to receive a drive shaft of the pump system. The body includes a sealing pocket that intersects the internal bore. The pollution control valve includes a sealing sphere held within the sealing pocket of the body. The sealing sphere is moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore. The pollution control valve includes an actuator configured to bias the sealing sphere toward the closed position. The sealing sphere is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore.

Certain embodiments of the disclosure provide a pollution control valve that reduces the wear experienced by a drive shaft during operation of a pump system. Certain embodiments of the disclosure provide a pollution control valve that reduces leakage of wellbore fluid. Certain embodiments of the disclosure provide a pollution control valve that extends the life of a drive shaft of a pump system. Certain embodiments of the disclosure provide a pollution control valve that automatically closes upon the failure of the drive shaft of a pump system. Certain embodiments of the disclosure provide an automatic pollution control valve that is independent of the flow and pressure of the wellbore fluid of a wellbore.

FIG. 1 illustrates an exemplary cavity pump system 10 in an earth formation (e.g., for use in an oilfield, etc.). The pump system 10 includes a drive head 12, a wellhead frame 14, a stuffing box 16, an electric motor 18, and a drive system 20 (e.g., a belt and sheave drive system, etc.). The drive head 12, the wellhead frame 14, the stuffing box 16, the electric motor 18, and the drive system 20 are mounted on a flow tee 22. In the example, of FIG. 1 , the flow tee 22 includes a blowout preventer 24 which is, in turn, mounted on a wellhead 26 of a wellbore 28. The drive head 12 supports and drives a drive shaft 30, which is sometimes referred to as a "polished rod". More particularly, the drive shaft 30 is supported by a clamp 32 that engages an output shaft 34 of the drive head 12 to drive rotation of the drive shaft 30. The drive shaft 30 drives rotation of a drive string 36, which is sometimes referred to as a "sucker rod". The drive string 36 drives a progressing cavity pump 38 located at the bottom of the wellbore 28 to produce well fluids to the surface through the wellhead 26. The drive shaft 30 extends through the stuffing box 16 such that the stuffing box 16 provides a seal between the drive shaft 30 and the wellhead 26 to prevent wellbore fluid (e.g. , oil, gas, etc.) from leaking out where the drive shaft 30 transitions from the drive head 12 to the flow tee 22 and thereby the wellhead 26.

In the example of FIG. 1 , the wellhead frame 14 of the drive head 12 is open sided to expose the drive shaft 30 and thereby enable a service crew to install a safety clamp (not shown) on the drive shaft 30, perform maintenance on stuffing box 16, and/or the like. FIG. 2 illustrates another example of a drive head 40 for use with the cavity pump system 10 (i.e., corresponding to the portion of the system 10 above the dashed line 42). The drive head 40 includes a stuffing box 44 mounted to the drive head 40, as is shown in FIG. 2. Because the stuffing box 44 is integrated into the drive head 40, the pump system 10 does not include a wellhead frame. FIG. 3 illustrates an exemplary embodiment of a stuffing box assembly 100 that can be used with the cavity pump system 10 shown in FIG. 1. For example, the stuffing box assembly 100 can be used in place of the stuffing box 16 shown in FIG. 1 or the stuffing box 44 shown in FIG. 2. The stuffing box assembly 100 includes a stuffing box 102 and a pollution control valve 104 that is configured to provide pollution protection for the stuffing box 102, as will be described in more detail below. The stuffing box 102 includes a housing 106 that extends a length from an end portion 108 to an opposite end portion 110. The housing 106 includes an internal passage 112 that extends through the length of the housing 106 along a central longitudinal axis 114.

The housing 106 of the stuffing box 102 is configured to be connected between a wellhead (e.g., the wellhead 26 shown in FIG. 1, etc.) and a drive head (e.g., the drive head 12 shown in FIG. 1, the drive head 40 shown in FIG. 2, etc.) of a pump system (e.g., the cavity pump system 10 shown in FIG. 1, etc.) such that a drive shaft 116 of the pump system extends through the internal passage 112 of the housing 106 of the stuffing box 102, as is shown in FIG. 3. More particularly, the end portion 108 of the housing 106 is configured to be mounted, whether directly or indirectly, to the drive head of the pump system such that the internal passage 112 is aligned to receive the drive shaft 116 therein from the drive head. The end portion 110 of the housing 106 is configured to be mounted, whether directly or indirectly, to the wellhead of the pump system. For example, in the exemplary embodiment, the end portion 110 of the housing 106 is mounted directly to the pollution control valve 104 such that the housing 106 is mounted indirectly to the wellhead. The internal passage 112 of the housing 106 is aligned relative to the wellhead such that the drive shaft 116 extends outward from the internal passage 112 through any intervening component(s) (e.g., the pollution control valve 104, the flow tee 22 shown in FIG. 1, the blowout preventer 24 shown in FIG. 1, etc.) and into the wellhead. The housing 106 of the stuffing box 102 holds one or more sealing components 1 18 within the internal passage 1 12 that provide a fluid seal with the drive shaft 1 16 to prevent wellbore fluid from flowing up through the internal passage 1 12 of the stuffing box 102.

As will be described in more detail below, the pollution valve assembly 104 is operatively connected to the stuffing box 102 to provide a valve that automatically closes upon failure of the drive shaft 1 16 to prevent wellbore fluid from flowing up through the stuffing box 102 and spilling out into the environment. The pollution control valve 104 includes a body 120 that extends a length from an end portion 122 to an opposite end portion 124. The body 120 includes an internal bore 126 that extends through the length of the body 120 along a central longitudinal axis 128. The central longitudinal axis 128 may be referred to herein as a "central longitudinal bore axis".

In the exemplary embodiment, the pollution control valve 104 is configured to be operatively connected between the stuffing box 102 and the wellhead of the pump system. More particularly, the end portion 122 of the body 120 is configured to be mounted directly to the end portion 1 10 of stuffing box 102 such that the internal bore 126 is aligned with the internal passage 1 12 of the stuffing box 102 to receive the drive shaft 1 16 through the internal bore 126. The end portion 124 of the body 120 of the pollution control valve 104 is configured to be mounted, whether directly or indirectly, to the wellhead of the pump system. For example, the end portion 124 of the body 120 can be mounted directly to an intervening component (e.g. , the flow tee 22, the blowout preventer 24, etc.) such that the body 120 of the pollution control valve 104 is mounted indirectly to the wellhead. The internal bore 120 of the pollution control valve 104 is aligned relative to the wellhead such that the drive shaft 116 extends outward from the internal bore 126 through any intervening component(s) (e.g. , the flow tee 22, the blowout preventer 24, etc.) and into the wellhead.

In another embodiment, the pollution control valve 104 is configured to be operatively connected between the stuffing box 102 and the drive head (e.g., the drive head 12, the drive head 40, etc.) of the pump system. More particularly, the end portion 124 of the body 120 can be mounted directly to the end portion 108 of the stuffing box 102 with the internal bore 126 aligned to receive the drive shaft 116 from the drive head and such that the drive shaft 116 extends outward from the pollution control valve 104 into the internal passage 1 12 of the stuffing box 102.

In the exemplary embodiment, the body 120 of the pollution control valve 104 is mounted to the housing 106 of the stuffing box 102 using a threaded connection, as can be seen in FIG. 3. But, additionally or alternatively the body 120 can be mounted to the housing 106 using any other suitable connection type, such as, but not limited to, using bolts, screws, a latch, a clip, a clamp, adhesive, bonding, and/or the like. In one example, the pollution control valve 104 is configured to be mounted to an existing stuffing box 102 to retrofit the stuffing box 102 with the pollution control valve 104. In some other embodiments, the body 120 of the pollution control valve 104 is integrally formed as a single unitary structure with the housing 102 of the stuffing box 102.

Referring now to FIGS. 4 and 5, the body 120 of the pollution control valve 104 includes a sealing pocket 130 that extends a length through the body 120 along a central longitudinal axis 132 from an end portion 134 to an opposite end portion 136. As can be seen in FIGS. 4 and 5, the end portion 136 of the sealing pocket 130 intersects the internal bore 126 of the body 120. In some examples, the central longitudinal axis 132 of the sealing pocket 130 extends at an oblique angle a relative to the central longitudinal axis 128 of the internal bore 126 such that the sealing pocket 130 slopes downwardly, as viewed in FIGS. 4 and 5, away from the internal bore 126. The sealing pocket 130 is larger than the internal bore 126 in some examples. More particularly, the diameter D of the sealing pocket 130 is greater than the diameter Di of the internal bore 126, as can also be seen in FIGS. 4 and 5. The central longitudinal axis 132 may be referred to herein as a "central longitudinal pocket axis". The pollution control valve 104 includes a sealing sphere 138 held within the sealing pocket 130. The sealing sphere 138 is moveable within the sealing pocket 130 between an open position shown in FIG. 4 and a closed position shown in FIG. 5. In the open position, the sealing sphere 138 is retracted into the sealing pocket 130 in the direction of the arrow 140 with the drive shaft 116 (not shown in FIG. 5) of the pump system (e. g. , the cavity pump system 10 shown in FIG. 1 , etc.) extending through the internal bore 126, as can be seen in FIG. 4. In the closed position of the sealing sphere 138, the sealing sphere 138 extends into the internal bore 126 such that the sealing sphere 138 forms an obstruction that provides a fluid seal within the internal bore 126, as can be seen in FIG. 5. Accordingly, the closed position of the sealing sphere 138 prevents fluid from flowing through the internal bore 126 to thereby prevent wellbore fluid from flowing up through the internal passage 1 12 (FIG. 3) of the stuffing box 102 (FIG. 3) and spilling out into the environment. As will be described in more detail below, in the exemplary embodiment the sealing sphere 138 is configured to float within the sealing pocket 130 to accommodate motion of the drive shaft 116 during operation of the pump system.

The size, shape, and/or the like of the sealing sphere 138 and the end portion 136 of the sealing pocket 130 can be selected to enable the sealing sphere 138 to nest within the end portion 136 such that the closed position of the sealing sphere 138 provides a fluid-tight seal within the internal bore 126. In the exemplary embodiment, the end portion 136 of the sealing pocket 130 is rounded to provide the sealing sphere 138 and the end portion 136 with complementary shapes that facilitate providing the fluid seal, as shown in the various exemplary illustrations. Despite being referred to herein as a "sphere", the sealing sphere 138 is not limited to having the shape of a sphere. Rather, in other embodiments the sealing sphere 138 includes any other shape that enables the sealing sphere 138 to provide a fluid seal within the internal bore 126 in the closed position, such as, but not limited to, a different curved shape, a block shape, a wedge shape, and/or the like. Accordingly, the sealing sphere 138 may be referred to herein as a "sealing member". It should be understood that in embodiments wherein the sealing sphere 138 includes a non-sphere shape, the end portion 136 of the sealing pocket 130 can have a complementary shape with the sealing sphere 138 to facilitate providing the fluid seal within the internal bore 126. Optionally, the sealing sphere 138 (or other shaped sealing member) includes an external layer (e.g., a coating, a wrap, etc.) that is configured to reduce stiction and/or friction, such as, but not limited to, a material having a coefficient of friction less than approximately 0. 1 μ, polytetrafiuoroethylene (PTFE, e.g. , Teflon®, etc.), perfiuoroalkoxy polymer resin (PFA, e.g., Teflon®, etc.) rubber, and/or the like.

The pollution control valve 104 includes an actuator 142 that is operatively connected to the sealing sphere 138 to bias the sealing sphere 138 toward the closed position shown in FIG. 5. The sealing sphere 138 is held in the open position against the bias of the actuator 142 by the presence of the drive shaft 1 16 within the internal bore 126, as will be described below and should be apparent from FIG. 4. As will also be described below, upon failure of the drive shaft 1 16, the bias of the actuator 142 is configured to move the sealing sphere 138 from the open position shown in FIG. 4 to the closed position shown in FIG. 5.

In the exemplary embodiment, the actuator 142 includes a piston 144 and a spring 146 that is operatively connected to the piston 144. More particularly, in one example, the piston 144 is held by a bonnet 148 and is moveable within a passage 150 of the bonnet 148 between a retracted position shown in FIG. 4 and an extended position shown in FIG. 5. In the retracted position of the piston 144, the sealing sphere 138 is in the open position, as can be seen in FIG. 4. In the extended position, the sealing sphere 138 is in the closed position, as can be seen in FIG. 5. The spring 146 is operatively connected between a flange 152 of the piston 144 and a shoulder 154 of the passage 150 of the bonnet 148 such that the spring 146 is configured to bias the piston 144 toward the extended position. An end portion 156 of the piston 144 engages the sealing sphere 138 such that the bias of the piston 144 toward the extended position provided by the spring 146 biases the sealing sphere 138 toward the closed position.

In addition or alternative to the spring 146, the piston can be biased to the extended position using any other type of actuator, such as, but not limited to, an electric motor, a linear actuator (e.g. , a ball screw, a lead screw, a rotary screw, another screw-type actuator, a hydraulic linear actuator, a pneumatic linear actuator, a solenoid, a servo, another type of linear actuator, etc.), a hydraulic actuator (e.g., a hydraulic pump system, etc.), a pneumatic actuator, a servo, and/or the like. Moreover, in some other embodiments, the piston 144 is not included and the spring 146 is engaged with the sealing sphere 138 such that the spring 146 directly biases the sealing sphere 138 to the closed position shown in FIG. 5.

In one example of an alternative embodiment, the sealing sphere 138 (or other shaped sealing member as described above) is integrally formed as a single unitary structure with the end portion 156 of the piston 144. Although shown as being mounted to the body 120 of the pollution control valve 104 using bolts 158, additionally or alternatively the bonnet 148 can be mounted to the body 120 using any other suitable connection type, such as, but not limited to, a threaded connection, screws, a latch, a clip, a clamp, adhesive, bonding, and/or the like. In some other embodiments, the bonnet 148 is integrally formed as a single unitary structure with the body 120.

Referring again to FIG. 3, during operation of the pump system the drive shaft 1 16 extends through the internal passage 1 12 of the stuffing box 102 and through the internal bore 126 of the pollution control valve 104 to the wellhead. During operation, the drive shaft 116 reciprocates within the internal passage 1 12 and the internal bore 126 along the central longitudinal axes 114 and 128 in the directions of the arrows 160 and 162. The drive shaft 1 16 also rotates about the central longitudinal axes 114 and 128 during operation of the pump system. As shown in FIG. 3, the sealing sphere 138 of the pollution control valve 104 is held in the open position against the bias of the actuator 142 by the presence of the drive shaft 116 within the internal bore 126. The bias of the actuator 142 forces the sealing sphere 138 into engagement with the drive shaft 1 16 during operation of the pump system, as can be seen in FIG. 3. As briefly described above, the sealing sphere 138 is configured to float within the sealing pocket 130 of the pollution control valve 104 to accommodate the reciprocating and/or rotational motion of the drive shaft 1 16 during operation of the pump system. For example, the sealing sphere 138 is configured to move linearly in the direction of the arrow 140 in response to reciprocating and/or rotational motion of drive shaft 116. Moreover, and for example, the sealing sphere 138 is configured to rotate about an axis 164 in the directions of the arrows 166 and 168 in response to the reciprocating motion of the drive shaft 1 16. The sealing sphere 138 is also configured to rotate about an axis 170 in response to the rotational motion of the drive shaft 1 16, for example.

The various rotational and linear movements of the sealing sphere 138, the curved shape of the sealing sphere 138, the optional external layer that is configured to reduce stiction and/or friction described above, and/or the like reduces the wear experienced by the drive shaft 1 16 during operation of the pump system. For example, the pollution control valve 104 exerts less wear on the drive shaft 1 16 as compared to at least some known pollution control valves. By reducing the wear experienced by the drive shaft 1 16, the pollution control valve 104 reduces leakage of wellbore fluid (e.g., at the stuffing box 102, etc.), extends the life of the drive shaft 1 16, and/or the like.

Referring now to FIGS. 6 and 7, the pollution control valve 104 is configured to automatically close upon failure of the drive shaft 1 16. More particularly, when the drive shaft 1 16 fails (e.g., by breaking, being severed, etc.), the drive shaft 1 16 falls down through the internal passage 112 and the internal bore 126 into the wellbore and thereby exits the internal bore 126 of the pollution control valve 104. With the drive shaft 116 no longer present within the internal bore 126, the bias exerted by the spring 146 moves the piston 144 in the direction of the arrow 172 from the retracted position shown in FIG. 6 to the extended position shown in FIG. 7. Movement of the piston 144 in the direction of the arrow 172 to the extended position moves the sealing sphere 138 from the open position shown in FIG. 6 to the closed position shown in FIG. 7 wherein the sealing sphere 138 prevents fluid from flowing up in the direction of the arrow 174 through the internal bore 126. Accordingly, upon failure of the drive shaft 1 16, the bias of the actuator 142 automatically closes the pollution control valve 104 to prevent wellbore fluid from flowing up in the direction of the arrow 174 through the internal passage 1 12 of the stuffing box 102 and thereby spilling out into the environment. The pollution control valve 104 thereby provides the pump system with pollution control. As should be apparent from the above description and the various illustrations, the automatic closing of the pollution control valve 104 is independent of the flow and pressure of the wellbore fluid.

In some examples, the extension of the piston 144 to the extended position shown in FIGS. 5 and 7 indicates that the pollution control valve 104 has been closed. For example, an operator can visually inspect whether the piston 144 has been extended and thereby confirm that that the sealing sphere 138 has moved to the closed position that seals the internal bore 126. Optionally, the piston 144 includes a marking and/or other indication that indicates that the piston 144 is in the extended position. The pollution control valve 104 can be reset to the open position by moving the piston 144 from the extended position to the retracted position, for example by pulling the piston 144 in the direction of the arrow 140, by removing the bias of the actuator 142 (e.g. , deactivating a hydraulic, linear, electric, pneumatic, and/or other actuator, etc.), by reversing the actuator 142 (e.g., reversing a hydraulic linear, electric, pneumatic, and/or other actuator, etc.), and/or the like. The slope of the sealing pocket 130 and/or larger size of the sealing pocket 130 as compared to the internal bore 126 described above may facilitate retraction of the sealing sphere 130 from the closed position to the open position during resetting of the pollution control valve 104.

The following clauses describe further aspects of the disclosure:

Clause Set A:

Al . A pollution control valve for a stuffing box of a pump system, said pollution control valve comprising:

a body having an internal bore configured to receive a drive shaft of the pump system, the body comprising a sealing pocket that intersects the internal bore;

a sealing sphere held within the sealing pocket of the body, the sealing sphere being moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore; and

an actuator configured to bias the sealing sphere toward the closed position, wherein the sealing sphere is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore.

A2. The pollution control valve of clause Al , wherein the bias of the actuator is configured to move the sealing sphere from the open position to the closed position upon the drive shaft exiting the internal bore.

A3. The pollution control valve of clause Al , wherein the sealing sphere floats within the sealing pocket such that the sealing sphere is configured to move in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

A4. The pollution control valve of clause Al , wherein the sealing sphere is configured to rotate within the sealing pocket in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

A5. The pollution control valve of clause Al , wherein the actuator comprises a spring. A6. The pollution control valve of clause Al , wherein the actuator comprises a piston configured to extend to move the sealing sphere from the open position to the closed position.

A7. The pollution control valve of clause Al , wherein the internal bore extends a length along a central longitudinal bore axis, and the sealing pocket extends a length along a central longitudinal pocket axis that is angled at an oblique angle relative to the central longitudinal bore axis of the internal bore.

A8. The pollution control valve of clause Al , wherein a diameter of the sealing pocket is greater than a diameter of the internal bore.

A9. The pollution control valve of clause Al , wherein the actuator comprises a piston configured to move to an extended position to move the sealing sphere from the open position to the closed position, the extended position of the piston indicating that the sealing sphere has been moved to the closed position.

A10. The pollution control valve of clause Al , wherein the sealing sphere comprises an external layer having a coefficient of friction less than approximately 0.1 μ.

Clause Set B:

Bl . A stuffing box assembly for a pump system, said stuffing box assembly comprising:

a stuffing box configured to be connected to a wellhead, the stuffing box being configured to receive a drive shaft of the pump system through the stuffing box; and

a pollution control valve comprising:

a body having an internal bore, the body being connected to the stuffing box such that the drive shaft is configured to extend through the internal bore, the body comprising a sealing pocket that intersects the internal bore; a sealing sphere held within the sealing pocket of the body, the sealing sphere being moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore; and

an actuator configured to bias the sealing sphere toward the closed position, wherein the sealing sphere is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore.

B2. The stuffing box assembly of clause Bl , wherein the bias of the actuator of the pollution control valve is configured to move the sealing sphere from the open position to the closed position upon the drive shaft exiting the internal bore.

B3. The stuffing box assembly of clause B 1 , wherein the sealing sphere of the pollution control valve floats within the sealing pocket such that the sealing sphere is configured to move in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

B4. The stuffing box assembly of clause Bl , wherein the sealing sphere of the pollution control valve is configured to rotate within the sealing pocket in response to at least one of rotational or reciprocal motion of the drive shaft within the internal bore.

B5. The stuffing box assembly of clause Bl , wherein the actuator of the pollution control valve comprises a spring.

B6. The stuffing box assembly of clause Bl , wherein the actuator of the pollution control valve comprises a piston configured to extend to move the sealing sphere from the open position to the closed position.

B7. The stuffing box assembly of clause Bl , wherein the internal bore of the pollution control valve extends a length along a central longitudinal bore axis, the sealing pocket extending a length along a central longitudinal pocket axis that is angled at an oblique angle relative to the central longitudinal bore axis of the internal bore. B8. The stuffing box assembly of clause Bl , wherein a diameter of the sealing pocket of the pollution control valve is greater than a diameter of the internal bore.

Clause Set C:

C 1. A pollution control valve for a stuffing box of a pump system, said pollution control valve comprising:

a body having an internal bore configured to receive a drive shaft of the pump system, the body comprising a sealing pocket that intersects the internal bore;

a sealing member held within the sealing pocket of the body, the sealing member being moveable within the sealing pocket between an open position and a closed position that prevents fluid from flowing through the internal bore; and

an actuator configured to bias the sealing member toward the closed position, wherein the sealing member is held in the open position against the bias of the actuator by the presence of the drive shaft within the internal bore and the bias of the actuator is configured to move the sealing member from the open position to the closed position upon the drive shaft exiting the internal bore.

C2. The pollution control valve of clause CI , wherein the sealing member is a sphere. It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. Furthermore, invention(s) have been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention(s). Further, each independent feature or component of any given assembly may constitute an additional embodiment. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "clockwise" and "counterclockwise", "left" and right", "front" and "rear", "above" and "below" and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

When introducing elements of aspects of the disclosure or the examples thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. For example, in this specification, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of. A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised", "comprises", "having", "has", "includes", and "including" where they appear. The term "exemplary" is intended to mean "an example of." The phrase "one or more of the following: A, B, and C" means "at least one of A and/or at least one of B and/or at least one of C." Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112(f), unless and until such claim limitations expressly use the phrase "means for" followed by a statement of function void of further structure.

Although the terms "step" and/or "block" may be used herein to connote different elements of methods employed, the terms should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. The order of execution or performance of the operations in examples of the disclosure illustrated and described herein is not essential, unless otherwise specified. The operations may be performed in any order, unless otherwise specified, and examples of the disclosure may include additional or fewer operations than those disclosed herein. It is therefore contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation is within the scope of aspects of the disclosure.

Having described aspects of the disclosure in detail, it will be apparent that modifications and variations are possible without departing from the scope of aspects of the disclosure as defined in the appended claims. As various changes could be made in the above constructions, products, and methods without departing from the scope of aspects of the disclosure, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.