HK1216770B - Valve with removable seat - Google Patents

Description

Valves with removable seats

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority from U.S. Provisional Application No. 61/820,202, filed May 7, 2013, and U.S. Provisional Application No. 61/925,724, filed January 10, 2014, both of which are incorporated herein by reference.

Technical Field

The present invention relates to valves for use in high wear environments.

Background Art

In hydraulic fluid transfer valve applications, there are many different fluid media to consider, including, for example, water, various chemicals, and concentrated, highly abrasive fluids (commonly referred to as slurries). Slurries can have varying levels of solids content and particle sizes. Because slurries have higher levels of solids content than typical hydraulic fluids, they present unique operational difficulties in systems transporting slurries, such as increased wear rates on pipes and valves.

Because slurries increase the rate of wear on components, systems that typically transport slurries have a predetermined maintenance schedule to replace worn parts such as seals, valve seats, and other components that experience wear. This maintenance typically requires shutting down the affected hydraulic lines and resulting in a loss of production capacity.

Typical valves used in slurry applications are pinch valves and knife gate valves, which are specifically designed for the increased solids content of the fluid and the resulting increased wear on components. To maintain these types of valves, it is necessary to remove the entire valve or a large portion of the pipe attached to the valve, resulting in increased downtime of the production line and associated loss of revenue.

There is a clear need for components, such as valves, that can be maintained in a faster and more efficient manner to reduce production downtime and the accompanying loss of revenue.

Summary of the Invention

The present invention relates to a valve. In one exemplary embodiment, the valve includes a housing having an inlet and an outlet. A cavity is positioned within the housing between the inlet and the outlet. A first opening in the housing provides access to the cavity. A valve seat is positioned within the cavity and sealingly engages the housing. The valve seat is insertable into and removable from the cavity through the first opening. A valve closing member is mounted within the valve seat and is movable relative to the valve seat between an open position and a closed position in which the valve seat is sealingly engaged. A first actuator is mounted on the housing and is engageable with the valve seat to remove the valve seat and the valve closing member from the cavity through the first opening.

In another example, the valve may further include a second actuator mounted on the housing. The second actuator engages the valve closure member to move the valve closure member between an open and a closed position. In a specific example, the valve closure member includes a body rotatably mounted within the valve seat, and the body is rotatably movable between an open and a closed position. As an example, in this embodiment, the valve closure member includes a disc.

In another example embodiment, the first actuator can be separated from the valve seat and engage the valve closing member to move the valve closing member between open and closed positions. In a specific example, the valve closing member includes a gate slidably mounted within the valve seat, and the gate is slidably movable between open and closed positions. As another example, the gate can be pivotally attached to the first actuator or slidably attached to the first actuator.

As an example, the cavity may be defined by first and second walls positioned within the housing and oriented transverse to a flow axis extending from an inlet to an outlet. The first and second walls are in a spaced relationship with each other, each wall having a surface facing the valve seat and sealingly engaging the valve seat. In another embodiment, the valve seat includes first and second sealing surfaces positioned to face each other and define a slot therebetween. The valve closure member may include a gate slidably movable within the slot between an open and a closed position. In this example, the gate is oriented transverse to the flow axis and has first and second faces disposed oppositely that sealingly engage the first and second sealing surfaces of the valve seat, respectively.

As an example, the valve may further include a strap attachable to the gate to retain the valve seat to the gate, thereby attaching the valve seat to the actuator to facilitate its removal from the cavity. In an example embodiment, the first actuator includes a screw jack.

In certain example embodiments, the housing includes a first segment defining a first opening and a second segment attached to the first segment. The first and second segments are attached end-to-end to each other and define an inlet and an outlet and a flow axis extending therebetween. Furthermore, as an example, each of the first and second segments includes first and second tabs projecting outwardly from opposite ends thereof. Each tab has at least one hole for receiving a fastener to attach the segments to each other.

In another example embodiment, each of the first and second segments includes first and second arcuate protrusions positioned on opposite sides of the segment.The first and second arcuate protrusions surround the flow axis and extend radially toward the flow axis.

As another example, each of the first and second segments includes first and second grooves positioned on opposite sides of the segment, with each groove facing the flow axis. First and second gaskets are positioned within the first and second grooves, respectively. In one exemplary embodiment, the first and second grooves extend over abutting surfaces of first and second tabs of the first and second segments. The first and second gaskets also extend along the first and second grooves in the tabs.

In an example embodiment, the inlet has an inner diameter and the valve seat defines an orifice having an inner diameter that is smaller than the inner diameter of the inlet, thereby defining a sealing surface facing the inlet. The sealing surface may include at least one protrusion that extends toward the inlet. As another example, the outlet may have an inner diameter, and the valve seat may define an orifice having an inner diameter that is smaller than the inner diameter of the outlet, thereby defining a sealing surface facing the outlet. In an example embodiment, the sealing surface includes at least one protrusion that extends toward the outlet.

As an example, the valve may further include a second opening in the housing that provides access to the cavity. In certain example embodiments, the second opening is positioned opposite the first opening.

Another example further includes a sealing body that is attachable to the valve seat. When the valve seat is removed through the first opening, the sealing body can be moved into the cavity through the second opening. In an example embodiment, the sealing body includes first and second sealing surfaces that are disposed opposite each other and sealably engage the housing. In another example embodiment, the sealing body includes multiple parts that are removably attached to each other. For example, the sealing body can include a rectangular block.

As another example, the valve seat may include multiple independent parts that can be attached to each other. Additional examples may further include a pivot hinge mounted on the housing. In this example, the first actuator is mounted on the pivot hinge and can be pivotally moved thereon relative to the housing.

In another example embodiment, a valve includes a housing having an inlet and an outlet. The housing includes first and second sections. The first and second sections are attached end-to-end to each other and define the inlet and outlet and a flow axis extending therebetween. A cavity is positioned within the housing between the inlet and the outlet. A first opening is positioned in the first section and a second opening is positioned in the second section. The first and second openings provide access to the cavity. A valve seat is positioned within the cavity and sealingly engages the housing. The valve seat can be inserted into and removed from the cavity through one of the first and second openings. A valve closing member is mounted within the valve seat and is movable relative to the valve seat between an open position and a closed position in which it sealingly engages the valve seat. A first actuator is mounted on the housing and can engage the valve seat to insert and remove the valve seat and the valve closing member into and from the cavity through one of the first and second openings.

In certain examples, each of the first and second segments includes first and second tabs projecting outwardly from opposite ends thereof, each tab having at least one aperture for receiving a fastener to attach the segments to one another. In another example, each of the first and second segments includes first and second arcuate protrusions positioned on opposite sides of the segment. The first and second arcuate protrusions surround the flow axis and extend radially toward the flow axis.

In an example embodiment, each of the first and second segments includes a first and second groove positioned on opposite sides of the segment. In this example, each groove faces the flow axis. The first and second gaskets are positioned within the first and second grooves, respectively. In a specific example, the second opening is positioned opposite the first opening. As an example, the gate is pivotally attached to the first actuator. Another example embodiment further includes a second actuator mounted on the housing. The second actuator engages the valve closing member to move the valve closing member between an open and a closed position. As an example, the valve closing member includes a body rotatably mounted within the valve seat, the body being rotatably movable between an open and a closed position. In a specific example, the valve closing member includes a disc.

In an exemplary embodiment, the first actuator is separable from the valve seat to engage the valve closing member to move the valve closing member between an open and a closed position. As an example, the valve closing member includes a gate slidably mounted within the valve seat. The gate is slidably movable between the open and closed positions.

Example embodiments further include a sealing body that is attachable to the valve seat. When the valve seat is removed through the first opening, the sealing body can be moved into the cavity through the second opening. In certain examples, the sealing body includes first and second sealing surfaces that are disposed opposite each other and sealably engage the housing. In another example, the sealing body includes multiple sections that are removably attachable to each other. As an example, the sealing body can include a rectangular block.

In another example embodiment, the valve seat comprises a plurality of separate parts that are attachable to one another.

As an example, a pivot hinge is mounted on the housing. A first actuator is mounted on the pivot hinge and is pivotally movable relative to the housing. Another example embodiment of a valve includes a housing having an inlet and an outlet. The housing includes first and second segments. The first and second segments are attached end-to-end to each other and define the inlet and outlet and a flow axis extending therebetween. In this example, a cavity is positioned within the housing between the inlet and the outlet. A first opening is positioned in the first segment and provides access to the cavity. A valve seat is positioned within the cavity and sealingly engages the housing. The valve seat includes a first component positioned within the first segment and a second component positioned within the second segment. The first component of the valve seat can be inserted into and removed from the cavity through the first opening. A valve closing member is mounted within the valve seat and is movable relative to the valve seat between an open position and a closed position in which it sealingly engages the valve seat. The first actuator is mounted on the housing and is engageable with the first component of the valve seat to insert and remove the first component of the valve seat and the valve closing member from the cavity through the first opening.

In one exemplary embodiment, the cavity is defined by first and second walls positioned in the housing and oriented transversely to a flow axis extending from the inlet to the outlet. The first and second walls are in spaced relation to each other. Each wall has a surface that faces the valve seat and sealingly engages the valve seat.

In an example, the first part of the valve seat includes first and second sealing surfaces positioned facing each other and defining a slot therebetween. In an example embodiment, the valve closure member includes a gate slidably movable within the slot between open and closed positions. The gate is oriented transverse to the flow axis and has first and second oppositely disposed faces that sealingly engage the first and second sealing surfaces of the first part of the valve seat, respectively.

Example embodiments may further include a strap attachable to the gate to retain the valve seat to the gate, thereby attaching the valve seat to the actuator to facilitate removal thereof from the cavity.

The present invention also includes a method for removing a valve seat from a valve. The valve has a closure member that engages the valve seat. An actuator engages the valve closure member. An example method includes:

attaching the valve seat to the valve closure member;

Both the valve seat and the valve closure member are pulled away from the valve using an actuator that engages the valve closure member.

A method of replacing a valve seat is also contemplated. The valve has a closure member engageable with the valve seat and an actuator engaging the valve closure member. An example method includes:

engaging the valve seat with the closure member;

Both the valve seat and the valve closure member are moved into the valve using an actuator that engages the valve closure member.

The present invention further includes a method for replacing a valve seat in a valve using a barrier body. In a specific example, the method includes:

attaching the barrier body to the valve seat;

Pull the valve seat away from the valve and simultaneously pull the barrier body into the valve;

Disengage the valve seat from the blocking body;

Attach the new valve seat to the barrier body;

Insert the new valve seat into the valve while forcing the blocking body away from the valve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 shows an isometric view of an example valve embodiment according to the present invention;

2 and 3 show longitudinal cross-sectional views of a portion of the valve shown in FIG. 1 ;

2A and 2B show a portion of the valve of FIG. 1 in isolation;

FIG4 shows a cross-sectional view taken along line 4-4 of FIG2;

5 and 6 are isometric views showing an exemplary embodiment of a portion of a valve according to the present invention;

7-9 are partial cross-sectional isometric views illustrating an example method of replacing a valve seat according to the present invention;

FIG10 is a partial isometric cross-sectional view of an example embodiment of a valve seat according to the present invention; and

11 is a partial isometric cross-sectional view of an example embodiment of a valve seat and valve closing member according to the present invention.

DETAILED DESCRIPTION

FIG1 shows an example embodiment of a valve 10 according to the present invention. The valve 10 includes a housing 12 having an inlet 14 and an outlet 16. The housing 12 can be formed from a metal (such as rolled iron, cast iron, or steel), a composite (such as fiberglass), and a polymer (such as PVC (polyvinyl chloride)). The housing 12 includes a first segment 18 and a second segment 20 that are attached end-to-end to each other and thereby define the inlet 14, the outlet 16, and a flow axis 22 extending therebetween. In this example embodiment, the segments 18 and 20 have protruding tabs 24, each having one or more aligned holes 26 that receive fasteners 28 to attach the segments to each other. When used to connect grooved pipe elements (see FIG2 ), the segments will have arcuate protrusions 30 (also referred to as "keys") positioned on opposite sides 32 and 34 of the segments 18 and 20. The arcuate protrusion 30 surrounds and faces the flow axis 22 and extends radially toward the flow axis 22 , allowing it to engage a circumferential groove in the pipe element and provide a mechanical engagement to retain the pipe element to the valve 10 .

As shown in FIG. 2 , a cavity 36 is positioned within the housing 12 between the inlet 14 and the outlet 16 . A first opening 38 within the first section 18 provides access to the cavity 36 . A valve seat 40 is positioned within the cavity 36 . The valve seat 40 can advantageously be formed from a resilient, flexible material, such as a rubber compound or urethane. The valve seat can be inserted into the cavity 36 through the opening 38 and sealingly engage the housing. In this example embodiment, the sealing engagement between the valve seat 40 and the housing 12 is achieved by contact between oppositely facing surfaces 42 and 44 of the valve seat, which engage first and second housing walls 46 and 48 , respectively. Walls 46 and 48 are oriented transverse to the flow axis 22 and are in a spaced relationship with each other to define the cavity 36 . When inserted into the cavity 36 , the valve seat 40 is compressed between the walls 46 and 48 to achieve a seal at the engaging surfaces. Note that it may be advantageous to position protrusions 50 on surfaces 42 and 44 to ensure uniform compression, and therefore a fluid-tight seal, between valve seat 40 and housing 12 .

Inlet 14 and outlet 16 each have respective inner diameters 14a and 16a that are substantially aligned with an orifice 52 defined by the valve seat. Inlet 14, outlet 16, and orifice 52 collectively define flow axis 22 through valve 10. In the example shown, orifice 52 of valve seat 40 has an inner diameter 52a that is smaller than the inner diameters 14a and 16a of inlet 14 and outlet 16, respectively. This diameter difference creates two axial sealing surfaces: a sealing surface 54 facing inlet 14 and a sealing surface 56 facing outlet 16. As shown in Figures 2 and 3, axial sealing surfaces 54 and 56 engage the ends of tubular elements 58 and 60 coupled through valve 10. Compression between the ends of tubular elements 58 and 60 and axial sealing surfaces 54 and 56 is provided by the location of arcuate protrusions 30 and circumferential grooves 62 of the tubular elements. Axial projections 64, positioned on sealing surfaces 54 and 56, respectively, and extending toward inlet 14 and outlet 16, respectively, serve to ensure a uniform seal between tubular elements 58 and 60 and valve seat 40. Additional or alternative sealing between tubular elements 58 and 60 and the housing can be achieved by gaskets 66, which are positioned in corresponding grooves 68 and 70 in segments 18 and 20. Grooves 68 and 70 are positioned on opposing sides 32 and 34 of the segments and face toward flow axis 22. Gaskets 66 engage the segments and tubular elements to achieve a fluid-tight seal therebetween. As shown in Figures 2A, 2B, and 4, grooves 68 and 70 and gasket 66 may also extend along abutting surfaces 24a and 24b of lug 24. This sealing configuration is shown separated in Figure 2B to illustrate how seals 66 engage one another and form a complete sealing boundary, eliminating any potential leak paths between segments 18 and 20.

As shown in FIG3 , valve seat 40 includes first and second sealing surfaces 72 and 74 arranged in a spaced, facing relationship with each other to define a slot 76 . A valve closure member in the form of a gate 78 is slidably movable within slot 76 between a closed position (shown in FIG2 ) and an open position (shown in FIG3 ). In the closed position, gate 78 sealingly engages sealing surfaces 72 and 74 and blocks flow through orifice 52 , while the open position permits flow between inlet 14 and outlet 16 . Gate 78 can be made of metal (e.g., steel), a composite (such as fiberglass), and a polymer (such as HDPE (high-density polyethylene)). When in the closed position, gate 78 is in compressive engagement with sealing surfaces 72 and 74. To ensure a uniform seal between gate 78 and valve seat 40 , a circumferential protrusion 80 is advantageously positioned on surfaces 72 and 74 .

Movement of the gate 78 is achieved by an actuator, which in this example is a rising stem screw jack 82 mounted on the first section 18 of the housing 12 (see FIG1 ). Other types of actuators are also possible, such as pneumatic actuators, hydraulic actuators, and electric actuators. The shaft of the screw jack 82 is separated from the valve seat 40 to engage the gate 78, and rotation of the actuating wheel of the screw jack moves the screw jack shaft, which moves the gate within the slot 76 of the valve seat 40 between open and closed positions, as shown in FIG2 and 3 . The valve seat 40 is advantageously retained within the cavity 36 by a retaining plate 84 that is removably secured to the housing 12. Otherwise, when the gate 78 is pulled away from the housing 12, significant friction between the gate 78 and the sealing surfaces 72 and 74 (see FIG3 ) may cause the valve seat 40 to be removed from the cavity. However, the actuator (screw jack 82) can engage both the valve closing member (gate 78) and the valve seat 40 to intentionally remove both the gate and the valve seat from the cavity 36. This allows for easy replacement of a worn valve seat without removing the valve 10 from the pipe elements 58 and 60. Valve seat replacement can be accomplished by removing the retaining plate 84 to allow the valve seat 40 to move through the opening 38 in the segment 18. Actuating the screw jack 82 to withdraw the gate 78 from the slot 76 can instead remove the valve seat 40 from the cavity 36, as long as the friction between the gate and the valve seat is greater than the friction between the valve seat and the housing 12. However, it is advantageous to provide a mechanical engagement between the actuator 82 and the valve seat 40 to ensure the desired removal. To this end, as shown in Figures 1 and 4, a strip 86 is positioned to surround the valve seat 40 within the cavity 36. The strap 86 can be attached to the gate 78 using, for example, bolts 88 to provide a mechanical engagement, thereby allowing the valve seat 40 to be withdrawn from the cavity 36 along with the gate 78 using an actuator. As shown in FIG5 , to further facilitate valve seat replacement, an actuator (screw jack 82) can be mounted on a pivot hinge 90 to allow pivotal movement of the gate 78 and valve seat 40 for easy access. The worn valve seat 40 can then be removed from the gate 78 by loosening the strap 86, sliding the worn valve seat off the gate, sliding a new valve seat onto the gate, bolting the strap 86 onto the gate, rotating the screw jack 82 on the pivot hinge 90 to align the gate and valve seat with the opening 38 (see FIGS. 2 and 3 ), and then using the screw jack to force the new valve seat into the cavity 36. Once the valve seat is properly positioned within the cavity 36, the bolts 88 can be removed, and the retaining plate 84 can be reattached to the segment 18. In another embodiment shown in FIG6 , the gate 78 can be pivotally attached to an actuator, in this example, a screw jack 82. Still another embodiment is shown in FIG1 , in which the gate 78 is slidingly attached to the actuator (screw jack 82) using a “T-shaped” coupling 92, which allows both the gate 78 and valve seat 40 to be removed as an assembly when they are pulled away from the cavity 36. The assembly slides along an axis perpendicular to the flow axis 22 to allow for quick and convenient replacement of a worn valve seat.

In another valve embodiment 94 shown in FIG7 , replacement of a worn valve seat 40 is further facilitated by the use of a sealing body 96. Sealing body 96 allows replacement of valve seat 40 without interrupting fluid flow to valve 94. Valve 94 has a second opening 98 positioned in second segment 20, opposite first opening 38. Second opening 98 provides access to cavity 36 and allows sealing body 96 to be removably attached to valve seat 40. In this exemplary embodiment, sealing body 96 comprises a rectangular block 100 having oppositely disposed sealing surfaces 102 and 104. As shown in FIG8 , when sealing body 96 is temporarily attached to valve seat 40 and the valve seat is pulled out of cavity 36 by actuator 82 through opening 38 in first segment 18, sealing body 98 is pulled into cavity 36 through second opening 98 in second segment 20. Sealing surfaces 102 and 104 of block 100 sealingly engage housing 12, i.e., walls 46 and 48, thereby closing valve 94. The valve seat 40 is then released from the sealing body 96 and can be replaced as described above, with the additional step of attaching the valve seat 40 to the sealing body 96. When the new valve seat 40 is inserted into the cavity 36 through the opening 38 in the segment 18, the sealing body 96 (in this example, the block 100) is forced out of the cavity through the opening 98 in the segment 20. The sealing body can then be disengaged from the new valve seat 40. The temporary attachment of the valve seat 40 to the sealing body 98 can be achieved by, for example, friction of contact surfaces of mutually engaging parts, aligned holes and pins, a spring-biased latch, or a dovetail joint. It can also be advantageous for the sealing body 96 to include a plurality of interlocking portions 106 that are removably attached to each other, as shown in Figure 9. This allows the sealing body to be assembled and pulled into the cavity 36 one portion at a time, and can be used when, for example, space is not available to accommodate a full-sized block 100. The portions 106 may be temporarily joined to one another using a dovetail joint (as shown) or using friction of contacting surfaces of interengaging components, spring biased latches, and aligned holes and pins, to name a few examples.

As shown in FIG. 10 , the valve seat 108 can be formed from multiple separate parts that cooperate with one another. In this example, the valve seat 108 includes first and second parts 110 and 112, which can be positioned within the cavity 36 of the example valve embodiment 10, rather than the valve seat 40 (see FIG. 2 ) and valve embodiment 94 (see FIG. 7 ). The first and second parts 110, 112 include first and second sealing surfaces 114 and 116 that are disposed opposite one another and can sealably engage the housing 12. The first and second parts 110 and 112 further include sealing surfaces 118 and 120 that are positioned facing one another and define a notch 122 therebetween. The notch receives the gate 78 in sealing relationship.

While the illustrated example embodiment relates to a gate valve, the present invention is also applicable to other types of valves. As shown in FIG11 , a body 124 is rotatably mounted within a valve seat 126 . The body can rotate about an axis 128 between an open position and a closed position in which it sealingly engages the valve seat 126 . In this example, the valve closing member comprises a disc 130 , a feature of the well-known "butterfly" valve. As with the valve seat 40 described above, when the disc 130 is in the closed position, the valve seat 126 can be inserted into and removed from the cavity 36 (see FIG1 ) of the housing 12 through the opening 38 (see FIG2 ) described above. Because the valve closing member is actuated by rotation about the axis 128 , the actuator (screw jack 82 ) used to pull the valve seat 126 away from the housing can also be used to actuate the valve. Therefore, a second actuator (e.g., a handle 132 ) is mounted on the housing to rotate the disc 130 . While a simple handle is shown, the second actuator could be a motorized gear train or other form of power actuation.

Claims (61)

1. A valve, comprising: A shell having an inlet and an outlet; The cavity is positioned within the housing between the inlet and the outlet, and a first opening in the housing provides passageway to the cavity. A valve seat, which is positioned within the cavity and sealably engages with the housing, can be inserted into and removed from the cavity through the first opening; A valve closing component, which is mounted within the valve seat and movable relative to the valve seat between an open position and a closed position that seals against the valve seat; A first actuator, which is mounted on the housing and engageable with the valve seat, removes the valve seat and the valve closing component from the cavity through the first opening; The first actuator causes the valve closing component to move within the valve seat between the open position and the closed position. 2. The valve according to claim 1, further comprising a second actuator mounted on the housing, the second actuator engaging with the valve closing member to move the valve closing member between the open position and the closed position. 3. The valve according to claim 2, wherein the valve closing component includes a body rotatably mounted within the valve seat, the body being rotatably movable between the open position and the closed position. 4. The valve according to claim 3, wherein the valve closing component comprises a disc. 5. The valve according to claim 1, wherein the first actuator is separable from the valve seat to engage with the valve closing member, thereby moving the valve closing member between the open position and the closed position. 6. The valve according to claim 5, wherein the valve closing component includes a gate slidably mounted within the valve seat, the gate being slidably movable between the open position and the closed position. 7. The valve according to claim 6, wherein the gate is pivotally attached to the first actuator. 8. The valve according to claim 6, wherein the gate is slidably attached to the first actuator. 9. The valve according to claim 1, wherein the cavity is defined by a first wall and a second wall, the first wall and the second wall being positioned within the housing and oriented transversely to a flow axis extending from the inlet to the outlet, the first wall and the second wall being spaced apart from each other, each of the walls having a surface facing the valve seat and sealingly engaging with the valve seat. 10. The valve according to claim 9, characterized in that: The valve seat includes a first sealing surface and a second sealing surface, which are positioned facing each other and define a slot between them; The valve closing component includes a gate that is slidably movable within the slot between the open and closed positions. The gate is oriented transversely to the flow axis and has a first surface and a second surface arranged opposite to each other, which respectively sealably engage the first sealing surface and the second sealing surface of the valve seat. 11. The valve of claim 10, further comprising a strip that can be attached to the gate to hold the valve seat to the gate, thereby attaching the valve seat to the actuator to facilitate its removal from the cavity. 12. The valve according to claim 11, wherein the first actuator comprises a screw jack. 13. The valve of claim 1, wherein the housing comprises a first segment defining the first opening and a second segment attached to the first segment, the first segment and the second segment being attached end-to-end to each other and defining the inlet and the outlet and a flow axis extending therebetween. 14. The valve according to claim 13, wherein each of the first segment and the second segment includes a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the segment, the first arcuate protrusion and the second arcuate protrusion surrounding the flow axis and extending radially toward the flow axis. 15. The valve according to claim 13, wherein each of the first segment and the second segment includes a first lug and a second lug projecting outward from their opposite ends, each lug having at least one hole for receiving a fastener to attach the segments to each other. 16. The valve according to claim 15, wherein each of the first segment and the second segment comprises: A first groove and a second groove are positioned on opposite sides of the segment, each of the grooves facing the flow axis; The first gasket and the second gasket are respectively positioned in the first groove and the second groove. 17. The valve according to claim 16, wherein the first groove and the second groove extend on the junction surface of the first lug and the second lug of the first segment and the second segment, and the first gasket and the second gasket extend along the first groove and the second groove in the first lug and the second lug. 18. The valve according to claim 13, characterized in that: The inlet has an inner diameter; The valve seat defines an orifice having an inner diameter smaller than that of the inlet, thereby defining a sealing surface facing the inlet. 19. The valve according to claim 18, wherein the sealing surface includes at least one protrusion extending toward the inlet. 20. The valve according to claim 13, characterized in that: The outlet has an inner diameter; The valve seat defines an orifice having an inner diameter smaller than that of the outlet, thereby defining a sealing surface facing the outlet. 21. The valve according to claim 20, wherein the sealing surface includes at least one protrusion extending toward the outlet. 22. The valve according to claim 1, characterized in that it further comprises: A second opening in the housing provides access to the cavity. 23. The valve according to claim 22, wherein the second opening is positioned opposite to the first opening. 24. The valve according to claim 22, further comprising a sealing body that can be attached to the valve seat, wherein when the valve seat is removed through the first opening, the sealing body can be moved into the cavity through the second opening. 25. The valve according to claim 22, wherein the sealing body comprises: The first sealing surface and the second sealing surface are arranged opposite to each other and are sealably engaged with the housing. 26. The valve according to claim 24, wherein the sealing body comprises a plurality of portions which are removably attached to each other. 27. The valve according to claim 24, wherein the sealing body comprises a rectangular block. 28. The valve according to claim 1, wherein the valve seat comprises a plurality of independent parts which can be attached to each other. 29. The valve according to claim 1, characterized in that it further comprises: A pivot hinge is mounted on the housing, and the first actuator is mounted on the pivot hinge and is pivotally movable thereon relative to the housing. 30. A valve comprising: A housing having an inlet and an outlet, the housing comprising a first segment and a second segment, the first segment and the second segment being attached end-to-end to each other and defining the inlet and the outlet and a flow axis extending therebetween; A cavity located within the housing between the inlet and the outlet, a first opening located in the first segment, and a second opening located in the second segment, the first and second openings providing passage to the cavity; A valve seat, which is positioned within the cavity and sealably engages with the housing, can be inserted into and removed from the cavity through one of the first and second openings; A valve closing component, which is mounted within the valve seat and movable relative to the valve seat between an open position and a closed position that seals against the valve seat; and A first actuator, mounted on the housing and engageable with the valve seat, is used to insert and remove the valve seat and the valve closing component from the cavity through one of the first and second openings. The first actuator causes the valve closing component to move within the valve seat between the open position and the closed position. 31. The valve according to claim 30, wherein each of the first segment and the second segment includes a first lug and a second lug projecting outward from their opposite ends, each lug having at least one hole for receiving a fastener to attach the segments to each other. 32. The valve according to claim 30, wherein each of the first segment and the second segment includes a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the segment, the first arcuate protrusion and the second arcuate protrusion surrounding the flow axis and extending radially toward the flow axis. 33. The valve according to claim 30, wherein each of the first segment and the second segment comprises: A first groove and a second groove are positioned on opposite sides of the segment, each of the grooves facing the flow axis; The first gasket and the second gasket are respectively positioned in the first groove and the second groove. 34. The valve according to claim 30, wherein the second opening is positioned opposite to the first opening. 35. The valve of claim 30, further comprising a second actuator mounted on the housing, the second actuator engaging with the valve closing member to move the valve closing member between the open position and the closed position. 36. The valve according to claim 35, wherein the valve closing component includes a body rotatably mounted within the valve seat, the body being rotatably movable between the open position and the closed position. 37. The valve according to claim 36, wherein the valve closing component comprises a disc. 38. The valve according to claim 30, wherein the first actuator is separable from the valve seat to engage with the valve closing member to move the valve closing member between the open position and the closed position. 39. The valve according to claim 38, wherein the valve closing component includes a gate slidably mounted within the valve seat, the gate being slidably movable between the open position and the closed position. 40. The valve according to claim 39, wherein the gate is pivotally attached to the first actuator. 41. The valve according to claim 30, further comprising a sealing body that can be attached to the valve seat, wherein when the valve seat is removed through the first opening, the sealing body can be moved into the cavity through the second opening. 42. The valve according to claim 41, wherein the sealing body comprises: The first sealing surface and the second sealing surface are arranged opposite to each other and are sealably engaged with the housing. 43. The valve according to claim 41, wherein the sealing body comprises a plurality of portions which are removably attached to each other. 44. The valve according to claim 41, wherein the sealing body comprises a rectangular block. 45. The valve according to claim 30, wherein the valve seat comprises a plurality of independent parts which can be attached to each other. 46. The valve according to claim 30, characterized in that it further comprises: A pivot hinge is mounted on the housing, and the first actuator is mounted on the pivot hinge and is pivotally movable thereon relative to the housing. 47. A valve comprising: A housing having an inlet and an outlet, the housing comprising a first segment and a second segment, the first segment and the second segment being attached end-to-end to each other and defining the inlet and the outlet and a flow axis extending therebetween; A cavity located within the housing between the inlet and the outlet, with a first opening located in the first segment and providing passageway to the cavity; A valve seat, positioned within the cavity and sealingly engaging the housing, the valve seat comprising a first part positioned within a first segment and a second part positioned within a second segment, the first part of the valve seat being insertable into and removable from the cavity through the first opening; A valve closing component, which is mounted within the valve seat and movable relative to the valve seat between an open position and a closed position that seals against the valve seat; and A first actuator, mounted on the housing and engageable with the first part of the valve seat, is used to insert the first part of the valve seat and the valve closing component into the cavity and remove the first part of the valve seat and the valve closing component from the cavity through the first opening. The first actuator causes the valve closing component to move within the valve seat between the open position and the closed position. 48. The valve according to claim 47, wherein the cavity is defined by a first wall and a second wall, the first wall and the second wall being positioned within the housing and oriented transversely to a flow axis extending from the inlet to the outlet, the first wall and the second wall being spaced apart from each other, each of the walls having a surface facing the valve seat and sealingly engaging with the valve seat. 49. The valve according to claim 48, characterized in that: The first part of the valve seat includes a first sealing surface and a second sealing surface, which are positioned facing each other and define a slot between them; The valve closing component includes a gate that is slidably movable within the slot between the open and closed positions. The gate is oriented transversely to the flow axis and has a first surface and a second surface arranged opposite to each other, which respectively sealably engage the first sealing surface and the second sealing surface of the first part of the valve seat. 50. The valve of claim 49, further comprising a strip that can be attached to the gate to hold the valve seat to the gate, thereby attaching the valve seat to the actuator to facilitate its removal from the cavity. 51. The valve according to claim 47, wherein each of the first segment and the second segment includes a first lug and a second lug projecting outward from their opposite ends, each lug having at least one hole for receiving a fastener to attach the segments to each other. 52. The valve according to claim 47, wherein each of the first segment and the second segment includes a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the segment, the first arcuate protrusion and the second arcuate protrusion surrounding the flow axis and extending radially toward the flow axis. 53. The valve according to claim 47, wherein each of the first segment and the second segment comprises: A first groove and a second groove are positioned on opposite sides of the segment, each of the grooves facing the flow axis; The first gasket and the second gasket are respectively positioned in the first groove and the second groove. 54. The valve according to claim 47, characterized in that: The inlet has an inner diameter; The first part of the valve seat defines an orifice having an inner diameter smaller than the inner diameter of the inlet, thereby defining a sealing surface facing the inlet. 55. The valve according to claim 54, wherein the sealing surface includes at least one protrusion extending toward the inlet. 56. The valve according to claim 47, characterized in that: The outlet has an inner diameter; The first part of the valve seat defines an orifice having an inner diameter smaller than the inner diameter of the outlet, thereby defining a sealing surface facing the outlet. 57. The valve according to claim 56, wherein the sealing surface includes at least one protrusion extending toward the outlet. 58. The valve according to claim 47, wherein the first actuator comprises a screw jack. 59. A method for removing a valve seat from a valve according to any one of claims 1-58, the valve having a valve closing member engaging the valve seat and an actuator engaging the valve closing member, the method comprising: Attach the valve seat to the valve closing component; The actuator that engages the valve closing component is used to pull both the valve seat and the valve closing component away from the valve. 60. A method for replacing a valve seat in a valve according to any one of claims 1-58, the valve having a valve closing member engageable with the valve seat and an actuator engaging the valve closing member, the method comprising: The valve seat engages with the closing component; The actuator that engages the valve closing component is used to move both the valve seat and the valve closing component into the valve. 61. A method for replacing a valve seat in a valve according to any one of claims 1-58 using a blocking body, the method comprising: Attach the blocking body to the valve seat; Pull the valve seat away from the valve, and at the same time pull the blocking body into the valve; Disconnect the valve seat from the blocking body; Attach the new valve seat to the blocking body; The new valve seat is inserted into the valve, while simultaneously forcing the blocking body away from the valve.