Valve seats, valve assemblies, and related methods
Valve seats may include an insert and an outer housing. The insert may comprise a first material and the outer housing may comprise a second material. The second material of the outer housing may exhibit a hardness that is greater than a hardness of the first material of the insert. Valve assemblies and related method may include valve seats.
1. A valve seat comprising:
an insert comprising a first polymer material, the insert configured to be positioned proximate and to contact a valve member and define a portion of a seal between the valve member and a valve body in which the valve member is positioned, the insert having a primary seating surface to define the portion of the seal with the valve member; and
an outer housing comprising a second polymer material, the outer housing defining an axially open and unobstructed recess, wherein at least a portion of the insert is configured to be positioned within the outer housing in the axially open and unobstructed recess, the outer housing configured to be positioned between the insert and the valve body to define another portion of the seal between the valve member and the valve body, the outer housing having a secondary seating surface to define the another portion of the seal with the valve member, wherein the second polymer material of the outer housing exhibits a hardness that is greater than a hardness of the first polymer material of the insert.
2. The valve seat of claim 1 , wherein an entirety of the insert comprises the first polymer material, and wherein an entirety of the outer housing comprises the second polymer material.
3. The valve seat of claim 1 , wherein an entirety of an axial extent of the insert is received within an axial extent of a portion of the outer housing defining the recess.
4. The valve seat of claim 1 , wherein the first polymer material has a Rockwell R scale hardness less than 100 and greater than 50.
5. The valve seat of claim 4 , wherein the second polymer material has a Rockwell R scale hardness greater than 100 and less than 150.
6. The valve seat of claim 1 , further comprising an outer body seal positioned at an outer lateral extent of the outer housing, the outer body seal configured to at least partially define another portion of the seal between the valve member and the valve body.
7. The valve seat of claim 6 , wherein the outer body seal and the insert comprise substantially similar materials configured to elastically deform at substantially the same level of force.
8. The valve seat of claim 6 , wherein the outer housing comprises an annular groove configured to receive a portion of the outer body seal in the annular groove.
9. The valve seat of claim 1 , wherein the insert comprises a rear axial wall and a radially outer wall, wherein the insert only contacts the outer housing at the rear axial wall and the radially outer wall of the insert.
10. The valve seat of claim 9 , wherein the outer housing comprises a forward axial inner wall and a radially inner wall, the forward axial inner wall of the outer housing contacting an entirety of the rear axial wall of the insert and the radially inner wall of the outer housing contacting an entirety of the radially outer wall of the insert.
11. The valve seat of claim 9 , wherein the rear axial wall and the radially outer wall of the insert comprise a gradual transition at an interface between the rear axial wall and the radially outer wall.
12. A valve assembly comprising: a valve body comprising at least one port; a valve member positioned within the valve body and configured to selectively enable fluid to pass through the at least one port in the valve body; and at least one valve seat comprising: a seat member comprising a polymer material, the seat member positioned adjacent and configured to seal against the valve member; and a support member comprising another polymer material, the support member positioned between the seat member and the valve body and configured to seal against the valve body, wherein a radial extent and an axial extent of the seat member are received within a radial extent and an axial extent of a recess defined by the support member, and wherein in an initial state, an axial end surface and a radially outer surface of the support member border and contact the valve body.
13. The valve assembly of claim 12 , wherein the valve assembly comprises a ball valve and the valve member comprises a rotatable ball positioned in the valve body.
14. The valve assembly of claim 12 , wherein the another polymer material of the support member exhibits a hardness that is greater than a hardness of the polymer material of the seat member.
15. The valve assembly of claim 14 , wherein the seat member has a Rockwell R scale hardness less than 70 and greater than 50.
16. The valve assembly of claim 15 , wherein: the seat member comprises a material selected from the group consisting of tetrafluoroethylene, polytetrafluoroethylene, modified polytetrafluoroethylene, and reinforced polytetrafluoroethylene; and the support member comprises a material selected from the group consisting of nylon plastics, polyaryletherketone, polyoxymethylene, carbon filled PTFE, and polychlorotrifluoroethylene.
17. The valve assembly of claim 12 , wherein the support member comprises a separate body sealing member configured to contact and seal against the valve body.
18. The valve assembly of claim 17 , wherein the body sealing member comprises a material having a hardness that is substantially similar to a hardness of the polymer material of the seat member.
19. A method of providing a seal in a ball valve, the method comprising: positioning a first section of a seat comprising a first polymer material adjacent a movable ball of the ball valve; positioning a second section of the seat comprising a second polymer material adjacent a body of the ball valve, the first section of the seat being received in an axially unobstructed recess defined in the second section of the seat; forcing the movable ball into the seat to form a seal between the movable ball and the valve body with the seat, and defining the seal between the movable ball and the valve body with the first section having a primary seating surface and with the second section having a secondary seating surface.
20. The method of claim 19 , further comprising deforming a portion of the second section of the seat comprising a third polymer material into the valve body.