Seal carriers for ball valves, ball valve assemblies including such seal carriers, and related methods
A seal carrier for a ball valve includes a carrier body to be located between a ball and a portion of a valve body. The carrier body may have an annular channel for carrying a ring seal in a side to be located proximate the ball. A spring is located at a peripheral portion of the carrier body. An end portion of the spring is configured to abut against the portion of the valve body, and the spring is configured to provide a compressive force between the portion of the valve body and the ball in a direction parallel with the direction of fluid flow through the ball valve assembly. A ball valve assembly may include such seal carriers. Methods of forming such seal carriers are also included.
1. A seal carrier for a ball valve assembly, comprising:
a carrier body configured to be located between a ball of the ball valve assembly and a portion of a valve body, the carrier body comprising an annular channel in a side of the carrier body to be located proximate the ball, the annular channel carrying a first ring seal;
a flow path extending through a central region of the carrier body; and
a spring located at a peripheral portion of the carrier body, wherein the spring is formed of a section of the carrier body or is a separate piece attached to the carrier body by one of welding and brazing, an end portion of the spring including a recess carrying a second ring seal configured to abut against the portion of the valve body;
wherein the seal carrier is configured to transmit the compressive force of the spring directly to the first ring seal in a manner to force the first ring seal into sealing engagement with the ball in a direction parallel with the direction of fluid flow through the valve body, and transmit the compressive force of the spring directly to the end portion of the spring in a manner to force the second ring seal into sealing engagement with the valve body, the seal carrier inhibiting fluid ingress between the portion of the valve body and the end portion of the spring and inhibiting fluid ingress between the seal carrier and the ball;
wherein the seal carrier and spring do not comprise surfaces in slidable contact with each other.
2. The seal carrier of claim 1 , wherein the spring is an accordion spring.
3. The seal carrier of claim 2 , further comprising a layer of coating material disposed over the spring.
4. The seal carrier of claim 2 , further comprising an annular, bellows-type sheet welded to a radially-inward portion of the spring to inhibit formation of deposits or ingress of particulate matter between folds of the spring.
5. A ball valve assembly, comprising:
a valve body having a ball therein;
a seal carrier mounted within the valve body between the ball and a portion of the valve body, the seal carrier comprising:
a carrier body having a flow path extending therethrough;
a spring located at a peripheral portion of the carrier body, wherein the spring is formed of a section of the carrier body or is a separate piece attached to the carrier body by one of welding and brazing, the spring configured to provide a compressive force between the portion of the valve body and the ball in a direction parallel with the direction of fluid flow through the valve body;
a first ring seal located directly between the seal carrier and the ball, wherein the first ring seal is forced into sealing engagement with the ball by the compressive force of the spring; and
a second ring seal carried in a recess in an end portion of the spring, the second ring seal abutting against the portion of the valve body to inhibit ingress of fluid between the portion of the valve body and the end portion of the spring
the seal carrier and first and second ring seals thereby forming a system configured to inhibit fluid ingress between the portion of the valve body and the end portion of the spring and inhibit fluid ingress between the seal carrier and the ball, without surfaces of the seal carrier in slidable contact with each other.
6. The ball valve assembly of claim 5 , wherein the spring is an accordion spring.
7. The ball valve assembly of claim 5 , wherein no structural components of the ball valve assembly are disposed between any folds of the spring.
8. The ball valve assembly of claim 5 , wherein the second ring seal is forced into sealing engagement with the portion of the valve body by the compressive force of the spring.
9. The ball valve assembly of claim 5 , wherein the spring is formed of one of a metal and a metal alloy that is resistant to a loss of spring force caused by temperature cycling.
10. The ball valve assembly of claim 5 , further comprising:
a second seal carrier mounted within the valve body on a side of the ball opposite the seal carrier, wherein the second seal carrier is mounted between the ball and a second portion of the valve body;
a third seal ring located directly between the second seal carrier and the ball, wherein the third ring seal is forced into sealing engagement with the ball by the compressive force of a spring of the second seal carrier; and
a fourth ring seal located between an end portion of the spring of the second seal carrier and the second portion of the valve body
the second seal carrier and third and fourth ring seals thereby forming a system on the side of the ball opposite the seal carrier configured to inhibit fluid ingress between the portion of the valve body and the end portion of the spring and inhibit fluid ingress between the second seal carrier and the ball.
11. A method of forming a seal carrier for a ball valve assembly, comprising:
providing a carrier body configured to be located between a ball of the ball valve assembly and a portion of a valve body extending transverse to the direction of fluid flow through the ball valve assembly;
forming an annular channel carrying a ring seal in a side of the carrier body to be located proximate the ball;
forming a flow path through a central region of the carrier body;
providing a spring at a peripheral portion of the carrier body, wherein the spring is formed of a section of the carrier body or is a separate piece attached to the carrier body by one of welding and brazing, wherein an end portion of the spring includes a recess carrying a second ring seal configured to abut against the portion of the valve body, and the spring is configured to provide a compressive force between the portion of the valve body and the ball in a direction parallel with the direction of fluid flow through the valve body in a manner to force the ring seal into sealing engagement with the ball and to inhibit ingress of fluid between the portion of the valve body and the second ring seal at the end portion of the spring
the seal carrier and first and second ring seals thereby forming a system configured to inhibit fluid ingress between the portion of the valve body and the end portion of the spring and inhibit fluid ingress between the seal carrier and the ball, without surfaces of the seal carrier and spring in slidable contact with each other.