Sleeve seal assembly and rotary valve having sleeve seal assembly

A fluid flow control device, comprising:

• a valve body defining an inlet portion, an outlet portion, and a fluid flow path extending between the inlet portion and the outlet portion;
• a control assembly comprising a ball element disposed within the valve body and rotatable between an open position and a closed position;
• an internal recess defined by the valve body at a location downstream from the inlet portion;
• a seal assembly disposed within the internal recess of the valve body and comprising a sleeve seal, a retaining device, a biasing element, and a C-seal, the sleeve seal axially movable along a direction of the flow path and adapted to be sealingly engaged by the ball element when the ball element occupies the closed position, the sleeve seal including a sealing leg portion in sliding contact with the retaining device and a biased leg portion in sliding contact with the valve body, the retaining device attached to the valve body adjacent to the internal recess and between at least a portion of the sleeve seal and the ball element to limit displacement of the sleeve seal in the valve body toward the ball element, the biasing element having a first end seated against a portion of the valve body and a second end seated against the biased leg portion of the sleeve seal, the biasing element configured to bias the biased leg portion toward the ball element, and the C-seal disposed between the sleeve seal and one of the retaining device and the valve body to prevent leakage when the ball element is in the closed position.

A seal assembly for a rotary ball valve, the seal assembly comprising:

• a sleeve seal adapted to be mounted adjacent an inlet portion of a rotary valve body and to be engaged by a ball element of the rotary ball valve when the ball element occupies a closed position, the sleeve seal including a sealing leg portion and a biased leg portion adapted to be in sliding contact with the rotary valve body;
• a retaining device adapted to be attached to the rotary valve body between at least a portion of the sleeve seal and the rotary valve body to retain the sleeve seal in the rotary valve body, the sealing leg portion of the sleeve seal being in sliding contact with the retaining device, and the retaining device defining an annular channel;
• a biasing element having a first end adapted to be seated against a portion of the rotary valve body and a second end adapted to be seated against the biased leg portion of the sleeve seal, the biasing element adapted to bias the biased leg portion toward the ball element;
• a first sealing element disposed within the annular channel of the retaining device and adapted to provide a fluid tight seal between the sleeve seal and the retaining device to prevent leakage when the ball element is in the closed position.