Fluid flow control valve with bi-directional shutoff

A valve, comprising:

• a housing having an inlet and an outlet in fluid communication with a bore
• therethrough, the bore defining a primary fluid flowpath;
• a seal assembly mounted proximate to a ball element such that the ball element moves in a rotary motion relative to the seal assembly to engage the seal assembly during the opening and closing of the valve, the seal assembly including a secondary flowpath therethrough;
• and
• a first and a second elastic sealing ring impeding the flow through the secondary flowpath.

A method of operating a valve, comprising:

• providing a valve body having an inlet and an outlet forming a primary flowpath;
• eccentrically mounting a ball element relative the valve body, between the inlet and the outlet;
• biasing a seal assembly, the seal assembly including a main seal and a bi-directional seal, such that the main seal provides a seal against the ball element to impede flow through the primary flowpath during the opening and closing of the valve and the bi-directional seal provides a seal against a secondary flowpath within the seal assembly;
• providing a first gap, disposed between the main seal and a seal housing
• measuring a height of the first gap thereby controlling an angle of engagement between the ball element and the main seal;
• and
• rotating the ball element from a open position to a closed position.

A method of operating a valve, comprising:

• providing a valve body having an inlet, an outlet and a seal assembly, wherein the seal assembly comprises a main seal, a seal housing, and a bi-directional seal such that the bi-directional seal substantially impedes fluid flow through a flowpath defined between the main seal and the seal housing;
• biasing the main seal toward a ball element;
• eccentrically mounting the ball element in the valve body such that the ball element rotatably engages the main seal;
• and
• measuring a gap between the seal housing and the main seal to insure proper tolerances, the gap being accessible from an exterior surface of the valve.

A method of operating a valve, comprising:

• providing a valve body having an inlet, an outlet and a seal assembly, the seal assembly including a main seal and a bi-directional seal, such that the main seal provides a seal to impede flow through a primary flowpath during the opening and closing of the valve and the bi-directional seal provides a seal against a secondary flowpath within the seal assembly;
• biasing the main seal toward a ball element;
• eccentrically mounting the ball element in the valve body such that the ball element rotatably engages the main seal during valve operation;
• and
• limiting the engagement of the main seal with the ball element, while rotating the ball element with respect to the seal assembly from a closed to an open position by providing a calculated stop for the main seal.