Valve seat with seal for use with valve element in valve assembly

A valve seat for use in a valve assembly, the valve assembly including a valve body defining a fluid inlet in fluid communication with a fluid outlet, the valve body having an inner body surface defining an interior chamber extending between the fluid inlet and the fluid outlet;

• a control shaft disposed in the interior chamber and coupled to the valve body for rotational movement relative to the valve body;
• and a valve element disposed in the interior chamber and coupled to the control shaft for movement in conjunction with the control shaft relative to the valve body through a range of positions between and including a closed position and an open position with the valve element having an outer surface defining an outer radial diameter,
• said valve seat comprising:
• a cylindrical body portion having an inner seat surface and an opposing outer seat surface, said cylindrical body portion defining a clearance hole extending from said inner seat surface and said opposing outer seat surface for receipt of said control shaft, said inner seat surface defining an inner radial diameter, and
• at least one seal disposed around said opposing outer seat surface sealingly coupling said valve seat to said valve body,
• wherein said cylindrical body portion is formed from a polymeric material which maintains dimensional stability at temperatures ranging from −40° C. to 66° C. and which is configured to self-adjust said inner radial diameter to correspond to the outer radial diameter of the valve element to maintain a portion of said inner seat surface in contact with the outer valve surface of the valve element through said range of positions.

A method for controlling the flow of fluid through a valve assembly in a linear flow pattern, the valve assembly including a valve body defining a fluid inlet in fluid communication with a fluid outlet, the valve body having an inner body surface defining an interior chamber extending between the fluid inlet and the fluid outlet;

• a control shaft disposed in the interior chamber and coupled to the valve body for rotational movement relative to the valve body;
• and a valve element disposed in the interior chamber and coupled to the control shaft for movement in conjunction with the control shaft relative to the valve body through a range of positions between and including a closed position and an open position with the valve element having an outer surface defining an outer radial diameter;
• and a valve seat comprising a cylindrical body portion having an inner seat surface and an opposing outer seat surface, the cylindrical body portion defining a clearance hole extending from the inner seat surface and the opposing outer seat surface for receipt of the control shaft, the inner seat surface defining an inner radial diameter, the valve seat also comprising at least one seal disposed around said opposing outer seat surface for sealingly coupling said valve seat to the valve body, wherein the cylindrical body portion is formed from a polymeric material which maintains dimensional stability at temperatures ranging from −40° C. to 66° C.,
• said method comprising:
• moving the valve element from a first position of the range of positions to a second position of the range of positions to achieve a desired flow of fluid in the interior chamber between the valve element and the valve seat and between the fluid inlet and fluid outlet, wherein the inner radial diameter of the valve seat is self-adjusted during said moving of the valve element to maintain a portion of the inner seat surface in contact with the outer surface of the valve element as the valve element moves through the range of positions between the closed and open positions.