Bi-directional pressure balanced valve

Claim 2

A valve assembly comprising: a body having two flow ports fluidly connected by a cylindriCal valve control chamber; a first annular valve seat on the body between the control chamber and one of the flow ports; a cylindrical valve closure disc in the chamber having a first seating surface on the lower portion thereof and axially movable therewithin between an open position wherein said first seating surface is spaced from the first valve seat to permit fluid flow between the ports and a closed position wherein said seating surface sealingly engages said first annular valve seat to prevent flow past the seat between the ports; a cylindrical first bore coaxially formed in the upper portion of the closure disc; a hollow member rigidly coaxially connected at a lower end to the closure disc, said hollow member having an enlarged downwardly opening second bore at the lower end adjacent the first bore and defining therewith an annular chamber with axially spaced surfaces; means carried by the hollow member in axially spaced relationship to said closure disc, said means slidably engaging the surfaces of said control chamber and guiding said closure disc for axial movement in said control chamber between said positions; an axial fluid passage through said closure disc connecting said bores with said one of the flow ports and defining a supplemental flow path between said one of said flow ports and said control chamber; a second annular valve seat on the closure disc between the fluid passage and coaxial with the first bore; a cylindrical check valve having an outer surface slidably guidably supported in the first bore, said check valve having a second seating surface thereon engageable with the second valve seat and normally adapted to open or close said fluid passage through said closure disc in response to pressure changes in said ports and said control chamber; a valve stem; means for moving said valve stem in opposite directions; an actuator member slidably supported in the second bore and connected to said valve stem for lost motion movement between said axially spaced surfaces; fluid passages associated with the check valve and the actuator member for providing fluid communication therethrough between said one of said ports and the control chamber; end means projecting from the actuator member freely slidably associated with the check valve at a second lost motion connection, whereby said check valve is isolated from any guiding influence of the stem or the actuator member during lost motion movement at the second lost motion connection, said end means effective to lift the check valve from said second valve seat after said lost motion movement at said second lost motion connection.

Claim 3

In a bidirectional high pressure balanced valve, a valve body having a cylindrical valve control chamber; first and second flow ports communicating with the chamber at axially spaced locations therealong; a first annular valve seat on the body between the control chamber and said first flow ports; a cylindrical valve closure disc disposed in the chamber, a first annular seating surface on the lower portion of the closure disc sealingly engageable the first valve seat, said closure disc being axially movable in said control chamber between an open position wherein said seating surface is spaced from the first valve seat to permit fluid flow between the ports and a closed position wherein said seating surface sealingly engages said first annular valve seat to prevent flow past the seat between the ports; an axial passage formed through the closure disc; a cylindrical counterbore coaxially formed in the upper portion of the closure disc; a hollow shaft rigidly coaxially connected at a lower end to the closure disc, a second counterbore formed at the lower end of the shaft adjacent the first counterbore, said second counterbore having a larger diameter than the first counterbore, the base of the second counterbore and the top surface of the closure disc defining an annular chamber with axially spaced surfaces; a piston rigidly connected to the shaft in axially spaced relationship to said closUre disc, said piston slidably engaging the surfaces of said control chamber and guiding said closure disc and said collar for axial movement in said control chamber between said open position and said closed position; a frusto-conical second valve seat on the closure disc formed coaxially with axial passage and the first counterbore; a cylindrical check valve having a central opening and an outer cylindrical surface slidably guidably supported by the inner cylindrical surface of the first counterbore, said check valve having a downwardly projecting conical end engageable with the seat and adapted to open or close said fluid passage through said closure member in response to pressure changes in said inlet port and said control chamber; a valve stem; means for moving said valve stem in opposite directions; a collar slidably supported in the second counterbore and connected to said valve stem for lost motion movement between the axially space surfaces of said base and said top surface; axial fluid passages on the check valve and the collar for permitting fluid communication on said first port and the control chamber; a lower end on the stem projecting freely through said central opening in the check valve at a second lost motion connection, whereby said check valve is isolated from the guiding influences of the stem during lost motion movement at the second lost motion connection, said stem having an enlarged terminal end engaging the lower surface of the check valve adjacent the central opening so as to be effective to lift the check valve from said second valve seat after said last mentioned lost motion movement.

Claim 4

In a bidirectional high pressure balanced valve, a valve body having a cylindrical valve control chamber; first and second flow ports communicating with the chamber at axially spaced locations therealong; a first annular valve seat on the body between the control chamber and said first flow ports; a cylindrical valve closure disc disposed in the chamber, a first annular seating surface on the lower portion of the closure disc sealingly engageable the first valve seat, said closure disc being axially movable in said control chamber between an open position wherein said seating surface is spaced from the first valve seat to permit fluid flow between the ports and a closed position wherein said seating surface sealingly engages said first annular valve seat to prevent flow past the seat between the ports; an axial passage formed through the closure disc; a cylindrical counterbore coaxially formed in the upper portion of the closure disc; a hollow shaft rigidly coaxially connected at a lower end to the closure disc, a second counterbore formed at the lower end of the shaft adjacent the first counterbore, said second counterbore having a larger diameter than the first counterbore, the base of the second counterbore and the top surface of the closure disc defining an annular chamber with axially spaced surfaces; a piston rigidly connected to the shaft in axially spaced relationship to said closUre disc, said piston slidably engaging the surfaces of said control chamber and guiding said closure disc and said collar for axial movement in said control chamber between said open position and said closed position; a frusto-conical second valve seat on the closure disc formed coaxially with axial passage and the first counterbore; a cylindrical check valve having a central opening and an outer cylindrical surface slidably guidably supported by the inner cylindrical surface of the first counterbore, said check valve having a downwardly projecting conical end engageable with the seat and adapted to open or close said fluid passage through said closure member in response to pressure changes in said inlet port and said control chamber; a valve stem; means for moving said valve stem in opposite directions; a collar slidably supported in the second counterbore and connected to said valve stem for lost motion movement between the axially space surfaces of said base and said top surface; axial fluid passages on the check valve and the collar for permitting fluid communication on said first port and the control chamber; a lower end on the stem projecting freely through said central opening in the check valve at a second lost motion connection, whereby said check valve is isolated from the guiding influences of the stem during lost motion movement at the second lost motion connection, said stem having an enlarged terminal end engaging the lower surface of the check valve adjacent the central opening so as to be effective to lift the check valve from said second valve seat after said last mentioned lost motion movement.