Patent ID: 8596301

Claim:
A valve assembly comprising: a housing including a first chamber, a second chamber, and a valve seat disposed between said first and second chambers; a valve head disposed in said housing and moveable relative to said housing between an open position spaced from said valve seat and a closed position engaging said valve seat; a valve stem coupled to said valve head and said housing for moving said valve head relative to said housing between said open and closed positions; said valve head defining a bore extending through said valve head from said first chamber to said second chamber when said valve head is in said closed position; and a check valve disposed in said bore and configured to move between a sealed position preventing flow through said bore when a pressure difference between said second chamber and said first chamber is below a set value and an unsealed position allowing flow through said bore when said pressure difference is greater than said set value for relieving said pressure difference; wherein said valve stem extends into said bore, said valve stem and said valve head defining a space between said valve stem and said valve head extending annularly around said valve stem from said second chamber toward said check valve to define a flow path in communication with said first and second chambers when said check valve is in said unsealed position for allowing flow through said bore between said valve stem and said valve head when said check valve is in said unsealed position; said valve stem and said valve head defining corresponding races; and intermediate members positioned in said corresponding races between said valve stem and said valve head to retain said valve stem in said bore of said valve head; at least one of said corresponding races defining a portion of said flow path.