Patent ID: 7726335

Claim:
A fuel system check valve apparatus, comprising: a valve body including a through passage; a poppet valve consisting essentially entirely of a polymeric material and having a valve stem and a valve head adjacent one end of said valve stem, the valve head having a truncated conical portion and a shoulder at the downstream end of the conical portion and integral with the valve head and the entire valve head including the conical portion and the valve stem being in one piece of the polymeric material which is highly resistant to degradation when in long term contact with hydrocarbon fuels, the valve stem being carried by the body and guided for generally axial movement of the valve stem and head relative to the body to open and closed positions of the valve; and a separate valve seat assembly adapted for cooperation with said valve head of said poppet valve, said valve seat assembly including: a separate valve seat body of polymeric material received with an interference fit at least partially within the through passage of the valve body and fixed relative to the valve body; and a separate valve seat seal with a through passage and received only in and carried by said valve seat body independently of the valve body, said valve seat seal being composed of an elastomeric material constructed for sealing against said conical portion of said valve head of said poppet valve; and the valve seat body having a through passage which downstream of the valve seat seal has a conical surface which merges into a first cylindrical surface which transitions by a curved surface to a second cylindrical surface having an inside diameter smaller than the inside diameter of the first cylindrical surface and the inner diameter of the valve seat seal is smaller than the inside diameter of the second cylindrical surface and when the valve is closed the shoulder of the valve head is axially disposed in the first cylindrical surface and adjacent the conical surface of the valve seat body, and the shoulder has a smaller diameter than the inside diameter of the first cylindrical surface of the valve seat body, and the valve head engages only the separate valve seat seal.