Safety valve

A safety valve comprising:

• a body having a fluid inlet and a fluid outlet and an internal passageway between the inlet and outlet, the passageway being defined in part by a reduced internal diameter seating port providing an internal radial ledge;
• a cylindrical seat member having an axial passageway therethrough and having an upper and a lower planar face, the lower face engaging said body internal radial ledge, the upper face having a circumferential groove therein defined by an outer cylindrical surface, a radial bottom surface parallel said lower planar face, and an inner frusto-conical surface tapering inwardly in the upper direction whereby the width of the groove is wider at the top than at the bottom;
• a toroidal elastomeric seal received in said seat member being defined by an outer cylindrical surface, and a radial bottom surface of substantially the dimensions of said seat member groove, by an inner frusto-conical surface of height greater than said groove inner frusto-conical surface, and by an upper surface the outer diameter portion of which is substantially co-planar with said seat upper planar face, and the inner diameter portion which is of a height greater than said seat upper planar face thereby providing an integral upwardly extending reduced internal diameter lip portion;
• a cylindrical seat retainer member positioned within said valve body having a seat member engaging surface, an outer diameter portion of which is planar and which engages the outer diameter portion of said seat member upper planar face and said upper planar outer diameter surface of said seal and engages the outer diameter portion of said seal integral upwardly extending lip portion;
• means to secure said seat retainer within said valve body;
• a ball member positioned within said body and above said seat;
• and
• means to urge said ball downwardly into engagement with said seal whereby in the downward position said ball engages said seal integral upwardly extending lip portion.