Patent ID: 7762276

Claim:
A check valve comprising: a unitary hollow main body having an inner surface, a first end wall at a first end of the unitary hollow main body, the first end wall forming a first aperture and having a curved outer surface and a concave seating surface, and a second end wall at a second end of the unitary hollow main body, the second end wall forming a concave seat and a second aperture, the first end wall separated from the second end wall by a sidewall having an annular outer surface and an annular inner surface, the curved outer surface of the first end wall extending from the first aperture to the annular outer surface, wherein a wall thickness of the first end wall of the main body is defined by an average distance between the curved outer surface and the concave seating surface of the first end wall and is greater than a wall thickness of a rest of the main body; a poppet valve disposed in the main body, the poppet valve having an outer surface and an inner surface, the outer surface including a convex seating surface adapted to abut the concave seating surface of the main body, the outer surface including an annular ridge defining a corresponding raised portion on the inner surface of the poppet valve, the inner surface having a concave seat disposed adjacent the raised portion defined by the annular ridge, wherein the poppet valve includes at least one radially outwardly extending tab formed thereon for abutting the inner surface of the main body, the at least one radially outwardly extending tab connected to the poppet valve at a first terminal end of the tab and bending laterally outwardly substantially at a second terminal end of the tab, the terminal end having an end surface substantially parallel with the annular inner surface of the sidewall of the main body; and a coil spring disposed in the main body adapted to urge the poppet valve towards the seating surface of the main body, wherein the coil spring has a first end and a second end, the first end abutting the concave seat of the second end wall, and the second end abutting the concave seat of the poppet valve, the first end of the coil spring having a width greater than widths of the second end of the coil spring, the first aperture of the first end wall, and the second aperture of the second end wall, the second end of the coil spring surrounding and cooperating with the raised portion on the inner surface of the poppet valve to align the poppet valve inside the main body.