Patent ID: 7311118

Claim:
A floating ball check valve, comprising in combination: a. a body having inner and outer axially adjacent portions, with each non-adjacent end thereof including a coupling member, said body including a through bore, with said body inner portion having first and second concentric cylindrical bores and an outlet port; b. a cap having inner and outer axially adjacent cap portions, with each non-adjacent end thereof including a coupling member, said cap including a through bore, with said cap inner portion having a plurality of concentric cylindrical bores, said cap outer portion having an inlet port and a concentric conical surface, said body inner portion being adapted to be inserted into a first one of said plurality of cylindrical bores of said cap inner portion and coupled with said cap inner portion; c. a generally cylindrical ball guide having a through bore and axially spaced internal bore portions, said ball guide being adapted to be slidably inserted into said first bore of said body inner portion, said ball guide also including a ball pocket portion for receiving and axially centering a sealing ball; d. a biasing spring adapted to be inserted into said body through bore and confined between said body inner portion second bore and an opposing internal bore portion of said ball guide, said spring serving to bias said sealing ball in the direction of said inlet port; e. a generally annular seat retainer located adjacent to said conical bore of said cap outer portion, with a radial outer annular portion of said seat retainer being biased against a radial outer shoulder portion of said conical bore portion by an end surface of said body inner portion; and f. a generally ring shaped seat, of non-resilient plastic material, substantially received within said conical surface of said cap outer portion and retained therein via a radial inner annular portion of said seat retainer, with the spherical surface of said sealing ball being urged into a sharp corner line contact sealing engagement with an adjoining seal surface of said seat, wherein said adjoining seal surface takes the form of a curved seal surface having sufficient seal surface contact with said sealing ball to prevent excessive yielding of said non-resilient plastic seat material at predetermined operating temperatures and back pressures.