Tubular refrigerant check valve with snap-together internal valve cage structure

A check valve connectable in a refrigerant line is economically fabricated from only four parts-(1) a copper tubing body connectable in the refrigerant line, (2) a nonmetallic shutoff ball, (3) an annular valve seat member having a diametrically opposite pair of leg portions axially projecting from one end thereof, and (4) an annular stop member also having a diametrically opposite pair of leg portions axially projecting from one end thereof, and further having a diametrically opposite pair of axially extending outer side surface grooves formed therein. The seat and stop members are locked together to form a cage structure by axially press-fitting the valve seat member outer leg ends into the stop member grooves in a manner such that the stop member legs underlie and support the seat member legs, with outer ends of the stop member legs facing a conical seating surface of the seat member in an axially spaced relationship therewith. The shutoff ball is captively retained laterally between the seat member legs for axial movement within the cage structure between an open position in which the ball seals against the seating surface, and an open position in which the ball is axially moved away from the seating surface and is stopped by the outer ends of the stop member legs. The cage is coaxially and captively retained in a longitudinally central portion of the copper tubing body between two elongated, spun-down, reduced diameter end portions thereof that may be soldered into a refrigerant line.