Patent ID: 6863088

Claim:
A replaceable orifice unit constructed of a tube member ( 1 ), wherein an orifice piece ( 2 ) is fixedly mounted inside said tube member ( 1 ); and, each of opposite end portions of said tube member ( 1 ) has a coupling construction; wherein said orifice piece ( 2 ) assumes two similar triangular shapes in longitudinal cross section, each of which triangular shapes has its vertex oppositely disposed from each other with respect to a longitudinal axis of said tube member ( 1 ) to define an orifice ( 2 a ) between said vertexes of said triangular shapes, through which orifice ( 2 a ) a fluid in a fluid circuit is adapted to pass; wherein an O-ring is interposed between an inner peripheral wall of said tube member ( 1 ) and an outer peripheral surface of said orifice piece ( 2 ) to prevent the fluid of said fluid circuit from passing through between said inner peripheral wall of said tube member ( 1 ) and said outer peripheral surface of said orifice piece ( 2 ).