Dual seal fitting for enabling quick measurement of brake cylinder pressure

摘要

A dual seal coupling fitting enables quick measurement of pressure. The fitting includes primary and secondary valves and has one end shaped like a male portion of a quick coupler and another end screwable into a threaded bore defined in a pressure bearing housing. The fitting defines first and second cylindrical sections in communication with each other. The primary valve situates in the first section, the secondary valve in the second section. The primary valve includes a valve stem with a poppet head. A first mechanism compresses the poppet head against an outer valve seat to close the primary valve thereby preventing leakage of pressure. The secondary valve features a cylindrical seat piece and a retainer. The piece secures within the second section and defines through itself an inner bore. The piece at one end forms an inner valve seat and at an opposite end situates adjacent the first mechanism. The retainer has at one end a post approximate a terminal end of the valve stem within the inner bore. The retainer also has a check valve retained within an annular recess defined about a base of the post. A second mechanism compresses the check valve against the inner valve seat to close the secondary valve thereby further preventing leakage of pressure. Mating a female portion of a quick coupler to the male portion opens the primary and secondary valves and enables quick measurement of the pressure via a gage attached to the other end of the female portion.