摘要:
A dual valve apparatus enables quick measurement of pressure contained within a housing. The housing has a main body, a check valve housed in the main body and a cover whose removal renders the check valve accessible. The check valve is normally compressed against a check valve seat to provide a first seal that prevents leakage of the pressure. The dual valve apparatus includes a modified cover, a valve body and a valve stem. The modified cover defines first and second bores axially offset from and in communication with one another. The first bore is at least partially threaded. When the modified cover is secured to the main body, the second bore is aligned with the check valve. The valve body accommodates a valve bore from its protuberant end to its threaded end. The protuberant end is shaped to mate with a female portion of a quick connect coupling. The threaded end screws into the first bore of the modified cover. Movable within the bores, the valve stem at its head end is normally compressed against a valve seat formed within the protuberant end of the valve bore to provide a second seal that further prevents leakage of the pressure. Mating the female portion to the protuberant end of the dual valve apparatus causes the valve stem to move away from its seat. The valve stem in turn unseats the check valve thereby providing access to and enabling measurement of the 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.
摘要:
A release graduating proportioning valve for a rail car brake system having a brake pipe, a brake cylinder, and a load sensor valve which selectively connects the control volume to the brake cylinder. The release graduating proportioning valve has a proportioning piston movable between a first position at which a control volume is isolated from atmosphere to a second position at which the control volume is connected to atmosphere, to enable graduated release of brake cylinder pressure. A port to atmosphere is provided in the valve body, and the port is connected to, or isolated from, the control volume responsive to movement of the proportioning piston.