| 摘要 |
<p>A valve (1) has an aluminium body (2) having four inlets (3) for fluid to be controlled at one, planar end (4) of the body. Centrally of the inlets (3) is a control fluid inlet (6). A shuttle chamber (8) extends away from the inlet (6), with drillings (9), extending from the inlets (3), arranged radially of the shuttle chamber. The latter has an opening (10) at an outlet end (11) of the body, where an outlet end plate (12) is bolted on, to which a spray nozzle (14) is fitted. A shuttle (21) is arranged in the chamber (8) for control of fluid flow from the nozzle. Also an aluminium, shuttle guide (22) is provided in the chamber (8). The guide is sealed to the chamber by a sealing ring (26) in a groove (27) and retained by a spring clip (28) in a groove (29) in the body. The shuttle (21), of nylon material, has a piston (30) and a stem (31). Each has a respective groove (32, 33) for lip seals (34, 35) the first seals the piston to the smaller diameter portion of the chamber and the second seals the stem in shuttle guide (22). Aspring (37) biases the shuttle towards the inlet end (4) of the body, minimising the actuation space (38) in absence of control pressure therein. The distal end (41) of the shuttle stem (31) has a recess (42) for a closure member in the form of a synthetic elastomer block (43). This co-operates with the inner end (44) of the nozzle (14), so as to close the nozzle when control pressure is applied behind the piston via the control fluid inlet (6) into the actuation space (24) to move the piston forward and the block into abutment with the nozzle. Release of the control pressure allows the spring (37) to move the piston back, whereupon the pressure of the fluid being controlled acts on the block, adding to the spring force, and the valve snaps open.</p> |
