摘要 |
The device comprises a body having an inlet and outlet port 11, 12 with a valve member 17 controlling the flow therebetween and a reservoir 29 communicating with the inlet port via bleed means (28 or 162) adjustable manually or automatically by flow pressure, a wall of the reservoir being formed by a flexible member 14 and means operably interconnecting the flexible member and the valve member. When sufficient pressure is established in the reservoir by the fluid bled thereinto the valve member 17 closes, the period of time taken before the valve 17 closes being determined by adjustment of the bleed means. An air vent 62 is closed automatically by the rising level in reservoir 29 prior to pressure being established therein. A normally closed dump valve 43 opens automatically when main inlet pressure is relieved. Several devices may be connected in series to automatically operate in sequence. <IMAGE> |