| 摘要 |
A pilot controlled diaphragm shut-off valve (13) includes a cushion body (22) disposed in a pilot pressure chamber (20). The cushion body (22)operates to gradually allow the build up of pressure in the pilot pressure chamber (20) as water enters through a pilot orifice (21a) into the pilot pressure chamber (20). Such gradual pressure build up in the pilot pressure chamber (20) allows a gradual closing velocity of the shut-off diaphragm valve (13) and thereby eliminates the water hammer phenomena. An actuating diaphragm (32) is provided for opening and closing a pilot valve (24). Alternatively, a float (43) may be employed for opening and closing the pilot valve (24). Either the actuating diaphragm (32) or the float (43) is linked to a stem (23) and lever (26) mechanism, or alternatively to a magnetic linkage (40, 41, 42a).
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