| 摘要 |
In a safety valve for opening when over pressure occurs in a pressure tank of a hot water heater and comprising a spring-biassed diaphragm 5 clamped in place by a spring casing 6 screwed onto a valve casing 1, a spindle 8 is fastened to a central portion 5a of the diaphragm and the spindle is movable against the force of a compressible buffer 16 by the aid of means 12, 14 in order to empty the pressure tank. The buffer 16 has a greater spring force than a compression spring 9 which normally biasses the valve closed. Preferably damper means (B Figs 2,3) are provided downstream of the valve for preventing knocking and comprise a chamber (32) with a lower chamber portion (V) for water and an upper portion (L) for air at a higher level than the inlet and the outlet of the chamber. <IMAGE> |
