摘要 |
A control device associated with a pneumatically-driven demand pump comprising a valve system which shuts off the gas which drives the pneumatic pump in response to a pressure-sensitive diaphragm which detects variations in pressure in the fluid output from the pump. The pressure-sensitive diaphragm serves the dual function of suppressing surges of liquid flow from the pump and stopping the pump when the liquid pressure drops below a predetermined minimum by closing a valve to shut off the gas. |