X500X-Holding Pressure/Relief Pressure Valve

principle:
The inlet side of the main valve is connected to the pilot valve via a control pipe.when the pressure on the said is over the one set with the pilot valve,the pilot valve is oppened to release in the upper cavity of the diaphragm and the main valve is released to the set one ,the pilot valve is closed,so does the main valve.

purpose:
This valve is used for the high building fore-fighting system.when the pressure in the water supply pipeline is ove the set one for the pressure releasing valve,the said valve is opened to prevent the pipeline and equipment against damage due to an excessive pressure;then,when pressure lower to the set value.automatically closed.

characteristic
The body uses full passage streamline design,of a small fluid resistance and a heav flow,this valve can be used as either a pressure releasing or holding valve,when used as the former,it acn release the pressure surpassing the safe value set with the pilot valve to prevent system against danger due to an ex-cessively high water supply pressure of the main valve over someset value,this is beause water supply to the downstream can not be done,unless the upstream is higher than be set value,in  order to make sure of he upstream water supply pressure of the main valve.