How does high-purity diaphragm valve work?

High purity diaphragm valve bodies are often made of plastic, fiberglass, ceramic, or metal lined rubber materials. Simple structure, good sealing and anti-corrosion performance, and low fluid resistance. Used for media with low pressure, low temperature, strong corrosiveness, and suspended substances. So do you know how high-purity diaphragm valves work? 
 

When the steam turbine is working normally, the diaphragm valve and lubricating oil system's turbine oil enter the oil chamber on the piston inside the valve, overcoming the spring force to keep the diaphragm valve in the closed position. The high-purity diaphragm valve blocks the oil discharge channel of the EH emergency shut-off oil main pipe, allowing the EH system to start working. When the emergency governor is activated or manually tripped, it can cause the turbine oil pressure to decrease or disappear, thereby opening the spring to release the EH emergency governor oil and closing the main steam valve and regulating valve. 
 

Connecting the low-pressure turbine oil system and high-pressure fire-resistant oil system, its function is to use the emergency governor slide valve to release oil from the mechanical manual shutdown main pipe when the turbine speed rises and the emergency governor device sends a shutdown signal. When the oil pressure drops to a certain value, the diaphragm valve opens to release oil from the AST oil main pipe, thus sealing the high and medium pressure automatic seals and high and medium pressure regulating valve actuators through the EH oil system. Force the turbine to shut down to ensure the safety of the turbine unit. 
 

High purity diaphragm valve is a shut-off valve that uses a diaphragm as an opening and closing element to close the flow channel, cut off the fluid, and separate the inner cavity of the valve body and the inner cavity of the valve cover. Diaphragm is commonly made of elastic, corrosion-resistant, and impermeable materials such as rubber and plastic.