When learning about all kinds of hydraulic valves, surely there is something you wonder, that's why safety valve and a valve known as the overflow drain valve with the same symbol in the system diagram?

In previous articles, we know what safety valve, to get answers to the questions above, let's find out what is the overflow valves and operational functions and nothing like other than safety valve light!

1, What is overflow valves?

Overflow valve (Deluge valve) is like a safety valve, a hydraulic device with pressure control function input. It is an automated valves commonly used in water systems, especially fire. When there is a fire, the first sensor will transmit signals to the valves will automatically receive the signal and gives full discharge of the nozzles is already open.
 
In terms of active principle, no different overflow valve safety valve, but structural changes. Instead of the closed state and open only when the pressure at the set pressure valve branching fitting norms as a safety valve, overflow valve always in a state of open, constantly pouring liquid on the container to make sure the pressure in input of the valves is constant.
Overflow valve device is required for hydraulic circuit controlled by the throttle, usually mounted parallel to the pump to ensure the output pressure of the pump is always constant.
2, Structure, function

Valves including valve body, the sole valve, wing valve, crank, filters, ...
 
When the system in sleep mode, the membrane cavity (the lower body), due to be connected to water sources should be filled with water. The water pressure will affect the cylinder, piston, crankshaft, valves and wings help seal locked. When fires occur, the nozzle opening. The water pressure in the membrane cavity decreased, reducing the pressure acting on the cylinder, piston and crank. The system opens the valves supplying water and providing water for fire extinguishing nozzles.
Valve structure:
 
There are two ways to send signals overflow valve:
- Mechanical methods: Through the movement of currents, making crank calls impact the fire alarm.
- Electrical method: Through the water pressure and flow activation pressure switch or flow switch, sending electrical signals as calling bell.

3. Set up

- Clean the pipe before installing the valve.
- Insert a vertical overflow drain valve at the water where the temperature is just right, not frozen. Usually 1m above ground, 1.2 m from the wall. The ground must be equipped with drainage systems.
- Alarms should be placed in an airy place.
Water sources should be connected to the diaphragm chamber is connected to the main pipe (before van door).

* Check the water
- Close the control valve on the discharge pipe valves and control valves in the system.
- Slowly open control valve on the water supply system.
- When the steady pressure switches, valve gate valves supplying water to spill. When pressure gauges and stable water supplies, water being leaked and dumbbells, the overflow drain valve gasket no matter what and valve function normally.