Working principle of safety valve air release valve

The safety valve is a safety device to prevent pressure equipment and containers or easy to cause pressure rise or the internal pressure of the container exceeds the limit and burst. The safety valve is a widely used safety device for pressure systems such as pressure vessels, boilers and pressure pipes to ensure the safe operation of the pressure system.

When the pressure of the container exceeds the design requirements, the safety valve opens automatically, and the excessive pressure in the exhaust gas reducer is prevented to prevent damage to the container or pipeline. When the pressure in the container drops to the normal operating pressure, it is automatically closed to avoid exhausting all the gas due to the overpressure of the container, resulting in waste and production interruption. The safety valve is mainly composed of three parts: a valve seat, a valve disc (plug) and a loading mechanism. 

Some valve seats are integrated with the valve body, and some are assembled with the valve body, which communicates with the equipment. The valve plug is often connected with a valve stem, which is fastened on the valve seat. Above the valve flap is the loading mechanism, the size of the load can be adjusted. When the pressure in the equipment is within a certain working pressure range, the force of the internal medium acting on the valve flap is less than the force applied by the loading mechanism on the valve. The difference between the two constitutes the sealing force between the valve flap and the valve seat. 

The valve disc is pressed tightly against the valve seat, and the medium of the device cannot be discharged. When the pressure in the device exceeds the specified working pressure and reaches the opening pressure of the safety valve, the force of the internal medium acting on the flap is greater than the force exerted on it by the loading mechanism, so the flap leaves the seat and the safety valve opens. The medium inside is discharged through the valve seat. If the displacement of the safety valve is greater than the safe discharge of the equipment, the pressure in the equipment gradually decreases, and after a short time of exhaust, the pressure drops back to the normal working pressure. At this time, the force that the internal pressure acts on the valve flap is less than the force exerted on it by the loading mechanism. 

The valve flap presses the valve seat again, the medium stops discharging, and the device maintains the normal working pressure and continues to operate. Therefore, the safety valve is closed or opened by itself through the increase and decrease of the medium force on the valve flap and the force of the loading mechanism to prevent the overpressure of the device.

Sunthai's hygienice stainless steel pressure over flow valves are widely used in fermentation tank,beer tank,food processing,dairy industries.