The valves instantly opens when the pressure in the pipeline exceeds the preset safe level, thus relieving excessive pressure from the pipeline. When the pressure returns to normal, the valves closes slowly, at an adjustable speed.The valves also can be used to sustain upstream pressure to a preset pressure value.

The 500X pressure release/maintenance valves is mainly used in fire fighting or other water supply systems to prevent the occurrence of overpressureor maintain the pressure of a fire fighting water supplysystem. After the fire pump is shut down, the valves can also serve to reduce the impact caused by water hammer. It can also be used as the water hammer eliminating device in large water supply systems.The valves utilizes a self-cleaning screen installed at the inlet of the valves control system, so suspended particles of relatively big specific gravities and diameters can not enter the control system.This guarantees the smooth and unobstructed circulation of the system, thereby ensuring the safe and reliable operation of the valves. With the help of the valves, the system, suitable for 600 caliber or below pipes, is able to operate smoothly, high in strength and offer a long service life.