The AX107X piston safety pressure relief/holding valve is primarily used in fire fighting or other water supply systems to prevent system overpressure or maintain pressure in fire water supply systems. When the fire pump is turned off, the impact of water hammer can also be reduced. It is also used as a water hammer eliminator for large water supply systems. And the inlet of the valve control system is equipped with a self-cleaning filter, which uses the fluid characteristics so that the suspended particles with a larger specific gravity and larger diameter will not enter the control system. Ensure unimpeded system circulation and allow valves to operate safely and reliably. The system has smooth action, high strength and long service life, and is suitable for pipelines below 600 caliber.