Main structure size of FX-AX742X safety relief/holding valve        unit：mm

     The safety relief and pressure holding valve is composed of a main valve, a needle-type regulating valve, a pilot valve, a Ball Valve and a pipe connection system. The main valve body adopts a full-channel, direct-flow, streamlined design, and adopts two types of structures: diaphragm or piston. This product sets the outlet pressure by setting the spring pressure of the pressure regulating pilot valve and adjusting the opening of the needle valve, and stabilizes the outlet pressure through the feedback effect of the takeover system and the control room. AX742X safety relief/holding valve uses needle-type regulating valve and pilot valve to control water pressure independently. It does not require additional devices and energy sources. It is easy to maintain and is not affected by the inlet pressure and flow rate. The pressure control accuracy is high and the pressure is reduced. Reliable voltage regulation.
When the pipeline feeds water from the water inlet end, the water flows through the needle valve and enters the main valve control room. The outlet pressure acts on the pilot valve through the conduit. When the outlet pressure is higher than the pilot valve setting value, the pilot valve closes and the control room stops draining. At this time, the pressure in the main valve control chamber increases and the main valve is closed, and the outlet pressure does not increase anymore.

      When the outlet pressure of the safety relief pressure holding valve drops to the set pressure of the pilot valve, the pilot valve opens and the control room drains downstream. Since the water discharge of the pilot valve is greater than the water intake of the needle valve, the pressure in the control chamber of the main valve drops, and the inlet pressure causes the main valve to open. In a stable state, the control room has the same inlet and outlet water, the opening degree remains the same, and the outlet pressure remains the same. The outlet pressure can be set by adjusting the spring of the pilot valve.

      1. The pressure control is stable and reliable. The pilot valve and the main valve work continuously, and the downstream pressure changes continuously and smoothly, and is not affected by the inlet pressure.
2. Easy to operate. After the working pressure is adjusted, the main valve automatically adjusts when the upstream pressure or flow changes to stabilize the downstream pressure. 3. The valve body adopts a full-channel, direct-flow and streamlined design. The hydraulic loss is small and the energy saving effect is good.

     The AX742X safety relief/holding valve is generally installed in the upstream of the water supply pipe network system to realize the pressure reducing and stabilizing function of the downstream pipe network or device. FX-AX742X safety relief/holding valve is widely used for water pressure control in high-rise buildings, living areas or other water supply pipe network systems.