AX742X safety relief/holding valve
structural characteristics
This product consists of a main valve, a needle type regulating valve, a pilot valve, a ball valve, and a connecting pipe system. The main valve body adopts a full channel, DC, streamlined design, and adopts two types of structures: diaphragm or piston. This product uses the set pressure regulating pilot valve spring pressure and the adjustable needle valve opening to set the outlet pressure, and stabilizes the outlet pressure through feedback from the connecting system and control room.
This product utilizes needle type regulating valves and pilot valves for self controlled water pressure, without the need for additional devices or energy sources. It is easy to maintain, minimally affected by inlet pressure and flow rate, with high accuracy in pressure control and reliable pressure reduction and stabilization.

working principle
When water is supplied from the inlet end of the pipeline, it flows through the needle valve into the main valve control room, and the outlet pressure acts on the pilot valve through the conduit. When the outlet pressure is higher than the set value of the pilot valve, the pilot valve closes and the control room stops draining. At this time, the pressure in the main valve control room increases and the main valve closes, and the outlet pressure no longer increases.
When the outlet pressure drops to the set pressure of the pilot valve, the pilot valve opens and the control room drains downstream. Due to the drainage volume of the pilot valve being greater than the inlet volume of the needle valve, the pressure in the control room of the main valve decreases, and the inlet pressure causes the main valve to open. In a stable state, the inlet and outlet pressure of the control room remain the same, with the same opening and drainage.
Adjust the guide valve spring to set the outlet pressure.

Job characteristics
1. Pressure control is stable and reliable. The pilot valve and main valve work continuously, and the downstream pressure changes continuously and steadily, with little influence from the inlet pressure.
2. Easy to operate. After setting the working pressure, the main valve automatically adjusts when the upstream pressure or flow rate changes, stabilizing the downstream pressure.
3. The valve body adopts a full channel, DC, streamlined design. Low hydraulic loss and good energy-saving effect.

Function and purpose
This valve is generally installed upstream of the water supply pipeline system to achieve pressure reduction and stabilization functions for downstream pipelines or devices.
This series of valve products is widely used for water pressure control in high-rise buildings, living areas, or other water supply network systems.
Main technical parameters

Main component materials Part Name Part material Valve body and valve cover WCB Valve seat disc Copper alloy/2Cr13 Sealing ring O-ring Nitrile rubber valve stem 2Cr13 spring 50CrVA Cylinder liner piston (piston type) 2Cr13 Diaphragm (Diaphragm type) Nitrile rubber sandwiched fabric Regulating valve ball valve copper alloy filter stainless steel
Parts List: 1. Pressure gauge 2, filter 3, control valve 4, flow regulating valve 5, main valve

connection size