First, 500X relief valve structure and use of features:

500X pressure relief / pressure holding valve consists of a main valve, pressure relief / pressure pilot valve needle, ball valve, microfilter and pressure gauge to form a hydraulic control takeover system. The use of hydraulic automatic operation, that can be used for pressure relief valve can also be used as holding pressure valve. For pressure relief valve used to maintain the water supply pressure below the set safety value; do holding pressure valve can maintain the main valve upstream of the water pressure above the set value, maintaining the water supply pressure upstream of the main valve. 
 500X pressure relief valve using hydraulic self-control, do not need other devices and energy, easy maintenance, a valve and more. This series of valve products are widely used in high-rise buildings, living areas and other water supply pipe network systems and urban water supply projects.
 

Second, 500X pressure relief valve works:

1, as the pressure relief valve: When the pressure relief valve / pressure regulator to adjust the state, the water through the needle valve, the main valve control room, ball valve A, pressure relief / holding pressure pilot valve, ball valve B to export, this time Main valve is open. When the inlet pressure exceeds the safety value set by the pressure relief / pressure holding pilot valve, the pressure relief pilot valve will open automatically and release part of the water through the valve C to relieve the pressure in the pipeline. The pressure relief valve closes automatically when the pressure returns to its safe value. For pressure relief valve, the ball valve normally open. 
 2, as holding pressure valve: When the pressure relief valve / pilot pressure regulator to adjust the state, as long as the main valve inlet pressure below the pilot valve set, pilot valve is closed. The main control room pressure, the main valve is closed. When the pressure on the upstream of the main valve exceeds the set pressure of the pilot valve, the pilot valve can only be opened. The water in the control room is discharged to the outlet via the ball valve. The main valve of the control room is opened and the water supply is started, that is, the upstream hydraulic pressure is maintained. For holding pressure valve, ball valve C is normally closed or replaced with silk plug.
 

Third, 500X pressure relief valve main technical parameters:

 Fourth, 500X pressure relief valve main parts and materials:

Fifth, 500X pressure relief valve connection size (PN 1.0-2.5MPa):