Y43h Pilot Piston Steam Reducing Valve

• Media: Steam Oil Water
• Certification: CCC, RoHS, ISO, CE
• Temperature: High Temperature
• Connection: Flange
• Valve Seat: Single-Seat
• Structure: Lever
• Model NO.: Y43H
• Material: Stainless Steel Carbon Steel Brass
• Transport Package: Wooden Box
• Specification: DN15-DN800
• Trademark: XC
• Origin: China
• HS Code: 8481804090
• Production Capacity: 9999

Product Description

Y43H pilot piston steam reducing valve is a kind of pressure reducing valve widely used in steam pipeline system, which uses piston as the element to drive the spool action. It is more durable and has long service life than the film pressure reducing valve which is used as the driving element.
The pilot type structure makes it more accurate to adjust, twice as accurate as the direct acting type pressure reducing valve. The outlet pressure deviation is not more than 5% of the outlet pressure.
Pilot operated pressure reducing valve is mainly composed of pilot valve and main valve. The pilot valve acts as the leader of pressure regulation, and the main valve is the executor of the pilot valve. The two work closely together to complete the decompression process. A problem with either can cause the process to fail.
The pilot valve is mainly composed of pilot valve body, pilot valve core, pilot valve seat, pilot valve spring, adjustment spring, adjustment screw, diaphragm and other parts.
The diaphragm of the pilot valve can sense the pressure after the valve, and change the opening height of the pilot valve core according to the change of the pressure after the valve, and control the flow of the imported medium to the top of the piston. The adjusting spring is used to set the adjusting pressure range, and the adjusting screw can change the outlet pressure.
The main valve is composed of body, piston, piston ring, cylinder liner, main spool, main seat, main valve spring, bottom cover and other parts. The medium flowing out of the pilot valve reaches the top of the piston, and pushes the piston down under the pressure of the medium, driving the main spool to open.

Working principle: Rotate the adjusting screw clockwise, compress the adjusting spring, elastic deformation of the spring, push the diaphragm to act first, while the pilot valve core moves down, the pilot valve core opens, (the medium through the main valve body in the diversion hole, to the pilot valve core position waiting for a long time). The medium through the guide valve core, the guide valve seat sealing surface, through the guide valve inside the diversion hole to reach the main valve piston above. Push the piston down to drive the main valve spool open, the medium flows between the main valve spool and the main valve seat, and reaches the valve outlet, and the pressure after the valve begins to rise.
Continue to turn the adjusting screw clockwise, and the pressure behind the valve continues to rise. When you reach the set pressure value, stop turning the regulating screw and lock it. The pressure after the valve passes through the feedback guide hole in the main valve body to the bottom of the pilot valve diaphragm, and the pressure acting on the bottom of the diaphragm and the force acting on the regulator spring on the top of the diaphragm reach balance. The pilot valve spool maintains a certain opening, and the main valve spool also maintains a certain opening. The inlet and outlet pressure is maintained in a balanced state.
When the outlet pressure rises, the pressure under the pilot valve diaphragm rises, the pressure under the diaphragm is greater than the regulating spring pressure, the diaphragm moves upward, the pilot valve spool tends to close under the action of the pilot valve spring, the medium pressure above the main valve piston becomes smaller, the main valve spool tends to close under the action of the main valve spring, the main valve spool and the main valve seat throttle area becomes smaller, so that the pressure after the valve decreases. Until the balance is re-reached.
When the outlet pressure drops, the pressure below the pilot valve diaphragm drops, the pressure below the diaphragm is less than the regulating spring force, the diaphragm moves down, driving the pilot valve spool downward action, the pilot valve spool tends to open, the medium pressure above the main valve piston increases, the piston moves down, driving the main valve spool opening increase, the pressure after the valve rises, the pressure is restored to balance.
Y43H pilot piston type steam pressure reducing valve, because of high temperature resistance, more used in steam systems. Because the spool seal is a metal hard seal, it can only reduce the dynamic pressure, can not reduce the static pressure (static pressure refers to the steam in the pipeline after the valve is not consumed, closed in the pipeline or container), the medium will leak from the main spool and the main seat sealing surface to the outlet end. At this time, the pressure after the valve will slowly rise, exceeding the set value, resulting in the opening of the safety valve behind. Close the stop valve at the inlet of the reducing valve when not in use to avoid accidents.