According to different structures and working principles, pressure reducing valves can be divided into several main types:
1. Direct acting pressure reducing valve
Valve structural characteristics:
-Simple and compact structure
-The spring directly acts on the diaphragm
-Contact outlet pressure below the diaphragm
Working principle :
The spring force directly opposes the outlet pressure and controls the valve disc position through mechanical linkage. The pressure setting is achieved by adjusting the pre tension force of the spring.
Advantages and disadvantages :
-Advantages: Fast response, low cost, simple maintenance
-Disadvantages: Low accuracy (± 10-15%), not suitable for high flow or high pressure drop situations
Typical application :
Household gas pressure reducing valve, small air compressor outlet, low precision industrial application
2. Pilot operated pressure reducing valve
Valve structural characteristics:
-Composed of a main valve and a pilot valve
-Adopting a two-stage decompression structure
-The pilot valve controls the action of the main valve
Working Principle:
The pilot valve senses the outlet pressure and controls the pressure chamber above the main valve piston. When the outlet pressure changes, the pilot valve adjusts the pressure in the pressure chamber, thereby controlling the opening of the main valve.
Advantages and disadvantages :
-Advantages: High control accuracy (± 1-3%), suitable for large flow rates and high pressure differentials
-Disadvantages: Complex structure, high cost, high requirement for medium cleanliness
Typical application :
Industrial steam systems, large compressed air systems, and precision pressure control applications
3. Piston type and diaphragm type pressure reducing valves
Piston style features :
-Using metal pistons as sensing elements
-Good resistance to high pressure and high temperature
-High friction and low sensitivity
Diaphragm Features :
-Using elastic membrane as sensing element
-High sensitivity and fast response
-Not resistant to high pressure and high temperature, with a relatively short lifespan
4. Special type pressure reducing valve
-Differential pressure reducing valve: maintains a fixed pressure difference between two pressure points
-Double stage pressure reducing valve: Connecting two pressure reducing valves in series to achieve a larger pressure reduction ratio
- Electric pressure reducing valve : using electric actuators for remote control and precise adjustment
