QF508 Pressure Regulating Valve Full Introduction
1. Basic Overview
Full Name: QF508 Pneumatic Pressure Regulating Valve (also known as pneumatic automatic pressure control valve, air compressor on-off control valve)
Mainstream Brand: WHZHPC / Weihai Zhonghao Pneumatic & Hydraulic
Product Positioning: Direct-acting spring feedback pneumatic on-off pressure regulating valve, specially matched for industrial air compressors. It automatically controls compressor start/stop and pressure stabilization through force balance between air pressure and spring force. It is a standard pneumatic component for petroleum workover rigs and mining drilling rigs.
Applicable Medium: Dry compressed air (oil-free clean air compressor air source preferred)
2. Core Technical Parameters
Item Specification
Nominal Bore 6mm
Standard Pressure Range 0.5MPa (lower limit for shutdown) ~ 0.8MPa (upper limit for startup), differential pressure: 0.3MPa
Max Working Pressure 1.5MPa
Allowable Leakage Rate ≤500ml/min
Ambient Temperature -25℃ ~ +60℃ (customizable for ultra-low temperature -40℃)
Port Thread Inlet: G1", Control Port: ZG1/4"
Overall Length 165mm, Valve Body Outer Diameter: 52mm
Net Weight Approx. 1.9kg
Body Material Forged brass body, alloy steel spool, heat-treated 65Mn spring, oil-resistant rubber seals
Warranty 3 months standard factory warranty
3. Internal Structure
Consists of 8 core assembled parts: brass valve body, valve spool, adjusting sleeve, push rod, main pressure regulating spring, lock nut, adjusting handwheel and auxiliary exhaust port. Adopts integrated compact structure; the top handwheel can be manually rotated on-site to fine-tune the pressure range.
4. Working Principle
1. When air pressure ＜ 0.5MPa (below lower limit): Air source thrust ＜ spring preload force, the spool closes the main air passage and opens the exhaust passage; the air tire inflates and the air compressor starts charging air.
2. When air pressure rises to 0.8MPa (reaches upper limit): Air source thrust ＞ spring preload force, the spool is pushed upward to open the main air passage and close the exhaust passage; the air tire depressurizes and the air compressor shuts down automatically.
3. When system leakage causes pressure to drop back to 0.5MPa, startup is triggered again. The system circulates to maintain stable pressure within 0.5~0.8MPa fully automatically without manual operation.
5. Product Features
1. Fully mechanical self-operated design, no electric control or pilot air source required, anti-vibration and dustproof for harsh field working conditions.
2. Brass valve body with rust and corrosion resistance, wear-resistant seals, low internal leakage after frequent long-term on-off cycles.
3. Top handwheel for stepless fine adjustment of spring preload to slightly modify the start-stop pressure range.
4. Equipped with redundant exhaust port for fast pressure relief, preventing air compressor overload and overpressure damage.
5. Reinforced structure adapted to high-vibration equipment for drilling rigs and vehicle-mounted mobile machinery.
6. Main Application Scenarios
1. Petroleum Equipment: Onshore workover rigs, petroleum drilling rigs, pneumatic control systems of vehicle-mounted drilling air compressors (primary application)
2. Construction Machinery: Geological exploration drilling rigs, mining rock drilling pneumatic equipment
3. Special Equipment: Marine deck air compressors, heavy mining machinery, vehicle-mounted mobile air compressors
Function: Regulate the overall air supply system pressure, realize reasonable switching between no-load and loaded operation of air compressors, and avoid pipeline rupture and equipment overload failure.
7. Installation & Commissioning Instructions
1. Installation Mode: Vertical upright mounting; the inlet port connects to the main pipeline of the air compressor air receiver tank.
2. Piping Layout: Port P (G1") connects to high-pressure air source; ZG1/4" port connects to air tire/actuator.
3. Pressure Adjustment: Rotate the top handwheel clockwise to compress the spring and raise the overall pressure range; rotate counterclockwise to lower the pressure range.
4. Pre-installation Recommendation: Install a small oil-water separator upstream of the inlet to prevent impurities and oil sludge from jamming the spool.
