Main Pressure Control Valve with Unloader Function

Brief Overview

This main pressure control valve is a pressure-operated electric switch engineered for precise tank pressure regulation on electrically driven air compressors. The integrated unloader valve prevents the compressor from starting under load, while the manual ON/OFF button provides direct operator control. The four-port aluminum manifold design accommodates multiple connection points, making this an essential component for shop air systems requiring reliable pressure cycling and load management.

Key Features

• Dual-function design: Combines pressure switch and unloader valve in a single assembly
• Manual cutoff control: ON/OFF button for immediate compressor shutdown without depressurizing the system
• Four-port manifold: Aluminum block with ¼" female ports for flexible plumbing configurations
• Wide operating range: 45–175 PSI capability accommodates various compressor sizes and applications
• Factory-preset pressure band: 85–115 PSI with 30–45 PSI differential for efficient tank cycling
• Load-prevention feature: Unloader valve protects motor from starting under tank pressure
• Robust construction: Aluminum manifold block paired with plastic housing enclosure

Business Advantages for Resellers

This is a high-turnover replacement and upgrade item for service shops, compressed air system integrators, and industrial maintenance operations. The four-port configuration and integrated unloader function appeal to customers upgrading from single-function switches or troubleshooting pressure regulation issues. Bulk stocking of this assembly supports repeat business from compressor service and repair shops, as pressure switches wear out and require replacement over time. The straightforward installation and standard ¼" connections minimize customer support calls.

Technical Specifications

Specification	Value
Product Type	Pressure-Operated Electric Switch with Unloader Valve
Operating Pressure Range	45–175 PSI
Factory Preset Setting	85–115 PSI
Pressure Differential	30–45 PSI
Electrical Rating	120 VAC, 20A
Contact Arrangement	Normally Closed (NC)
Manifold Ports	4 × ¼" Female
Housing Material	Reinforced plastic with aluminum manifold block
Connection Type	Threaded female ports
Manual Control	Push-button ON/OFF switch

Real-World Application

Use this assembly for primary tank pressure control on single-phase electric compressors in small-to-medium shops. The unloader valve eliminates motor strain during standby, while the wide pressure band (45–175 PSI) suits compressors ranging from portable units to stationary workshop installations. The four-port manifold supports connections to tank, discharge line, pilot line, and auxiliary circuits—typical for shop air systems requiring secondary regulation or filtered outlet lines.

Value Summary

Stock this pressure switch assembly for immediate availability to customers maintaining or upgrading their compressor air systems. The integrated unloader function and four-port manifold reduce the need for additional valves and fittings, simplifying installation and reducing component count. Standard ¼" connections ensure broad compatibility across compressor brands and models.