General Pump Compact Thermal Relief Valve 3/8" MPT 145°F – OEM Replacement Part

Part Number: 100557
Category: Pressure Washer Components → Thermal Relief Valves → General Pump Parts
Type: General Pump Compact Thermal Relief Valve

The General Pump Compact Thermal Relief Valve (Part #100557) is a genuine OEM safety component designed to protect pressure washer and softwash pumps from overheating during bypass and idle operation. Engineered to automatically activate at approximately 145°F, this thermal relief valve releases overheated water and allows cooler incoming water to enter the system, helping prevent costly damage to seals, packings, valves, and other critical pump components.

Key Features & Benefits

• Genuine General Pump OEM Replacement Part
• Protects pumps from overheating during bypass operation
• Automatically activates at approximately 145°F
• Automatic reset functionality after cooling
• Durable brass body with stainless steel internal components
• Compact design for easy installation in tight spaces
• Helps prevent premature seal and packing failure
• Reduces pump wear caused by excessive heat buildup
• Suitable for softwash and pressure washer systems
• Improves pump reliability and service life

Technical Specifications

Manufacturer: General Pump

Part Number: 100557

Product Type: Thermal Relief Valve

Connection Size: 3/8" MPT

Connection Type: Male Pipe Thread (MPT)

Activation Temperature: 145°F (±5°F)

Maximum Pressure: Up to 4000 PSI (system dependent)

Body Material: Brass

Internal Components: Stainless Steel

Reset Type: Automatic Reset

Application: Pump Overheat Protection

OEM Replacement: Yes

Typical Applications

• Pressure washer systems
• Softwash systems
• Pump bypass loops
• High-flow pump installations
• Commercial pressure washing equipment
• Industrial cleaning systems
• Mobile wash rigs
• Pump protection and safety systems

Performance Advantages

• Automatically protects pumps from heat-related damage
• Prevents overheating during extended bypass operation
• Extends seal, packing, and pump component life
• Helps reduce maintenance and repair costs
• Automatic reset operation requires no manual intervention
• Compact design simplifies installation
• Durable brass and stainless steel construction ensures long service life
• Improves overall system reliability and safety
• Ideal for commercial and professional cleaning equipment

Installation Locations

The General Pump 100557 Thermal Relief Valve can be installed in:

• Pump manifold ports
• Bypass plumbing loops
• Inlet water supply lines
• Softwash system plumbing
• Pressure washer pump protection circuits

Always follow equipment manufacturer recommendations for installation location.

Maintenance Recommendations

• Inspect the thermal relief valve periodically for leaks or damage.
• Verify proper activation and reset operation during maintenance intervals.
• Replace valves showing signs of wear or improper function.
• Ensure adequate water supply to the pump system.
• Follow General Pump installation guidelines.
• Use only genuine OEM replacement components to maintain proper performance