This 1-1/4 inch model is a standard mechanical safety relief valve designed for high-flow emergency discharge

installing a 20-mesh Y-strainer upstream is standard trade practice to prevent scale and debris from scoring the hardened seat and disc

The RP4A series is designed as a Reduced Pressure Zone (RPZ) assembly

this two-way control valve utilizes an equal percentage flow characteristic to ensure stable thermal output through a wide range of actuator positions

Engineered for precise HVAC part compatibility

Williams 6B149 Shield 322027-701 This 1-1/4 inch model isFor your next service call involving a 22,000 or 30,000 BTU Williams direct vent wall furnace, ensuring the integrity of the combustion chamber shield is paramount for maintaining manufacturer specified airflow and thermal protection. The Williams 6B149 is a genuine OEM furnace replacement part engineered specifically to fit between the combustion chamber and the main cabinet faceplate. This component acts as a critical thermal barrier, preventing