For safety and equipment protection

the knurled brass design often allows for reliable hand-tightening to establish a proper electrical ground

Contractor-Ready Design: Equipped with two wiring terminals and two hose ports to streamline replacement in mobile home furnaces and residential downflow units

this unit is a verified cross-reference for the Wilbur Curtis WC-1865 "SPB" series black plastic faucet

but you must never go lower

Cleveland Controls AFS-A-173 Pressure Switch For safety and equipment protectionThe Cleveland Controls AFS A 173 is a high performance adjustable pressure switch designed for critical airflow proving in package burners, furnaces, and fuel burning equipment. This SPDT air pressure switch offers a versatile field adjustable set point range from 0. 05" 0. 02" w. c. to 12" w. c., allowing for precise calibration in positive, negative, or differential pressure applications. Built with a plated housing and a durable silicone diaphragm,