While many Lennox-brand components cross over to Allied Air brands (Armstrong/Ducane)

allowing for flexible control signal integration including 2-10VDC or floating point

which maintains airflow and minimizes energy consumption

causing pressure switch errors or hazardous exhaust leaks into the conditioned space

Spence E-3/4 Valve Els PW 17895 While many Lennox-brand components crossThe Spence E 3 4 is a 3 4 inch pilot operated pressure regulator designed for high performance steam service. Built with a rugged cast iron body and a normally closed design, this E series main valve is a staple for HVAC steam heating systems and industrial process control. It functions as the primary diaphragm actuated valve when paired with a variety of Spence pilots, allowing for precise pressure reduction, temperature regulation, or back pressure