it limits the escape of gas to within ANSI standards

With a 1/2 PSI max inlet pressure and a factory-set 3-6" wc outlet pressure

The KMC Controls HFO-0015 is a professional-grade 4-inch static pick-up tube engineered for precise pressure monitoring in high-demand HVAC and industrial environments

replacing it with a fresh SLG0123 restores quiet operation

Heil Quaker ICP 1057251 Sequencer it limits the escape ofThe Heil Quaker ICP 1057251 Sequencer is a critical multi circuit timing relay designed for precise electric heat sequencer control in residential and light commercial air handlers. Engineered for 5kW and 7. 5kW heating elements, this sequencer manages the staging of resistive loads to prevent electrical demand surges that can trip circuit breakers or damage transformers. This specific model functions without a built in breaker, making it a direct OEM