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LF31 Pressure Switch (37-8500 Pa)
Product Details

LF31 switches offer pressure, vacuum and differential models capable of sensing very low setpoints, and switching current up to 5Aresistive,2.5Ainductive. Designed for use in the HVAC industry, where reliable air proving is critical to both performance and customer safety, the LF31 is a favorite with leading manufacturers of gas-fired warm air furnaces and water heaters.

Smaller and lighter than any other HVAC pressure switch, the LF31 is built for the same temperature range and operating life as conventional switches made of stamped steel.

The LF31 will perform equally well in other applications which demand low OEM unit cost, robust design, setpoint accuracy, and high reliability.

The LF31 features a unique integral snap switch, with positive snap action and self-wiping silver contacts for ultra-reliable switching. The molded silicone diaphragm converts very low pressure or vacuum into movement of an actuator disk, which operates the silver alloy contacts.




Air , products of combustion, L.P. or natural gas

Operating Pressure Range

0.15" W.C. to 34" W.C.

Proof Pressure

100" W.C. (3.6PSI)

Operating Temperature

-40° C to 85° C

Contact Arrangement


Electric Rating

Resistance: Initial: <50 milliohms

Current: 100mA minimum,5Aresistive maximum

(fine silver alloy contacts);

15mA minimum,0.5Aresistive maximum

(gold-platinum-silver alloy contacts);


0.032" x 0.250" copper alloy


Inlet 0.25" for tube connection

Agency Approval

UL353, CE( EN1854: 2006, 13611: 2000)

Conversion: 1"W.C.= 1 inch/H2O=249Pa 1mbar=100Pa

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