Dwyer Instruments 475-2-FM Manometer 322056-301 the critical level (CL) must

the critical level (CL) must be installed at least 6 inches above the flood rim of the fixture

Always use genuine A

The system should be near operating pressure during this test to flush the seating surface effectively

even in high-temperature steam environments

Dwyer Instruments 475-2-FM Manometer 322056-301 the critical level (CL) mustFor veteran HVACR technicians and industrial contractors, the Dwyer Instruments 475 2 FM Manometer is the trade standard for measuring differential pressure in demanding environments. This intrinsically safe digital manometer is FM approved for use in hazardous locations (Class 1, Div. 2, Groups A, B, C, D, T4), making it the go to tool for monitoring natural gas pressure on boilers and combustion equipment. With a versatile range of 0 to 40. 00" w.