Adjustable pressure controller L91 series

L91 Proportioning Pressuretrol® Controllers are Series 90 Modulating Pressure Controllers that provide direct control of modulating motors or valves used on automatic burners or steam heating systems. Features & Benefits: Models available for pressure systems up to 300 psi (2068 kPa) May be used with steam, air, noncombustible gases, or other fluids noncorrosive to brass or phos-bronze (300 psi model) bellows When used with steam boilers, a steam trap (siphon loop) is recommended Wiper on controller potentiometer moves in response to pressure changes L91D has two potentiometers for unison control of two motors L91B,D models have adjustable proportioning (throttling) range to allow selection of desired pressure control range Adjustments made with screws on case top Large, easily-read scaleplates in both U.S. customary (oz/sq. in., psi, or in. Hg) and metric (kPa, MPa, or mm Hg) units Steel case with clear plastic cover to observe pressure settings and potentiometer action Fitting with 1/4 -18 NPT threads allows rapid installation Surface mount with screws through knockout holes back of casing