Pressuretrol

Heating · Components and Problems · printed page 196 (PDF page 197)

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Book index entries

Pressuretrol for Steam Heat Steam Heat – Pressuretrol Steam Heat – Systems

Text in the illustration

steam pressure limit switch (pressuretrol)
bellows
boiler
a bellows built into the bottom of the pressuretrol expands and contracts depending on the steam pressure
when the bellows expands to the set cut-out pressure, a switch that provides power to the burner is turned off
the pressure differential screw can be set so that the burner is reactivated when the steam pressure falls below the cut-in pressure
pigtail - protects pressuretrol mechanism from coming in direct contact with boiler steam by forming a trap for condensation
to boiler controls
steam
water level gauge
boiler water level
low water cut-out
automatic feeder valve
cross section

Generated explanation

This cross-sectional illustration shows a steam boiler with a pressuretrol, pigtail connection, water level gauge, low water cut-out, and automatic feeder valve. The pressuretrol connects to the boiler through a looped pigtail that traps condensation to protect the control mechanism from direct steam contact. Annotations explain that steam pressure expands the bellows, opening a switch to shut off burner power at the cut-out pressure; the differential adjustment determines when the burner restarts as pressure falls. The gauge water level aligns with the indicated boiler water level, and adjacent piping connects the low water cut-out and automatic feeder valve. No defective condition is depicted.

Components

steam boiler pressuretrol steam pressure limit switch bellows pigtail water level gauge low water cut-out automatic feeder valve connecting piping boiler control wiring