28-09-2016· If you have a boiler set at 7 psi, the steam temperature is about 232 ° F. Steam traps will open once the steam temperature drops 10 ° to 20 °. The discharge temperature of the trap will be between 212 ° and 222 ° into a pipe at atmospheric pressure. At those temperatures, the water flashes to steam.
You start the boiler and allow the pressure to build. Once the pressure reaches your set point, 10 Psig, the burner shuts off. The burner stays off until the pressure inside the boiler drops to the differential (2 psi) setting minus the setpoint. In theory, our boiler will cycle between 8 and 10 psig.
Steam Heating Boilers Operating Pressure Settings Residential steam heating systems are almost always designed to operate at very low pressures, typically around 0.2 psi to a maximum of 0.5 psi - that' s 1/2 of one psi. Click to enlarge and you can see the actual pressure settings on the steam boiler control shown at left.
If you are happy to proceed, you can then repressurise your boiler using the following steps: Locate the filling-loop and pressure gauge. The filling loop handles should be at a 90° angle to the flow of the pipe. Check that you can see the pressure gauge whilst accessing the filling loop.
On a residential heating boiler the automatic water-feeder/pressure reducing valve that automatically provides makeup water to the heating boiler if pressure drops below 12 psi. So 12 psi is the typical "cold" pressure for residential boilers.