Steam Water Boiler Components

Steam Boiler

Heats water into steam

Header

Horizontal pipe that allows for flow of steam from boiler to supply main

Supply Main

Carries steam from boiler to radiator

Risers

Vertical pipe that directs steam to radiators

Angle Valve

Controls steam to radiator that should be fully open OR closed

Radiator

Transfers heat to from boiler to living space

Air Vents

Vents air from radiator

Flow & Temperature Trap (F&T Trap)

Vents air, traps steam, allows condensate to flow

Main Air Vent (Quick Vent)

End of supply main, auto vents air

Dry Return

Above water level, directs condensate back to boiler

Wet Return

Below water level, directs condensate back to boiler

Hartford Loop

Prevents drainage/low water levels in boiler

Blowdown Valve

Removes impurities in boiler

Sight Glass

Shows water level of boiler

Low Water Cut-off

Shuts off gas valve when boiler water level is low, senses drop in water level

Water Feed Valve

Adds water to boiler if it is low

Vent Damper Motor

Prevents heat loss out the venting system during off cycle

Pressure Relief Valve

Reliefs pressure when it exceeds 15 psi

Thermostatic Trap

Traps steam in radiator

Pressure Switch

Controls boiler pressure

Pressure Gauge

Measures boiler pressure

Thermostat

Controls living space temperature

Draft Hood

Creates down draft

Spill Switch

Shuts burners off if vent is clogged/blocked

Combination Gas Valve

Auto controls gas to burners

Pigtail Siphon

Prevents steam contact with pressure switch