b5a5d860_for_any_fuel_gas_fired__boiler__Item
[Safety] Two special relief valves vent steam from the boiler if the pressure reaches dangerous levels. [Reason] If the pressure controller and the high pressure switch shutdown circuit fail, these valves prevent excessive steam pressure from destroying the boiler. [Item] 
Boiler Steam Pressure Emergency Relief Valves
Safety controls for any fuel gas fired  boiler
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