A fire valve is an essential part of the oil supply system. Its purpose is to cut off the flow of oil outside the building in the event of fire within the boiler area. The valve should be located at the point of entry into the building of the fuel line. It must be activated by a remote sensor located over the burner, a clip is provided within the appliance for the sensor.
Firebox Boiler is an internally fired firetube unit as like vertical tubular and scotch marine tubes. But its shell is horizontal and the firebox is not contained within the cylindrical portion of the boiler. The firebox is rectangular with a curved top known as a crown sheet. This crown sheet is supported by radial stays screwed into the crown sheet and the outer wrapper sheet. The inner sheets of the firebox are connected to the outer side sheets by stay bolts. The space between these sheets are called the water legs. The fire tubes are within the barrel and run from the firebox tube sheet to the smoke box head of the barrel. This head in the smoke box is formed by extending the barrel beyond the tube sheet.