Steam boiler sight glass: this article describes how to find & use the sight glass (or sight gauge) on a steam heating boiler to check or set steam boiler water level 

Liquid Level Sight Gauges & Water Gauges | Boiler Supplies

View the water level in your boilers or tanks with liquid level sight gauges and boiler water Kenco Liquid Level Gauges Safeguard Glass Protection Series.

Steam boiler sight glass: this article describes how to find & use the sight glass (or sight gauge) on a steam heating boiler to check or set steam boiler water level 

View the water level in your boilers or tanks with liquid level sight gauges and boiler water Kenco Liquid Level Gauges Safeguard Glass Protection Series.