Water Level Indicator Function: To indicate the level of water in the boiler constantly. It is also called water gauge. Description: Normally two water level indicators are fitted at the front end of every boiler. Where the boiler drum is situated at considerable height from the floor, the water gauge is often inclined to make the water level visible from any position. When the water being heated in the boiler transforms into steam the level of water in the boiler shell goes on decreasing. For the proper working of the boiler, the water must be kept at safe level. If the water level falls below the safe level and the boiler goes on producing steam without the addition of feed water, great damage like crack and leak can occur to the parts of the boiler which get uncovered from water. This can result in the stoppage of steam generation and boiler operation. Working: For controlling the passage of steam and water, cocks are provided. When these cocks are opened the water stands in the glass tube at the same level as in the boiler. There is a drain cock to blowout water at intervals so as not to allow any sediment to accumulate. Upper and lower stuffing boxes are connected by a hollow metal column. Balls are in the position in the normal working of the gauge. When the glass tube breaks due to rush of water in the bottom passage the balls move and shut off the water and steam. Then the cocks can be safely closed and broken glass tube replaced. There are screwed caps for internal cleaning of the passage after dismantling. It is tough and does not give splinters on breaking. Thus when the gauge glass breaks, and this guard glass which normally will hold flying pieces, also gives way, the pieces will not fly one and hurt the attendant.