Get Steam Drum Level Measurement Form

Water level in a drum indicates the amount of water reserved in the drum-riser-downcomer loop of a natural circulation boiler, and is kept within a limited range for safety reasons.

The standard values of Boiler drum water level is1000 mm, the scope of change for 920-1080 mm. Measurable range of Boiler drum water level change is ±300 mm. Steam and water can be measured, steam decided by external load. Steam flow cannot be controlled; feed water flow can be controlled by water supply valve [2].

They are measured from the bottom tap of the steam drum. 2. Using the saturated steam tables, find the values of and at the drum operating pressure. Use the value for compressed water in the reference (wet) leg at the expected ambient temperature and the drum operating pressure.

The first and most important is the gauge glass. This gauge glass will be on the side of the boiler. It is a glass tube about ⅝” in diameter and about 8-10” high. A good rule of thumb is to see the water level about halfway up the gauge glass.

In package boilers, usually steam drum sizes are starting at 914 mm (36 in.). Well-known sizes are 1,067 mm (42 in), 1,220 mm (48 in), 1,370 mm (54 in), 1,524 mm (60 in) and, every so often, 1,676 mm (66 in). Lower drums identify as mud drums because of large volume of sludge.

The Normal Operating Water Level (NOWL) should be approximately in the middle of the gauge glass. Try cocks are used to determine the boiler water level if the gauge glass is not functional.

LEVEL MEASUREMENT The drum level is measured using a differential pressure transmitter. Refer to the drawing on the right. The output of the instrument increases as the differential pressure decreases. A typical range is 30 inches of water column.

The normal operating water level (NOWL) should be approximately in the middle of the gauge glass. All steam boilers must have two means to determine water level. The gauge glass is the first and easiest means.