Drum Level

Fig. 1: Gage Glass Drum Level Indication
Source: Book - Boiler Control System Engineering - GF (Jerry) Gilman

The designer of steam boiler should determine specific limit of drum level both for lowest level and highest level. Drum level must be maintained, do not reach highest or lowest level. If drum level exceed the highest level, the boiler water will be carried over into superheater and may damage turbine generator or steam boiler it self. High cost for maintenance is one of risks because of this condition. But on contrary, if drum level is low will lead to overheating either short term overheating or long term overheating. The most common occurs is crack or rupture in the tubes which connect to steam drum.

Fig. 2: Drum Level Transmitter
Source: Book - Boiler Control System Engineering - GF (Jerry) Gilman

Control drum level is very important to perform steam boiler continuously without damage or outage. Some equipments and instrumentations may be applied to monitor and control the drum level. These equipments are drum level differential pressure transmitter connection, gage glass drum level indication, electrode columns and drum level transmitter. These instrumentation must be located refer to code ABMA (American Boiler Manufacturer Association’s) – Recommendations for Location of Instrument and Control Connection for the Operation and Control of Water tube Boiler.