Steam Boilers Safety Control

A steam boiler is capable of generating superheated steam having temperature more than 212 degrees F. However, this temperature can go beyond unsafe limits and result in fire breakout, if adequate safety controls are not incorporated within the boiler system. Hence, for safe and sound operation of steam boilers, following safety controls must always be provided:

• Limit switches: These are the safety switches which are basically included in the system to detect the increase of temperature beyond a certain limit. As soon as the temperature inside the boiler crosses the defined limits, a limit switch operates resulting in the shut down of the whole system. It is usually mounted near the draft diverters. It proves to be a useful device in preventing fire breakouts and plugging up of chimney or flue gases. It helps in avoiding carbon monoxide poisoning or any other dangerous situation related to temperature rise.
• Low water cut-off: This safety feature should always be incorporated in the boiler system for keeping a check on the level of water in the boiler. The normal level of water is in the half-way in the gauge/ sight glass which should always be maintained. For carrying out a regular visual inspection of water level, the sight glass indicating the level must be kept clean and free from dirt. Lower than average water level in the boiler may lead to undesirable results.
• Automatic water feeder: This device is generally employed for automatically feeding water into the boiler system whenever the water level drops below a certain point. Appropriate water level will result in generation of high quality steam heat. However, small adjustments are needed in the system to maintain correct water level i.e. neither too much high nor too much low. Since excess water will not heat up the system whereas scarcity of water may cause hazardous situation.
• Pressure cut-off control: Various devices such as pressure relief valves and blow-down valves etc. are employed in the boiler system for exercising control over excess steam pressures. 

 Type of Steam Boilers