What is the minimum steam drum pressure on an operating boiler?

The minimum steam drum pressure on an operating boiler is essential for ensuring system efficiency, safety, and the ability to maintain the necessary thermal cycle. A steam drum typically needs to operate at a pressure that allows for effective steam separation, proper water level management, and stable boiler operation.

For a steam boiler to function properly, the drum pressure must be maintained at a level that is at least 85% of the boiler operating pressure. This ensures that the steam is adequately saturated and has sufficient energy to be delivered for work, such as in turbines or heating processes. Operating below this threshold might lead to issues such as poor heat transfer, excessive water carryover into the steam lines, or even operational inefficiencies that could put the system at risk.

While pressures below this level may seem sufficient under certain conditions, they do not cater to the full performance and safety requirements associated with boiler operation. Therefore, maintaining the steam drum pressure at 85% or greater of the boiler's operating pressure is a standard practice, ensuring reliable and effective performance of the boiler system.