What is measured by a static pressure sensor on the top of the boiler steam drum?

What is measured by a static pressure sensor on the top of the boiler steam drum?

• A. Steam drum pressure
• B. Boiler water temperature
• C. Feedwater flow rate
• D. Ambient air pressure

Answer: (A)

The sensor up there is reading the pressure in the steam space of the drum, i.e., the boiler’s steam pressure. This is static pressure—the force exerted by the steam when it’s at rest inside the drum. That pressure is what boiler controls monitor and regulate to maintain safe operation and proper heat transfer, fuel, and feedwater control. It isn’t measuring boiler water temperature (that needs a thermometer or thermocouple), feedwater flow (that would be a flowmeter in the feedwater line), or ambient air pressure (which isn’t directly tied to the boiler’s steam system).

The sensor up there is reading the pressure in the steam space of the drum, i.e., the boiler’s steam pressure. This is static pressure—the force exerted by the steam when it’s at rest inside the drum. That pressure is what boiler controls monitor and regulate to maintain safe operation and proper heat transfer, fuel, and feedwater control.

It isn’t measuring boiler water temperature (that needs a thermometer or thermocouple), feedwater flow (that would be a flowmeter in the feedwater line), or ambient air pressure (which isn’t directly tied to the boiler’s steam system).