Priming

Definition

Mechanical carryover that occurs when the boiler water level physically surges and liquid water is pulled or splashed into the steam outlet. It is a mechanical, not chemical, problem.

Priming is triggered by a sudden increase in steam demand, a failed level controller, or a rapid load swing. In a school district case, simultaneous morning thermostat increases caused the boiler to fire hard from low load, producing violent turbulence and surging that pulled water into the header even though the chemistry was within every guideline. The cure is mechanical control of load and level, not chemical treatment.

Related concepts

Carryover · Water Hammer · Foaming

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Part of The Blueprint of Water · 🛠️ operations