ASME/ABMA Guidelines

Definition

Industry consensus limits from the American Society of Mechanical Engineers and the American Boiler Manufacturers Association for boiler water TDS, alkalinity, and silica by pressure range. They exist to prevent carryover.

The limits tighten as pressure rises, for example boiler water TDS below 3,500 mg/L at 0 to 300 psig versus below 1,000 mg/L at 901 to 1500 psig. They cap not scale but carryover, defining the upper boundary for safe cycling. Actual limits vary by boiler type and design, so operators defer to OEM, insurer, and steam purity requirements.

Related concepts

Alkalinity · Cycles of Concentration · Silica

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