At what percentage should a boiler be hydrostatically tested?

A boiler should be hydrostatically tested at a pressure of 150% of its maximum allowable working pressure (MAWP). This testing ensures that the boiler can handle pressures beyond its normal operating conditions and helps in identifying weaknesses or defects in the boiler's structure, such as leaks or material weaknesses.

Conducting the test at this increased pressure provides a safety margin and is essential for confirming the integrity of the boiler and its components. Testing at 150% allows for the assessment of the equipment's durability and operational safety, ensuring compliance with regulatory standards and enhancing the reliability of the boiler system.

Testing at higher percentages, such as 200% or 250%, may not be practical or necessary, and could potentially lead to undue stress on the boiler equipment, risking damage and possibly voiding warranties or insurance coverage. Therefore, establishing 150% as the standard benchmark for hydrostatic testing strikes a balance between safety and operational reliability.