During a hydrostatic test, the pressure applied on the boiler should be what factor of the MAWP?

The pressure applied during a hydrostatic test is indeed typically set at 1.5 times the Maximum Allowable Working Pressure (MAWP) of the boiler. This testing method is crucial for verifying the integrity of the boiler's structure and its capability to withstand operating pressures.

The rationale behind using 1.5 times the MAWP is to establish a safety margin that ensures the boiler can endure fluctuations in operational conditions and thermal expansion during its service life. Hydrostatic testing involves filling the boiler with water and subjecting it to this increased pressure for a certain period, allowing for the identification of any weaknesses, leaks, or structural defects in the boiler. The water is used instead of air or gas for safety reasons, as water is incompressible, meaning there is a minimal risk of explosions if a failure occurs.

This testing standard is part of a broader set of guidelines and codes that help ensure safe operation and reliability of pressure vessels, thereby protecting both the machinery and the personnel involved in their operation.