What is the required hydrostatic test pressure after the replacement of certain boiler components?

The required hydrostatic test pressure after the replacement of certain boiler components is established to ensure the integrity and safety of the system under operating conditions. The correct answer is that the hydrostatic test pressure should be 135% of the boiler design pressure. This percentage is designed to account for any potential weaknesses or failures in the new components due to factors such as material imperfections or improper installation. Testing at 135% provides an adequate safety margin beyond normal operational pressures, ensuring that the components can withstand and function safely under regular usage.

In the context of boiler safety regulations, testing at this elevated pressure helps to identify any leaks or weaknesses before the boiler is put into service again. This practice is crucial for maintaining operational safety and reliability in high-stress environments where boilers operate at elevated pressures and temperatures.