If 1" or 1.25" tubes in the main generating bank are married, the tube joints must be tested at which percent of boiler steady state pressure and satisfactorily pass hydro in order for no corrective action to be taken?

For tube joints in the main generating bank, testing at 100% of the boiler steady state pressure is required to ensure the integrity and reliability of the joints. Hydrostatic testing at this full pressure is critical because it simulates the actual operating conditions the boiler will face. This level of testing helps to verify that joints do not have leaks or structural failures under the highest anticipated pressure.

Testing at full pressure guarantees that any potential defects in the joint will be identified before the boiler is put into service. If the tube joints can withstand this pressure without any failures during the hydro test, it means they are deemed safe and reliable for operation.

Testing at a lower percentage, such as 75% or 90%, may not provide an adequate safety margin, potentially allowing weak joints to pass that could fail during normal operation, leading to safety hazards. Therefore, passing the hydro test at 100% mitigates risks and ensures operational reliability in daily use.