To what percent of normal boiler operating pressure must rerolled superheated tubes be hydrostatically tested?

Rerolled superheated tubes must be hydrostatically tested to 125% of their normal boiler operating pressure as a standard industry practice. This test is crucial for ensuring the integrity and safety of the tubes, which can experience significant stress during operation. By testing at this higher pressure, any potential weaknesses or defects can be identified before the equipment is put back into service. The additional pressure provides a safety margin, allowing for the verification that the tubes can handle the stresses of normal operation, plus some additional tolerance for safety.

This approach reflects a commitment to safety and reliability in boiler operations. Testing at less than 125% may not adequately ensure that the tubes are free of flaws or capable of withstanding operational pressures. Therefore, this standard is established not only to comply with regulatory requirements but also to uphold the safety of personnel and equipment in the steam generation process.