What is the maximum length an internal inspection of an unfired steam boiler can be extended?

For unfired steam boilers, the maximum period that an internal inspection can be extended is indeed 84 months, or 7 years. This time frame is guided by safety regulations to ensure that these boilers remain in safe operating condition. Regular inspections are critical in identifying wear, corrosion, and other issues that may arise over time due to the properties of the materials and the operational stresses involved.

Extending the internal inspection to 84 months allows for a balance between ensuring the equipment is thoroughly checked for integrity and safety while recognizing that some units may experience lower levels of stress or usage, necessitating less frequent inspections. It is important for operators to adhere to this guideline to maintain compliance and ensure safe operation.