New York Low Pressure Boiler COF Practice

What is the safety factor limit for a second-hand boiler with lap seam construction?

1. 4

2. 5

3. 6

4. 7

The correct answer is: 6

The safety factor limit for a second-hand boiler with lap seam construction is established at a value of 6. This specification is in recognition of the additional risks associated with second-hand boilers, particularly those featuring lap seams, which can be more prone to fatigue and failure than other constructions. Applying a safety factor of 6 helps to ensure that the operational limits of the boiler are well within a margin that promotes safety and reliability, taking into account potential weaknesses due to the seam type and the boiler's history of use. In general, second-hand boilers require more scrutiny due to their previous operational conditions. The lap seam construction, while commonly used in various applications, often faces scrutiny because the joints are welded together in a manner that can lead to vulnerabilities over time. Therefore, establishing a higher safety factor is prudent to account for uncertainties related to wear, corrosion, and any other factors that could compromise the structural integrity of the boiler.