What is the maximum operating pressure of a boiler drum made of SA-515-70 steel with a ligament efficiency of 0.66, at a steam temperature of 280°C and drum diameter of 1.6 m?

To determine the maximum operating pressure of a boiler drum made from SA-515-70 steel, it's important to consider the Mechanical properties of the material, the geometry of the drum, and the applicable codes or formulas for calculating pressure based on these factors.

SA-515-70 is a type of carbon steel commonly used in high-temperature and high-pressure applications, such as boiler drums. The allowable stress for SA-515-70 at elevated temperatures, specifically at 280°C, is critical for determining the maximum pressure. The ligament efficiency, in this case, is given as 0.66. This applies to how much of the wall of the drum can effectively carry the load due to the presence of openings (like manways or nozzles) that might reduce the strength of the structure.

Using the formula for maximum pressure (P), which incorporates the allowable stress (S) multiplied by the wall thickness (t) and divided by the internal radius (R), while factoring in the ligament efficiency (E), can help derive the maximum pressure. The formula is generally expressed as:

P = (S * E * t) / (R)

Here, for SA-515-70 at 280°C, the allowable stress would be found in