When hydro testing new boiler external piping, what is the required testing pressure?

The correct choice indicates that the required testing pressure for hydro testing new boiler external piping is 1 1/2 times the Maximum Allowable Working Pressure (MAWP). This standard is established to ensure the integrity and safety of the piping system.

When performing hydrostatic testing, it is crucial to apply a pressure that is significantly higher than the normal operating pressure (MAWP) to verify that the piping can safely handle the potential stresses it may encounter during operation. Testing at 1 1/2 times the MAWP allows for a sufficient safety margin to identify any leaks or weaknesses in the piping system without exceeding what would be considered a feasible limit.

This testing practice is based on common engineering principles that aim to enhance safety while avoiding unnecessary risks of failure. A pressure that is excessively high, as seen in the higher options, might not offer practical benefits and could introduce risks of damaging the piping. Thus, hydro testing at 1 1/2 times the MAWP is a balanced approach that both ensures safety and complies with industry standards for testing new systems.