The correct answer is B (1.5 times the MAWP) because pressure vessels are typically designed and tested with a safety margin above their Maximum Allowable Working Pressure (MAWP) to ensure structural integrity under operating and upset conditions.
According to CCPS and widely accepted engineering codes such as ASME, pressure vessels are often hydrostatically tested at approximately 1.3 to 1.5 times the MAWP . This provides a safety factor to account for uncertainties such as material imperfections, corrosion, fatigue, and unexpected pressure surges.
The MAWP represents the maximum pressure at which the vessel is allowed to operate safely under normal conditions. Designing and testing above this limit ensures that the vessel can withstand occasional excursions without failure.
Option A (10 times) and C (4 times) are unrealistically high and not practical for engineering design. Option D (1 times MAWP) would provide no safety margin, which is unacceptable in pressure vessel design.
CCPS emphasizes the importance of design margins and conservative engineering practices to prevent catastrophic failures, ensuring that equipment can safely handle both normal and abnormal operating conditions.