When the maximum allowable working stress of a pressure vessel is adjusted, how does it affect the vessel design?

Adjusting the maximum allowable working stress of a pressure vessel directly impacts the design and safety considerations of that vessel. When the allowable stress is increased, the material can withstand greater loads before yielding or failing, which effectively raises the safety margin. This increased safety margin allows engineers to design the vessel with higher pressures or temperatures without compromising the structural integrity, which is essential for safe operation.

On the other hand, if the allowable stress were to decrease, the opposite would occur. A reduction in the maximum allowable working stress could potentially lower the safety margin, leading to a requirement for thicker walls or additional reinforcements to ensure that the vessel can still safely contain the specified internal pressures.

In this context, while other options may suggest various impacts of stress adjustment, they do not accurately reflect the primary effect of increased allowable stress, which is to enhance the overall safety and performance of the pressure vessel in its intended application.