What is the minimum relieving capacity percentage of a smaller high-pressure safety valve compared to a larger valve when mounted singularly on a boiler?

The requirement for a minimum relieving capacity percentage of a smaller high-pressure safety valve compared to a larger valve is significant in ensuring safety and regulatory compliance in boiler operations. When a smaller safety valve is installed for singular service on a boiler, it must be capable of relieving steam pressures effectively to prevent overpressure situations that could lead to catastrophic failures.

In this context, the correct answer indicates that the smaller valve must have at least 50% of the relieving capacity of the larger valve. This is crucial because it ensures that even when a smaller valve is utilized, it maintains a sufficient capacity to handle emergencies and safely discharge excess pressure. If a smaller valve had a lower relieving capacity percentage, it may not adequately protect the boiler system during high-pressure events, which could result in failure or explosion.

This requirement reflects industry standards and safety codes that demand proper sizing and capacity of safety valves to uphold the operational integrity and safety of pressurized systems. Using a smaller valve with this minimum capacity ratio helps to mitigate risks associated with high-pressure systems while facilitating safe operations within acceptable limits defined by regulatory bodies.