What is the purpose of having two or more safety valves on a boiler with a large heating surface?

Having two or more safety valves on a boiler with a large heating surface is fundamentally about ensuring safety under high pressure. In a boiler system, the pressure can rise significantly due to various factors like overheating or improper functioning of components. Multiple safety valves provide an additional layer of protection; if one valve were to fail or become obstructed, the other valves will still be operational to relieve excess pressure.

This setup is particularly critical in large boilers where the heating surface is extensive, and heat transfer can lead to rapid pressure increases. The safeguards in place prevent catastrophic failures, such as explosions, by ensuring that excess pressure can always be released. By having more than one safety valve, the system enhances reliability and compliance with safety standards, ultimately protecting both the equipment and personnel.

The other choices focus on different aspects of boiler operation, such as fuel efficiency, temperature regulation, and steam loss minimization, none of which directly relate to the primary function of safety valves. These factors are important in the overall management of boiler performance, but they do not address the critical safety role that multiple safety valves serve in preventing overpressure conditions.