What is the minimum necessary range for a pressure gauge compared to the safety valve's set pressure?

The minimum necessary range for a pressure gauge is set to be one and a half times the safety valve's set pressure. This requirement ensures that the pressure gauge can accurately read pressures in a range that goes beyond the normal operating conditions of the boiler, allowing for a buffer above the safety valve's set pressure.

By having a gauge range that exceeds the safety valve pressure by this factor, it provides operators with a reliable means to monitor and assess the boiler's operating conditions while ensuring that any potential fluctuations in pressure do not lead to a situation where the gauge could be maxed out or damaged. This range not only enhances the safety and effectiveness of the pressure monitoring system but also aids in the timely detection of conditions that could lead to a safety hazard, thus prioritizing operational safety.