Which form of safety valve mounting is prohibited in the heating boiler code?

The choice indicating that mounting a safety valve to an internal pipe in the boiler is prohibited aligns with safety and operational standards set forth by boiler codes. Safety valves are critical components designed to prevent overpressure in boilers by releasing excess steam or water. Mounting a safety valve directly to an internal pipe of the boiler could pose significant risks, including the potential for the valve to malfunction due to the unique pressures and temperatures present within the boiler itself.

The prohibition of this mounting method ensures that the safety valve operates effectively and maintains its integrity under extreme conditions. Additionally, this regulation helps prevent issues such as thermal expansion or localized overheating, which might lead to a failure of the valve or the piping system.

Proper mounting practices for safety valves typically involve external piping systems or directly on the boiler's required discharge points, allowing for optimal performance and safety compliance. This design ensures that the safety valve can function correctly in relieving pressure while minimizing the risk of malfunction or failure due to the extreme conditions encountered inside the boiler.