Under what condition shall mufflers not be used on safety relief valves according to ASME Code?

Mufflers are not permitted on safety relief valves for high-temperature water boilers according to ASME Code due to safety concerns related to the potential for vapor lock or the obstruction of safety valve operation. High-temperature systems can generate steam or hot water that, if muffled, may not vent properly during safety relief scenarios. The sound reduction provided by a muffler could mask the audible indicators of valve operation or failure, posing significant risks in cases of overpressure conditions. This particular specification is critical to ensure that safety relief valves function effectively and that operators receive necessary audible warnings when these valves are activated. The emphasis on preventing obstruction of the relief path in high-temperature scenarios is paramount to maintaining system safety and reliability.