Safety valve requirements for heating and air conditioning systems.
The TRD 721 is the governing standard for the heating and air conditioning industry. In sections 5 and 6 the specific requirements for safety valve design are established:
- TRD-721 section 6 for water heating plants up to 120° C with soft seal discs and elastomer bellows.
- TRD 721 section 5 for steam producers up to 1 bar overpressure with metallic sealing disc and elastomer bellows.
Because of extensive product standardization, short delivery times are common.