Fusible plugs, CLASSIC line

Fusible plugs are safety devices that contain a material that melts at a specific temperature and consequently vents the pressure. Safety accessories for use with the following ASHRAE 34:2019 refrigerants, Class A1:
HCFC (R22)
HFC (R134a, R404A, R407C, R410A, R507)
HFO (R1234ze)
HFO + HFC (R448A, R449A, R450A, R452A, R513A, R515A, R515B)

Alloy melting point 79 °C for plugs in series 3080. Alloy melting point 138 °C for plugs in series 3082.