GOETZE 451 stainless steel angle safety valve, threaded

The 451 is GOETZE’s standard stainless steel safety valve and the reference type of the whole threaded range: an angle valve with 1.4404 inlet body and internals, 1/2” to 2”, and set pressures from 0.5 to 70 bar for steam, gases and liquids. It goes where gunmetal reaches its limits, in chemical and biogas plants, steam boilers, sterilizers and autoclaves, on bulk transport vehicles and in hydrogen service.

Four bonnet versions cover the media: an open bonnet for neutral media, a bellows version that compensates back pressure up to 8 bar and keeps spring and guide away from the medium, a gastight bonnet for non-neutral media, and the double gastight bellows version for flammable, toxic or environmentally hazardous media. Seals range from NBR to metal-to-metal for −60 °C to +400 °C, connections are BSP, NPT or DIN 32676 clamps. The valve is TÜV type tested, ASME UV stamped, CRN registered, DVGW hygiene listed with EPDM seals and approved by the main classification societies.

Three variants serve building and heating technology: the 451bG for solar and district heating primary circuits above 120 °C, the 451bH for hot water heating systems to 120 °C under TRD 721 and EN 12828, and the 451bHF for combined heating and cooling circuits down to −40 °C. The flanged version is the 451FL, the gunmetal version the 851.

Selection data we need

Medium and state, set pressure, required discharge capacity, operating pressure and temperature, back pressure, inlet and outlet size and connection type, seal material and bonnet version (open, bellows, gastight). For heating systems, the boiler output. For a replacement, the type code and nameplate data are enough.