GOETZE · Safety Valves
GOETZE 651mHNK diaphragm safety valve for heating systems
All-metal gunmetal diaphragm safety valve for closed hot water heating systems to 120 °C and 2,700 kW, 1/2" to 2" with enlarged outlet, 2.5 or 3.0 bar, TÜV H type tested under TRD 721 and EN 12828; 651mHNK VA variant with stainless steel wetted parts.
The 651mHNK is GOETZE’s diaphragm safety valve for closed hot water heating systems: TÜV type tested as an H valve under TRD 721, DIN 4751 and EN 12828 for flow temperatures to 120 °C and boiler outputs up to 2,700 kW. If the thermostatic limiter and controller fail, the valve discharges the full boiler output as hot water and steam. The construction is all-metal, so it can sit next to boilers and CHP engines where ambient or radiation temperatures are high.
Set pressures are the fixed 2.5 and 3.0 bar of heating practice, the outlet is one size larger than the 1/2” to 2” inlet, and the EPDM diaphragm and seal tolerate glycol mixtures up to 100 %. The 651mHNK VA is the 1/2” version with a stainless steel body and wetted parts for aggressive water qualities. For heating systems above 120 °C, GOETZE refers to the 451bG and 851bG bellows valves.
Selection data we need
Boiler output, set pressure (2.5 or 3.0 bar), inlet size, glycol content and whether stainless steel wetted parts are required. For a replacement, the type code and nameplate data are enough.
Applications
- Heating systems in building technology and industry
- Co-generation plants (CHP)
- Boilers with high ambient or radiation temperatures
- Systems with up to 100 % glycol
