TÜV/CE safety valves for heating and cooling
Series 651mHNK

Rueckruf EN

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Safety valves with diaphragm made of gunmetal, all-metal construction angle type with threaded connections

 651mHNK with enlarged outlet (TÜV/CE )
Robust safety valve with diaphragm with an all-metal construction. Designed to protect hot-water- and heating-systems.
This unmatched design, which does not have any plastic parts, means that these valves are also suitable for very high external temperatures.

  • Examples of use
  • Approvals
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For the protection of:

  • thermostatically protected closed-circuit water heating systems with flow temperatures of up to 120°C and a permissible heating output of up to 2.700 kW according to TRD 721, DIN 4751 and  DIN EN 12828.

Should the thermostatic limiting and control unit fail, the safety valve has to blow-off the total heating output of the boiler as hot water and steam. Thanks to the all-metal design these safety valves can also be installed in cases of high environmental or radiation temperatures.

  • heating systems for building technology- and industrial-applications
  • co-generation plants (CHP)

Safety valves are set and sealed at the factory.


TÜV Type test approval 516

EU type examination

TSG ZF001-2006

TR ZU 032/2013 - TR ZU 010/2011

TRD 721
DIN 4751 Part 2
DIN EN 12828
DIN EN ISO 4126-1
PED 2014/68/EU

Suitable for
Hot water
1/2" - 2"
- 10°C to + 120°C
2,5 bar and 3,0 bar
Data sheet/Capacity table