TÜV/CE safety valves for heating and cooling
Series 355bHL

Rueckruf EN

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Safety valves with bellows made of GGG 40.3 spheroidal graphite cast iron with flange connections

Proven technology comprising of various materials for the most varied requirements: This valve made of spheroidal graphite cast iron GGG40.3 is a cost-effective alternative to the corrosion-resistant versions made of gunmetal or stainless steel.
These safety valves are not only used for the protection of large-scale heating plants in building technology but also for industrial applications and power stations.

  • 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 for all static heights or rated output above 350 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.
As these valves are completely made of metal, they can also be installed at high environmental or radiation temperatures.

  • heating systems for building technology and industrial applications
  • co-generation plants (CHP)
  • biogas plants
  • district heating transfer stations, building sub-stations

Safety valves are set and sealed at the factory.


TÜV Type test approval 2007

EU type examination

TSG ZF001-2006

TR ZU 032/2013 - TR ZU 010/2011

TRD 721
AGFW 505
DIN 4751 Part 2
DIN EN 12828
DIN EN ISO 4126-1
PED 2014/68/EU

Suitable for

Spheroidal graphite cast iron
DN 15 to DN 100
- 10°C to + 120°C
0,5 - 25 bar
Data sheet/Capacity table