356 / 357 type approval (D/G) (steam/gas), spring loaded for steam and gas and other heating systems according to EN 12828 / TRD 721

As safety valves for steam, gases and hot water
in pressure vessels and steam boilers. Application
also in accordance with DIN 4752.

 

Range of use:

  • Grey cast iron                      up to 300°C
  • Spheroidal graphite iron      up to 350°C
  • Cast steel                             up to 400°C
  • Stainless steel                      up to 550°C

 

THIES High-efficiency Safety Valves meet the following German requirements: Pressure Vessel Safety Regulations, AD Specification A 2 for „Safety Valves", the Technical rules for steam boilers (TRD) and the Safety Valves Code.

 

Construction:
Spring loaded high-efficiency safety valve, angled.

  • Series 356 gastight version. 
  • Series 357 version with closed bonnet.

 

Liftable valve head. Force is transmitted centrally at the valve head via ball. Corrosion-resistant spindle guides ensure reliable and precise response of the valve.

Flange connections:
Grey cast iron version: inlet and outlet as per  DIN 2533 PN 16
Spheroidal graphite iron version, cast steel version and stainless steel version:

  • inlet as per DIN 2545 PN 40
  • outlet as per DIN 2543 PN 16

 

The safety valves are provided with a drain plug:

  • up to DN 50 - R 1/4 ".
  • over  DN 65 - R 3/8 ".

Models  356 / 357                                                                              Order Code No.

  • Series 356 of grey cast iron                       PN 16    300°C     356 GN
  • Series 357 of grey cast iron                       PN 16    300°C     357 GN
  • Series 356 of spheroidal graphite iron    PN 40    350°C     356 GGG up to 20 bar
  • Series 356 of spheroidal graphite iron    PN 40    350°C     356 GH over 20 bar
  • Series 357 of spheroidal graphite iron    PN 40    350°C     357 GGG up to 20 bar
  • Series 357 of spheroidal graphite iron    PN 40    350°C     357 GH over 20 bar
  • Series 356 of cast steel                              PN 40    400°C     356 SNC up to 20 bar
  • Series 356 of cast steel                              PN 40    400°C     356 SH over 20 bar
  • Series 357 of cast steel                              PN 40    400°C     357 SNC up to 20 bar
  • Series 357 of cast steel                              PN 40    400°C     357 SH over 20 bar
  • Series 356 of stainless steel                     PN 40    550°C     356 EN