25
Installation and Commissioning
Valve with Welding Ends
Valve with Welding Ends
This section describes the welding procedure for the valve.
WARNING
Spring tension in the valve
Danger of injury when opening the clips (43) as the released spring pretension will
suddenly lift the actuator.
Therefore, release the spring tension before detaching the clips by pressurizing the
actuator of a spring-closing valve with compressed air at max. 8 bar.
Carry out the following steps:
1.
Release the spring tension.
2.
Disassemble the valve, see chapter “Disassembling Valve N“ (Page 31) or “Disas-
sembling Valve W“ (Page 34).
3.
Fit the housing without sealing rings.
4.
Fit the housing into place and tack it.
5.
Always close the housing before welding.
6.
Flush the housing with forming gas from the inside to push the oxygen out of the
system.
7.
Weld the housing into the pipe system; use welding filler if necessary. Use the TIG
welding with pulse method.
8.
Passivate the seam after welding.
9.
Fit the seals.
10.
Assemble the valve and depressurize the actuator.
The valve disk is lowered.
Done.
NOTE
When assembling the valve always replace the housing O-rings to ensure that the valve
is tight.