8
APV_SW4_UK-4_082017.indd
UK
Single seat and change-over valve
DELTA SW4
Instruction manual: UK - rev.4
APV
7. Installation
7.3.
Welding Instructions
Shut-off valve
- Before welding of the valve, the valve insert must be dismantled
from the housing. Careful handling to avoid damage to the parts
is necessary.
Change-over valve:
- Before welding of the valves, the valve insert must be dismantled
from the housing. The lower housing seal must be removed.
Careful handling to avoid damage to the parts is necessary.
- Welding should only be carried out by certified welders (DIN EN ISO
9606-1) (seam quality DIN EN ISO 5817).
- The welding of the valve housings must be undertaken in such a
way that the valve body is not deformed.
- The preparation of the weld seam up to 3 mm thickness must be
carried out as a square butt joint without air.
(Consider shrinkage!)
- TIG orbital welding is best!
- After welding of the valve housings or of the mating flanges
and after work at the pipelines, the corresponding parts of the
installation or pipelines must be cleaned from welding residues
and
soiling.
If these cleaning instructions are not observed, welding residues
and dirt particles can settle in the valve and cause damage.
- Any damage resulting from the non-observance of these welding
instructions is not subject to our guarantee.
- Welding directives for aseptic applications shall be drawn from the
AWS/ANSI Directives and EHEDG Guidelines.