APV DELTA SW4, Manual

Page: 17 / 70

See section 3 for disconnecting the valve.
The valve should be installed in such a manner that liquids can drain
off the valve body, i.e. preferably in vertical position.
Shut-off valves: the valve body can be welded directly into the
pipeline (valve insert can be dismantled
completely).
Change-over valves: the upper body must be installed in the
pipeline by means of a removable flange or
clamp connection.
See weight on page 61
Please note: Observe welding instructions.
2.1 Welding instructions
Shut-off valve:
Before welding of the valve, the valve insert must be removed from
the body. Handle carefully to avoid damage.
Change-over valve:
Before welding of the valve, the valve insert must be removed from
the body. Moreover, the lower body seal must be removed. For this
purpose, detachable connections (flanges, clamps, etc.) must be
provided in the pipelines to ensure that dismantling of the two bodies
and, thus, access to the lower seal is possible. Handle carefully to
avoid damage to the parts.
Welding may only be carried out by certified welders (EN 287-1).
(Seam quality EN 25817 "B")
When welding the valve bodies please make sure that deformation
strain cannot be transfered to the valve body.
The preparation of the weld seam up to 3 mm wall thickness must be
carried out as butt weld, as a square butt joint without air. (Consider
shrinkage!)
TIG orbital welding is preferable.
After welding of the valve bodies or mating flanges for instance after
work at the pipelines, the corresponding parts of the installation or
pipeline must be cleared of welding residue and contamination. If
these cleaning instructions are not observed, welding residues and
dirt particles may settle in the valve and cause damage.
Any damage resulting from nonobservance of these welding
instructions is not subject to our guarantee.
2 Installation
19