catalogue - Düker GmbH & Co KGaA

6 Assembly
258
instructions for pressure pipes
and fittings with flanges
1. Cleaning of flange, raised face and gasket. Check all parts for proper conditions. Do not use
damaged parts.
2. In case of installation with unprotected screws, especially in soils with corrosion risk, the screw
connections must be protected ( f. e. with bitumous tapes ).
3. Pipes and fittings must be bedded carefully and the filling and compacting of the pipe ditch must
be done carefully as well. Pipes and fittings should never be supported with stones or similar
hard material and must be laid on stonefree base. Rocky base must be covered with min. 15 cm
layer of sand, gravel or split.
4. For flanged pipes and -fittings the general rule for the arrangements of the boltholes is, that no
bolthole is located in the flange axis, which is upright to the pipeline level.
5. Notes for the installation of flanges fittings ( in particular double flanged tapers / FFR ):
To avoid installation failures, special installation marks ( notches ) are cast on at the flanges in
opposite positions. It is necessary to pay attention that these marks are arranged for installation
in vertical or horizontal direction.
Example: Double flanged taper ( FFR ) 350 / 250, PN 10
right wrong
In case of wrong installation and in consequence to the different numbers of boltholes at double
flanged tapers, the connected valves or fittings are bevelled to the vertical axis. Possible deviations
are up to 22,5°, depending on the dimensions.
Attention:
On big dimensions, a deviation is hardly to detect!
Remarks:
Please note, that DVGW-workingsheet GW 368 should be observed.
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