Issue 02
Düker GmbH, www.dueker.de
6
The valve must installed in a horizontal pipeline, with the stem in vertical position.
The valve should have adequate floor support.
Both welding studs must not be shortened.
Make sure that the surfaces in the welding area are bare metal, free from zinc and dry.
To prevent a strong heating of the sealing wedge, the valve must be fully open.
In no case, the stem may be used as the opposite pole, but only the pipe to be welded.
The valve must be welded in free of tension
The valve should only be closed when the housing is no more than lukewarm.
Check the weld seam during the pressure test of the pipeline.
Adjust the length of the blow-off pipes to the covering height.
Then insert the blow-off pipes into the free pipe ends of the valve and weld them on. Observe the
welding instructions.
When using detergents and disinfectants it must be ensured that these products do not attack the
materials and gaskets of the valve.
During the pressure test of the pipe system with the installed valve, the following test pressures may
not be surpassed:
Valve opened: The test pressure must not exceed 1.5 x PN (see type plate).
Valve shut: The test pressure must not exceed 1.1 x PN (see type plate).
The valve must be protected from dirt which can derive from work (e.g. painting, masonry and concrete
work) in the area of the valve.
4.1 Venting function
To vent the system, unscrew the plug on the ball valve.
When the gas line is filled, the ball valves are opened and the air in the pipeline can escape.
When this air
has been removed, the ball valve is closed, the plugs screwed back on and the system is ready for
operation.
When repairing the gas line, the corresponding part of the pipeline system is shut off.
The gas is vented through the venting tubes. The system is then purged with nitrogen.
This ensues that the remaining gas residues are thoroughly removed. Safe working is possible on the gas
line. The venting is as described above.