Ku nsts tof fsch wei ßte chni k
Starting and Operating
Chapter 5
12.02.04
Working Instructions WIDOS HRG 14, Segment
Page 21 of 42
5.4. Welding Process
The respectively valid w elding prescriptions (ISO / CEN / DVS ...) are to be basically
follow ed.
•
Wear safety gloves as a protection against burning !
•
A stop-w atch must be available for recording the actual times for heating and cooling.
•
A w elding table must be available from w hich the parameters for the pipe dimensions to
be w elded prescribed by the w elding prescriptions may be taken.
•
The heating element surfaces must be clean, especially non greasy, therefore they need to
be cleaned shortly before each w elding or in case of dirtiness by means of a fibre-free
paper and a cleaning agent (e.g. PE cleaner). The anti-adhesive coating of the heating
element must remain undamaged in the w orking area.
•
Sw itch on the heating element and set the required w elding temperature (standard value
for PE-HD: 210°C) at the thermoregulator.
-
If the control lamp blinks, the desired temperature is reached and maintained by a
certain pulse-position ratio.
•
Mount the reducer inserts according to the pipe outside diameter to be w elded.
•
Lay the pipes into the clamping devices and take care that the upper clamping rings are
mounted w ith the locking forks show ing to the machine center. Tighten firmly the clamping
nuts, respectively close the clamping cylinders and align the pipe ends w ith respect to
each other.
Alw ays use
WIDOS
rollerstands for alignment.
•
If need be cut plane (see point: 5.3)
•
Close the slides thereby reading the
movement pressure
on the pressure gauge.
The movement pressure is displayed exactly w hen the slide w ith the clamped pipe passes
over into its movement.
•
Check pipe mismatch and gap on the joining pipe ends. According to DVS 2207, the
mismatch on the pipe outer side must not exceed 0.1 x pipe w all thickness, the admissible
gap must not exceed 1.5 mm. The mismatch compensation is carried out by further
tightening or releasing of the clamping nuts.
•
The adjustment pressure for the pipe dimension to be w elded can be gathered from the
w elding table. Add the movement pressure.
•
Set the resulting pressure value at the pressure relief valve and check it by actuating the
valve lever.
•
Open slides again slightly.
•
Gather heating time, maximum change over time, cooling time and bead height for the
pipe dimension to be w elded from the table.
•
Move the heating element w hich has been cleaned and brought to desired temperature,
betw een the pipes, if necessary w ait until the control lamp on the heating element blinks in
regular intervals.
