widos 4600 - Page 22

Starting and Operating Chapter 5
30.08.19 Working Instructions WIDOS 4600 Page 22 of 32
 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 wall
thickness, the admissible gap must not exceed 0.5 mm.
The mismatch compensation is carried out by further tightening or releasing the clamping nuts.
In case mismatch compensation was carried out, planing must be repeated afterwards.
 The adjustment pressure for the pipe dimension to be welded can be gathered from the table. Add
the movement pressure.
Set the resulting pressure value at the pressure limiter valve and check it by actuating the valve
lever.
 Open slides again slightly.
 Gather heating time, maximum change-over time, cooling down time and bead height for the pipe
dimension to be welded from the table.
 Move the heating element, which has been cleaned and brought to desired temperature, between
the pipes, take care that it lies in the zone of the throat of the tear-off bar (see point 4.3 ).
 Close slides smoothly to the set adjustment pressure.
When the prescribed revolving bead height is reached, reduce pressure. For this purpose, move the
valve lever to the position „pressure-less“ until the desired heating pressure is built up (heating
pressure = approx. 10% of the adjustment pressure).
 The heating time starts now. Press the stop-watch and compare the actual time with
the nominal time taken from the table.
 After expiration of the heating time, open the slides, remove the heating element as
quickly as possible, put it into the protection box and close the slides smoothly.
The maximum time frame for this process is predetermined by the value for the change
over time taken from the table.
 When the welding pressure is built up, press the stop-watch and keep the control
lever for approximately 10s on the position „pressure“ so that the hydraulic accumulator
can be filled. During the cooling time re-adjust pressure, if necessary (the pressure
for cooling is the same as the set adjustment pressure).
 After expiration of the cooling time, release pressure, remove the welded parts
and open the slides.