13
lamp (3) light up. The machine requires
about 10 minutes to heat up. Once the
required preset temperature is reached,
the built-in thermostat cuts out the power
supply to the heating element. The red
indicator lamp continues to glow.
The green temperature indicator lamp lights
up intermittently, indicating the repeated
switching on and o of the power supply.
After a further 10 minutes waiting time, (DVS
2207, Part 1), welding operations can begin.
Preheating of the sleeve welding unit
As soon as the connecting lead is
connected to the mains, the welding unit
begins to heat up. The green power-on
indicator lamp (3) and the red temperature
indicator lamp (4) light up. The unit requires
about 10 min. to heat up.
Once the required temperature is reached,
the built-in thermostat cuts o the power
supply to the heating element. The red
temperature control lamp turns o.
Whenever the red temperature control lamp
is lit, the no welding should be carried out.
1.6. Selecting the correct welding
temperature
The welder heating element is preadjusted
to the avee welding temperature for PP
pipes (260°C). Depending on the pipe
material and gauge of the pipe walls, it may
be necessary to adjust this temperature.
In this case, observe the manufacturer’s
information on the pipes or mouldings
without fail. In addition, the temperature
of the welding tools (spigot and socket)
should be checked with an electric surface
thermometer.
If necessary, the temperature can be
adjusted by turning the temperature
adjusting screw (6). In this case, it should
be remembered that the heating element
must not be used until 10 minutes after the
preset temperature has been reached.
2. Operation
2.1. Description of process
In welding with the sleeve welder, the pipe
and sleeve are welded together
overlapping. The end of the pipe and
moulded sleeve are heated to welding
temperature by means of the welding
tool (spigot and socket), then welded
together. The end of the pipe and tting are
matched to the welding spigot and socket
respectively in such a way that a build-up of
pressure takes place in the joint when the
two components are mated.
Guideline DVS 2208 species two methods
of sleeve welding in cases where the heated
spigot and socket are of dierent sizes.
In the case of method A, no provision is
made for any mechanical pre-processing
of the pipe, while in the case of method
B, the pipe is mechanically stripped. The
MAKALON spigot and socket are congured
solely for method A, i.e. no mechanical pipe
processing is required.
Sleeve weldings can be made manually on
pipes up to and including diameters
of 50 mm. With larger pipes, a suitable
welding machine must be used because
of the increasing forces required to achieve
the joint.
2.2. Preparations for welding
Take care to observe the information
issued by the manufacturer of the pipes
or mouldings. The end of the pipe must
be cut o square and at, either with a
pipe cutter or pipe shears. In addition,
the end of the pipe should be chamfered
to facilitate insertion into the socket. This
process should be performed with the
pipe chamfering unit. Immediately before
welding, the end of the pipe and interior of
the sleeve and, if necessary, the heating
spigot and socket should be cleaned with
non-adherent paper or a non-fraying cloth
and spirit or industrial alcohol.
In particular, no remnants of plastic must be
left adhering to the coating on the heating
spigot or socket. When cleaning the welding
tools, take care to ensure without fail that
their anti-adhesive coating is not damaged
by tools. The welding surfaces must not be
touched again before welding takes place.
2.3. Welding process stages
2.3.1. Heating-up
For the heating-up process, the pipe and
moulding are pushed axially onto the
welding tools in a continuous movement
until they reach the stop or the marking
on the tools. The heating-up time specied,
colunn 2 must be observed.
During the heating process, heat penetrates
into the joint faces and brings them
up to welding temperature.
2.3.2. Changeover and joining
After the heating process, the pipe and
moulding are pulled away from the welding
tools in a series of jerks and pushed
together, without twisting, as far as they will
go. The changeover time specied, column
3 must not be exceeded, otherwise the joint