Threaded Joints
An extensive range of threaded
fittings are available mostly having
parallel threads to relevant
standards.
Tightening of threads should only be
done by hand or at most by an extra
quarter turn with a strap wrench.
Extra care must be taken not to over tighten or damage the fitting component.
Pipe wrenches must not be used in any circumstances.
It is recommended that PTFE tape should be used in the jointing of threaded
fittings to complete a satisfactory seal.
Please note under no circumstances should a sealing paste be used which could
be harmful to either PVC-U or ABS products.
Cement
Joints
Prepare the fittings and pipe as follows:
- Cut the pipe at right angles to
its axis and to the required length. Deburr the cut end of the pipe and then
chamfer the leading edge of the pipe at approximately 30° – 40°.
This will prevent the solvent cement being wiped from both the pipe and the
fitting when pushed together.
- Dry fit the pipe to the socket of the fittings.
When the pipe is fully home in the socket, draw a line around the pipe
at the edge of the socket. Where this is not possible, measure the socket
depth and draw a line at the corresponding point along the pipe. This will
give a visual indication to ensure that the pipe is fully home in the socket.
- Roughen both
the pipe surface up to the indicator mark and the inside of the socket
with emery cloth, this will take off the shiny surface.
- Do not roughen both surfaces
of the pipe and fitting to the extent that the clearance between them is
noticeably increased.
- Degrease the surface of both the pipe and the fitting with a
lint free cloth or piece of absorbent paper dampened with Effast MEK Cleaner.
Ensure that both jointing surfaces are fully cleaned. Allow the cleaner
to evaporate, before applying the solvent cement. Any excess cleaner should
be quickly removed from the surface of the pipe or fitting as this may affect
the integrity of the system.
- Select the correct solvent cement. Do not attempt
to solvent weld PVC-U Pipe and fittings with ABS cement or vice versa.
ABS cement, will need to be thoroughly stirred before use, PVC does not.
- Apply
the solvent cement straight from the tin with a suitably sized brush. Ensure
that the roughened area in the socket and pipe up to the visual indicator
is completely covered with an even layer of cement. It is essential that
the excessive use of solvent cement is avoided. This part of the procedure
must be done quickly and neatly as the solvent cement must still be wet when
the pipe and fitting is pushed together.
- Push the pipe and fittings together and hold in place
for up to 30 seconds for smaller diameter sizes (up to 2"/63mm) and
up to 1 minute for larger sizes (2"/63mm – 12"/315mm). When
the joint is made a bead of cement will form between the chamfer of the pipe
and the central register of the fitting. This bead will help ensure the integrity
of the seal. Excessive deposits inside the fittings must be avoided as this
can weaken the wall especially on small sizes. A bead of solvent cement will
also form around the outer joint of the pipe and socket. This excess cement
should be wiped away leaving the outer part of the joint clean. Do not disturb
the joint for 10 – 15 minutes.
- After 8 hours under normal conditions
the cement within the joint will have dried enough to be able to withstand
the rated pressure of the pipe system, however, we would recommend leaving
the joint for the full period of 24 hours wherever possible. Please note
that all drying times in a pipe system only start on the completion of
the last joint. After 24 hours the pipe system can be fully pressure tested.
The test pressure should be equal to 1½ times the rated pressure of the
lowest rated fitting or pipe within the system.
- Please note that during the jointing
procedure both solvent cements and cleaners produce vapours (fumes),
therefore, we recommend that the jointing procedure should be undertaken
in a well-ventilated area. We also recommend ventilation within the pipe
system during assembly, to disperse any potentially harmful vapours.
The above information is given
as a guide, for further details please refer to our technical guide, which
is available upon request.
Do not
- Make joints in the Rain or Wet Conditions.
- Use dirty brushes or cleaning
rags, which are dirty or oily.
- Use the same brush for different solvent
cements.
- Dilute or thin solvent cements with MEK cleaner.
- Leave solvent cement
tins open.
- Use near a naked flame, or smoke whilst jointing.
- Make joints in a confined
space.