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16.0 Tube integrity and Lubrication
This is entirely the responsibility of the operator.
To be sure that the tube into which the cable is to be inserted is installed appropriately,
it is recommended that its integrity and lubrication be checked.
i.e. check that the tube is:
1. Not blocked
2. Not squashed
3. Continuous (i.e. it has not been fractured somewhere along its route and the
fractured ends separated)
4. Also check that any joins are pressure tight
5. Finally check that the tube is appropriately lubricated.
The easiest and most straightforward way to complete these checks is to set the
machine up for a normal cable insertion but fit a seal in place of the cable. The tube
can then be pressurised without running the roller drive.
CAUTION: ANY OBJECT INADVERTENTLY LEFT IN THE TUBE
DURING THE TUBE LAYING MAY BE EXPELLED FROM THE
END OF THE TUBE WITH HIGH FORCE AND VELOCITY. IT IS
IMPERATIVE THAT NO PERSONNEL BE IN THE VICINITY OF
THE END OF THE TUBE OR THAT A SUITABLE DEVICE IS
FITTED TO THE END OF TH E TUBE TO ARREST ANY
EXPELLED OBJECT.
The checks listed at 1-4 (inclusive) above may all be carried out at the same time using
one check. The procedure is outlined below.
Set up the air box and tube clamp as
shown right.
When the air box has been set up as
shown in the sketch. The air box and
tube clamp should be closed as for usual
cable installation.
Fit the appropriate plug as shown
(see Appendix for plug number)
Fit the air box seal, tube and tube
seal in position as for normal
cable installation
