Unic URW295CR, Maintenance Manual

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(Description)
In order to ensure preventing the pistons of telescoping and derrick cylinders from becoming loose, fix the screw
threads on the rods and the pistons with the adhesive “LOCK TIGHT #638” (excepting for telescopic cylinders).
(Rods and pistons are to be fixed perfectly by application of adhesive “LOCK TIGHT #638”.)
(Main points)
Apply “LOCK TIGHT” to the entire circumference of 2nd to 3rd threads from the thread end.
Apply the primer as the gap in the effective diameter of threads exceeds 0.1mm.
Use type #7474 (primer T) for the primer.
(Although type #7469 is being used currently, type #7474 is more
effective as the target adhesion is to be at between metal components.)
Note : Pay special attention to observing the points to notice illustrated below while working
as curing itself and curing time of “Lock Tight” depends largely on how the adhesion
procedures have been carried out.
Points to notice on procedures to apply “LOCK TIGHT”
Procedures
1. Degreasing and cleaning →2. Priming coating →3. Application of “LOCK TIGHT” →4. Assembly 5. Curing
(1) Degreasing and cleaning
• Separate the oil well enough which has been applied to the threads (of rod/piston) to wipe it off with a
rag or blow it off with compressed air.
When blowing it off with air, remember that the unclean oil will not be blown off but will just escape along
the threads.
• In case of spray cleaning as well, target oil will not be removed but return if doing nothing but just spraying.
• After carrying out degreasing and cleaning, wait until cleaning fluid is dried up completely.
(2) Priming coating
• After primer #7471 has been applied, do not wipe it off but allow as it is for 5 10 minutes to dry naturally.
(Application of “LOCK TIGHT” without complete drying may result in reduction of adhesive strength by half.)
• Although a component primed is effective for 7 days, store it by preventing dust and/or oil from being stuck
before use.
• When “LOCK TIGHT” is applied to a component and it is shut off air, curing will start after 5 minutes from
application and will reach approx. 70% of curing in about 2 hours.
(Curing time will be shortened by priming, but theoretical adhesive strength will be 85% against a component
without priming.)
• Do not dip a primed component in “LOCK TIGHT” agent directly.
• Carry out priming at a place where well ventilated because priming agent escapes into air as vapor.
TELESCOPING/DERRICK CYLINDER ASS’Y, MEASURES
TOPREVENT PISTON FROM BEING LOOSENED
Rods and pistons are fixed by tightening after application of “LOCK TIGHT” to the threads on
the rods and on the pistons.
Besides, securing piston with screws and punching after application of “LOCK TIGHT #2701” are
also to be carried out as before
（１６－２）