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1.
Pipe spools are fabricated to proprietory drawings, considering
nominal bore size. Similarly jacketted pipe spools are fabricated.
2.
Approved weld procedures for flange attachment and setting
are adopted and welding is carried out by qualified welders.
3.
When fabricating pipes and fittings, end connections shall
be manufactured to provide a minimum 3 mm radius or chamfer
in the transition from pipe wall to flange or lap collar face.
This radius or chamfer is required to reduce stress concentration
in the plastic liner as it is flared or moulded over the flange
face or stub end.
4.
All Pipe spools have lap joint flange (Flange rotates on Pipe)
at one end and fixed flange at the other end.
5.
The interior surfaces of all Housings shall be clean and free
of burrs, rust, scale or other protrusions which may adversely
affect the integrity or performance of the lining.
6.
As a standard, Lined pipes are manufactured upto a max. length
of 3 mtrs in all sizes and for all liner material. Longer
lengths can be made available for which the factory has to
be consulted.
7. All fittings
are with fixed flanges either cast on or welded.
8.
All Pipes & Fittings must be vented in compliance with
ASTM F 1545. Vent Systems are designed to release any gases
between the liner and the housing - preventing build up of
those gases which could cause premature failure of the lined
system.
9.
Precaution should be taken to see that these vent holes are
left open at all times and care should be taken when painting
the pipe work during installation and maintenance. Each pipe
assembly and fabricated fittings are provided with vent holes
drilled (2 mm dia to 4mm dia) into the metal housing prior
to lining. Two pair of vent holes for each pipe spool 180oC
apart and located 150 mm from each flange
face are provided. Each pair of these vent holes are drilled
rotated 90o C to each other.
For pipe assemblies 500 mm or less only one pair of vent holes
located between the flanges are required. Cast fittings (lined
by injection moulding) are vented at the injection
boss. In addition these vent holes serve as weep holes in
the event the liner is damaged. Vent
hole extensions are necessary in the event pipes and fittings
are required to be insulated or if the emission of vented
materials are to be kept away from the flange bolts.
10.
All linings shall fit snugly into the pipe and fitting housings.
Any bulges in lining or indication of poor contact with the
housing shall be a cause for rejection.
11.
Plastic pipe liner shall be locked into the pipe housing using
the THERMOLOK PROCESS to provide the dimensional stability
which would be necessary as the pipe would have to withstand
the thermal cyclic conditions and also to provide maximum
vacuum resistance at elevated temperatures.
12.
The gasket seating surface of the lining shall be free of
surface defects that would impair sealing effectiveness, scratches,
dents, nicks or tool marks on the seating surface shall not
be deeper than 10% of the face thickness.
13.
Minimum liner thickness on the flare face shall be 80% of
minimum liner wall thickness.
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