Raychem CSEM Shrinkable Sleeve
I've seen a specification floating around the last few days calling out for our CSEM product. Covalence (formerly Raychem) has twenty or more products that are regularly specified and used here in the USA. Worldwide, that number grows (as very often different countries will have different opinions about the most important properties of a pipeline coating.
This is a specification is written only for repairing damaged
sections of FBE (not for field joint). In addition - this spec calls out
for a 'high expansion sleeve capable of coating straight line pipe
and/or couplings'.
The two products mentioned are CSEM and our competitors competitor product X:
CSEM
is called CS here in the USA (Caseal) and it is a high expansion
material, that shrinks 66% allowing it to cover a wide range of
coupling/pipe dimensions. CS more than exceeds the 100 mil
requirement.
X is a ~33% shrink material (so not
nearly as versatile and unlikely to be able to handle most coupling
configurations). In addition - X does not meet the 100 mil requirement
noted in detail by the specification.
X also does not meet the
requirement of 2.5 A which calls for the sleeve to be coated on the
inside with a visco-elastic mastic sealant.
So, this specification is a little confused because X is listed by name but does not meet 3
of the requirements. In addition, since this is an FBE repair
specification - the X will be very difficult to use when damage is
found during holiday testing after welds have been made (or when pipe
has been damaged after the pipe has already been welded).
Beyond all of that of course - is the statement that the Engineer can approve an "equal". But here are my thoughts:
-
CS (CSEM) is a great product. If they are expecting to need to coat or
repair damage to mechanical couplings, this would likely be the best
choice (we would need to know the OD of the coupling and
the OD of the pipe of course). But, if you are expecting to only do
repairs on straight line pipe -- this product would still work VERY well
-- but in my opinion it would be a little bit of overkill and more
expensive than you really 'need' to spend.
- X is a
product that was loosely based on our own TPS product. TPS is our "or
equal" that is sold regularly against and in place of X. TPS
is a tubular product, coated with a mastic sealant and is fully
compatible with FBE coated pipe for both field joints and repairs.
-
Our 'wrap around one piece' version of TPS is called WPCT. It would
also be an excellent choice, particularly in cases where the pipe has
already been welded and sliding a tube hundreds of feet down the line
simply isn't practical. Neither TPS or WPCT would meet the 100 mil
requirement, but neither does the X, so I am offering them here.
In
addition - TPS and/or WPCT would be excellent products for the field
joints and offer much stronger technical properties than a cold applied
tape does (and quite frankly; are less reliant on installer skill and less apt to provide a spiral leak path).
All
of these thoughts are based on the belief that we are talking about an
ambient temperature pipeline. If this is an elevated temperature line
than everything I have said here would need to be re-evaluated based on
whatever that temperature is.
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