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Thursday, March 12, 2015

CSEM Shrinkable Sleeve for Repair of FBE Coating

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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