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Monday, December 15, 2014

Heat Shrink Sleeves on Water Pipe

Water Pipe and Shrink Sleeves

     Are heat shrink sleeves ever used on water pipelines?  Absolutely!  Water lines (ie: pipelines that are being constructed to carry water....) are built just as often as oil and gas lines in the USA.  Ranging in diameter from 12" up to 156", shrink sleeves are used regularly in that industry.

     Generally coated in a factory with tapes, urethanes, epoxies, Pritec, polyurethanes or coal tar enamels, water lines are going to have a field joint or a girth weld just like natural gas and oil lines do.  In the field, during pipeline construction, there is going to be a bare section of pipe right at the weld after the weld has been made.  This bare area is going to have to be coated!  You can't simply bury an uncoated pipeline!

     Shrink sleeves are used regularly here.  With decades of experience and use history in that marketplace, you really can't make a more reliable, safer choice.  Also, shrink sleeves are generally fully compatible with all of the commonly used factory applied coatings listed above.  Historically, products like WPCT or WPC100M have been used extensively there.  Now, a product like the Covalence Waterwrap is a leader.

     Waterwrap is a 2 layer field joint coating system designed for corrosion protection of buried large diameter water pipelines operating at ambient temperature.  The first layer of the WaterWrap is a visco elastic, low preheat adhesive sealant.  The second layer is a thick walled, radiation crosslinked, high density polyethylene with the permanent change indicator built into the backing.

     WaterWrap is a wrap around heat shrinkable, ready fit assembly for the corrosion protection of field girth weld joints in water distribution and transmission systems.  WaterWrap/B is compatible with standard pipe coatings WaterWrap can also be used for coating bare, replacement sections of pipe and large radius bends.  WaterWrap system-B is designed to be applied with a minimum preheat temperature and is ideal for large diameter pipe.  The installation is carried out directly on the cleaned and dried (pre-heated) pipe surface.  The use of the 939 filler is required when the step down on the weld bead is greater than or equal to 1/4".  The filler 939 is a thick mastic-like butyl rubber designed to fill and smooth transition areas.  The semi-tacky composition remains flexible and easily molded in place to conform around irregular shapes.  During installation, the heat shrinkable sleeve is wrapped around the pipe and heat is applied.  The heat activated backing contracts to form a tight fit around the joint eliminating entrapped air and filling the smallest of crevices with a high quality, corrosion inhibiting visco elastic adhesive sealant.  The permanently cross linked polyolefin outer layer forms a tough barrier against mechanical damage and moisture. 

     Water wrap contains no ashpalt - does not give off gas toxic vapors.  It is safe to use.
     Water wrap offers to permanent change indicators:  underheat indicator ensures correct application heat to entire sleeve.  Overheat indicator ensures no excess heat.  Result - reliable installation and full inspectability at any time after installation.
     High modulus of elasticity backing - greater soil stress resistance and better overall performance. 
     High impact resistance - WaterWrap is tough, but flexible throughout. 
     High shrink force - optimizes flow and fill of visco elastic adhesive sealant which offers greater long term protection.
     Low application preheat makes installation fast and easy.  Keeps installation cost low.
     No special equipment or skills required - Waterwrap is easy to install and saves time.

Thursday, December 11, 2014

WPCT Shrink Sleeves

WPCT Wraparound Shrink Sleeves

     The original heat shrinkable sleeves designed to be used as corrosion prevention products on girth welds of pipelines were all manufactured as tubular products.  This mean the tubes had to be slipped into place before the pipe was welded up.  This also meant the tube had to slide far enough away from the welding area that the shrink sleeve wouldn't be damaged by weld splatter or excessive heat. 

     It was years until a wrap around shrink sleeve was developed.  What was the main problem?  How do you hold the sleeve in the 'shape' of a tube during the installation process and keep it in 'installed tube form' for the life of the pipeline?  The answer was to develop a closure strip which would do just that.

     Anyway, the WPCT wraparound shrink sleeve is an ancestor of those early, very first heat shrinkable wrap around sleeves.  There have been many improvements along the way.  WPCT right now stands for Wraparound Pipe Coating (with Thermal indicator).  (For a thorough explanation of what a thermal indicator is -- click).

     In its current form - WPCT is a product that is designed to be used on pipelines that will be buried or subea...AND will operate at or below 40C (~104F).  WPCT shrink sleeves can be manufactured for essentially any pipe size from 2.375" on up to 144" OD pipe or larger.  As a standard, WPCT is available in 11", 17", 24" and 34" widths and custom widths are available by request.

     Installation of the WPCT shrink sleeves is very simple.  After the weld is completed, the field joint area is cleaned with a power wire brush (or better).  The area that will be in contact with the WPCT sleeve (steel and adjacent pipeline coating) is then heated with a propane torch to at least 140F (often referred to as "hand hot").  The installer will then remove the release paper (exposing the aggressive, stick mastic) and wrap the WPCT shrink sleeve around the pipe snugly (no reason to leave a huge bag of slack in it).  This will result in the shrink sleeve overlapping onto itself.

     If you've purchased this WPCT material from us, you have a /UNI sleeve which means the closure strip has already been attached to one side of the sleeve.  This closure strip will go on the outside.  Heat that closure strip so that it bonds to the backing of the shrink sleeve forming a smooth tube.  Heat the closure with a propane torch so that the interior fabric reinforcement of the closure strip is able to begin showing (forming somewhat of a cross hatch pattern).  Once that is complete you are cleared to begin shrinking the sleeve (which ironically goes from a cross hatched pattern to a smooth surface). 

Monday, December 8, 2014

Wholesale Pipe Coating Sales

Wholesale Pipeline Coating Sales

     "Do you sell to _____?"  That is a pretty common question.  Just a few examples of what the blank is filled in with:  Do you sell to Contractors?  Do you sell direct?  Do you sell to end users?  Do you sell to resellers?  Do you sell to EPC companies?  Yes, Yes, Yes, Yes, Yes.  In some cases though, the more accurate question might be: "Do you sell to resellers who are selling to resellers who are selling to resellers who are selling to contractors?"  It seems a little bit sad - but yes - we do that too.  We sell pipeline coatings to all kinds of companies in all kinds of different configurations.  If you're looking for a place who keeps a large stock of pipeline coatings and is willing to sell to resellers; you've found the right folks. 

     Here at Joint Specialists, we understand that the field joint coatings for a pipeline are very often the very last detail in the purchasing chain.  I can't even tell you how often I've heard from someone in the field sharing that they already welded up pipe before they realized they didn't have anything to coat that weld with yet!  We get it.  You're building a multi million dollar pipeline.  You've had dozens of skilled employees out there assembling this pipeline.  You have thousands of dollars of equipment on the right of way in good working order.  Every decision that has been made so far involved numbers with at least a few zeros behind their price tag.  It is easy for us to see why that  $6.00 per field joint item wasn't at the top of your acquisition list. 

     But now that pipe is welded, you gotta have something immediately!  You need something overnighted!  You need something you can send a truck to pick up right now!  We understand urgency, and whether it was your fault or not that those shrink sleeves were never ordered doesn't matter to us.  We keep a large stock here and ready to go at a moments notice.  Calm down.  Take a deep breath.  We've got you taken care of.