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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.

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