Visit our website:
Call: (936) 321-3333

Thursday, February 11, 2016

Shrink Sleeve Closures

Closures - WPCPIV

     Any wrap around shrink sleeve requires a closure of some form.  What does the closure do?  It simply holds the sleeve in the shape of a tube -- in place -- around the pipe during the shrink process.  If you did not use a closure of some kind, your shrink sleeve would turn into a giant mess of PE and mastic in a pile on the ground underneath your pipeline!

     So what are closures?  First of all - we should say there are several different types.

Standard WPCPIV Closures:  These are the regular closures we use for most wrap around heat shrink sleeves.  They are thin and comprised of three layers.  Layer 1:  radiation crosslinked polyolefin backing.  Layer 2:  fiber mesh to imbue that PE with added strength.  Layer 3:  high shear adhesive designed to stick to the sleeve backing and prevent any slippage at all from occurring as the heat shrink sleeve begins to exert force on itself during the shrink process.

     Rail and Channel Closure: This is a physical closure.  One end of the sleeve has a PE toe sticking out.  This toe meets up with the toe on the opposite side - and then a stainless steel channel is slid into place to hold those toes together during the shrink process.  This method is more often used on high expansion electrical products.

     An actual Zipper:  some products like our Caseal and Flangeseal use an actual zipper; sewn into the backing; in order to hold that sleeve together during the shrink process.  A regular closure is then used -- but only to prevent the heat from the torch from adversely effecting that zipper.

     That more or less covers it.  If you are looking to buy rolls of material in order to cut the sleeves yourself - you absolutely must use closure strips as well or else you are very likely going to have some major field issues -and some major irritations in your future.

Monday, February 8, 2016


High Temp Shrink Sleeves

m100 shrink
An installed WPC100M sleeve.
     In the oil and gas coatings world, many lines are designed to have the capability to coat a pipeline that could operate at up to 100C.  In terms of factory coatings, a 100C line has a number of options:  high temp FBE, PP or PE being just a few of them.  WPC100M is compatible with any of those options.  The aggressive mastic of the WPC100M bonds well to any commonly applied pipeline coating.  In addition, the surface preparation is not nearly as stringent as many epoxies and WPC100M is a very practical field application.  Save money on surface prep and save time on labor with WPC100M.

100M benefits

WPC100M Features and Benefits:
  • Dimpled backing provides a 'permanent change' indicator for application of heat.  This ensures correct application of heat and allows easy post heat inspection.  Reliable inspectability at any time; even hours, days, weeks or months later.
  • Low preheat sensitivity and proven functionality.  Installation friendly in combination with high functional performance.
  • Available as all in one unit or roll form - saves money by keeping inventory and logistics costs low.
  • High shear resistance - WPC offers safer protection.
  • Covers a wide range of operating temperature ratings.  Offers a solution for nearly every pipeline coating application.
  • No special equipment or skills required - only a standard gas torch and a roller.  Fast, easy and low cost application.

  • WPC100M rated to 80C onshore / 100C offshore
  • Compatible with PE, PP, FBE, Tape and Coal Tar
  • 100C preheat temperature required
  • ST 2 1/2 - ST3 or SA 2 1/2 surface prep required
  • Soil Stress Restrictions:  NONE

Wednesday, February 3, 2016

Tubular Shrink Sleeves (TPS)

Heat Shrink Tubes - TPS

Shrink Tube Pipeline
An installed TPS shrink sleeve.
     Shrink sleeves for preventing corrosion on pipelines come a number of different varieties, material types and configurations.  When looking specifically at configurations, the most basic breakdown looks at wrap around shrink sleeves and tubular shrink sleeves.  For this discussion today we will be looking specifically at tubular shrink sleeves.

     Often called slip on sleeves or slide on sleeves; tubular shrink sleeves are supplied already in the shape of a tube.  As a result, they must be slipped onto the pipeline before the weld is made at the field joint.  Sometimes this is a fine and acceptable option.  Other times, the crews can sometimes forget to slide them on in advance -- and then they must rush a wrap around sleeve out to the job site to use. 

     The most basic tubular pipe sleeve that Covalence (formerly Raychem) manufactures is called TPS - that stands for Tubular Pipe Sleeve.  It is generally used only on smaller pipe sizes.  This is because of the machinery that manufactures these tubes.  TPS is available for pipe sizes 2" thru 8". 

     TPS shrink sleeves are designed to be used on pipelines that will operate at ambient temperatures.  Ambient is generally defined as 104F or less.  By "operate" we mean a consistent temperature.  TPS sleeves are generally available in two different lengths - by lengths I mean coverage along the pipe.  Those two TPS lengths are 9" and 18".  When choosing a length it is important to be aware that a shrink sleeve needs to be wide enough to coat all bare steel and overlap onto the adjacent factory applied coating by at least 2-3" per side.  It is important to verify acceptable overlap with the applicable specifications as some end users can require 4 or even 5" of overlap on either side.

Tubular shrink sleeve benefits

  • Dimpled backing of the TPS provides a permanent change indicator for application of heat.  This ensures the correct application of heat and allows easy post heat inspection (even months later).  Reliable inspectability at any time.
  • No primer required - which saves cost and installation time and labor costs.
  • Low preheat sensitivity and proven functionality allow easy application combined with high functional performance.  
  • Mechanically strong and resists abrasion, impact and penetration.  TPS is reliable, tough and user friendly.
  • Specially formulated sealant ensures a strong bond and a tight seal.  High peel and shear values after installation.
  • Sealing adhesive automatically flows and repairs minor mechanical damage - this is called the self healing effect.
  • No special equipment or skills required.