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Wednesday, January 31, 2024

Using Shrink Sleeve Rolls or Cut Pieces

Shrink Sleeves:  Cut Pieces vs Bulk Rolls

     When estimating costs for shrink sleeves, there is one important decision to make.  Shrink sleeves can be purchased two ways:
  1. Buy bulk rolls of material (100 to 300 feet long); buy separate closure strips (WPCPIV) and a crew could cut sleeves down from the roll as needed either in the shop or in the field.
  2. Buy pre-cut shrink sleeves; which are designed for specific pipe sizes and have the closure pre-attached in the plant.  
     Which is the best solution for you?  Read below and find out.

WPC100M rolls
Here you see a roll of WPCT shrink sleeves with some closure strips (loose).

     Let me be right up front:  this is not what I recommend you do.  Yes, buying rolls of material and loose closures strips (1 per shrink sleeve you intend to cut from the rolls) has some slight appeal.  The material costs can appear to offer some advantages and most pipeline crews have plenty of labor around to cut their own sleeves.  

     There are a lot more potential problems with this route, however:
  • A shrink sleeve has an intended cut length.  That cut length is designed to create a sleeve that is long enough to wrap all the way around the field joint and overlap back onto the sleeve.  I've seen too many times when someone in the field uses cut lengths that are simply too short for the sleeve to properly be installed.  That results in a lot of wasted material and labor.
  • Installing a "two piece" shrink sleeve (where the WPCPIV closure strip is not plant-attached to the sleeve itself) leads to many more field issues when securing the closure strip than when crews install a once piece pre-cut shrink sleeve.  So many more field issues and questions.
  • Cutting shrink sleeves from a roll in the field can be challenging on its own.  You need a long, flat, clean surface to cut on (to avoid getting the sleeve overly dirty on the front end.  In addition, if the sleeve is not cut using the proper equipment; and the sleeve is cut in a way that leaves 'imperfect' or jagged cuts is very likely to split during installation.  Splitting would mean the sleeve must be removed; the field joint re-cleaned and then a new sleeve installed.  This is a difficult process as even sleeves that split because they weren't cut properly is a very difficult task.  Shrink sleeves are not designed to be removed; they are designed to say bonded to the pipe for the life of the line.
  • On the financial side; the "savings" with cutting your own sleeves may not be as large as you think.  Let's pretend for a moment that you're working with a 16" OD Line.  The proper cut length for a 16" OD shrink sleeve is 56".  Pretend you are working with a 100 foot bulk roll of shrink sleeve material.  You will be able to cut 21 shrink sleeves (that are 56" long) from that 100 foot roll.  You will be left with a piece of shrink sleeve material that is 2 feet long.  You won't be able to use a 2 foot section of shrink sleeve on your 16" line - so that is going to be thrown out. That is 2% of that roll wasted (which eats into any cost savings you thought you were getting)
     If none of that dissuades you (I could have listed several more disadvantages to trying to cut your own sleeves); these are the shrink sleeve material types that I keep in stock:
  • WPCT 11" wide
  • WPCT 17" wide
  • WPCT 24" wide
  • WPCT 34" wide
  • WPC100M 11" wide
  • WPC100M 17" wide
  • WPC100M 24" wide
  • WPC100M 34" wide
  • WPC120 11" wide
  • WPC120 17" wide
  • WPC120 24" wide
  • WPC120 34" wide
  • HTLP60 11" wide
  • HTLP60 17" wide
  • HTLP60 24" wide
  • HTLP60 34" wide
  • HTLP80 11" wide
  • HTLP80 17" wide
  • HTLP80 24" wide
  • HTLP80 34" wide
  • DIRAX 
  • ROCS

/UNI Sleeve
An example of a /UNI sleeve (1 piece, pre-cut, properly sized, closure attached)

     Buying cut piece sleeves, on the other hand, is simple.  Open the box.  Set aside the installation sheet for your crews to reference.  Grab one sleeve.  Install it.  Incredibly simple - everything is the right width, the right cut length, etc.  Much less can go wrong here.  

     So, say you want a WPC100M shrink sleeve for an 8" OD pipe and you want it in a 17" width.  You simply order:  WPC100M 8625-17/UNI.   Off you go.

The WPC100M is the material type (mastic sleeve designed to be used on pipelines that will operate at up to 176F (212F in some applications).  The 8625 is the diameter of the pipe in mils.  The 17" is the width of the sleeve (actually closer to 17.75") and the /UNI means the closure strip (WPCPIV) is already attached to the sleeve, making your installation simpler.

Have questions?  Reach out:  936/321-3333

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