Pipeline News Round Up 6/29/13

Pipeline News Round Up 6/29/13

News of the Week

- Pipeline Corrosion problems caused by bad CP design.  Not enough coverage.  Not enough test stations.  Not enough contact with pipe.  No mention of where the coating failure was, but they do mention that 5 “dents” were found which would certainly lead me to believe there was some kind of major trauma inflicted here (during construction, from nearby construction after the line was in service, or something like that).  (read more here)

- Enbridge pipeline shutdowns cost the company $952,000.00 per day!   

This does not include potential lawsuits – or clean up costs.

(read more here)

- Trading error leads to Interpipe shares dropping 35% within minutes. 

(read more here) 

- Report released that knocks down some of the Keystone Pipeline opponents arguments?

(read more here)

- PG&E uses cutting edge inspection pig to improve pipeline safety.

(read more here)

Shrink Sleeve Installation Tools

Shrink Sleeve Installation Tools

Question:  What tools are required for Covalence heat shrink sleeve installation?

Answer:  Ignoring the need to clean the pipe, Covalence heat shrink sleeves do not require

any special tools during installation.  Here is what is needed:

- A means of measuring preheat temperature.  This could range from something as 

sophisticated as a pyrometer with roller probe; to something

as simple as a temp stick.  

An example of temp sticks for different temperatures

 - A broad flamed torch (Covalence shrink sleeves cannot be shrunk

using an acetylene torch or a welding torch).  Our torches are sold as a kit

which includes a torch with a pilot lights; a regulator with a pressure guage

and a thirty foot long hose. 

A JS-2601 Torch Kit - available at JSI

- A long handled silicone roller.  This is used after installation to roll the overlap area

and can be used in the event that any air has become trapped (which could be

caused by poor application).  

A long handled roller; used during heat shrink sleeve installation

(Keep in mind that the contractor or end user will need to supply their own propane tanks for installation) 

Heat Shrink Sleeves: Most Dangerous Installation Error

  Question:  What is the most dangerous installation error when installing a heat shrinkable sleeve?

  Answer:  I'm going to overlook things like 'failing to clean the pipe' and 'failing to preheat the pipe'.  The most dangerous installation error is an installer who simply fails to care for the bottom of the pipe.

  Pipeline spreads are often NOT pretty.

A fairly typical (maybe even a 'good' pipeline spread.

 As you can see, there just isn't very much room underneath the pipe.  But still, the bottom half of the pipeline must still be cleaned and preheated.  In addition, the bottom of the sleeve must be shrunk and shrunk appropriately!  This same potential problem exists for any coating of course; working a liquid epoxy to prevent icicles can be even more challenging.

In any case, anytime an inspector asks me "what should I be looking for" one of the first things out of my mouth is that he's almost certainly going to need to get his knees dirty as he'll be crouching down under that pipeline to make sure the sleeve has been properly shrunk on the bottom of the pipe (and he/she needs to be familiar with this page!)

 

Installing Shrink Sleeves: How Important Is Pre-Heat?

     Another common question:  How Important is Pre-Heat?

     Short answer:  ABSOLUTELY CRUCIAL

     Long answer:  When installing a heat shrinkable sleeve as a field joint coating, you are doing so for one reason and one reason only.  You are protecting that field joint (girth weld) from corrosion.  Of course, the idea is, that if you can seal that field joint in a way that prevents water and oxygen from reaching the bare steel; then it will be impossible for corrosion to occur.


     We do this by installing a heat shrinkable sleeve that is coated with a sealant or adhesive of some kind.  If we can install that sleeve so that we get the best possible bond between sealant and bare steel (and factory applied coating) then we begin the life of that field joint from the very best possible position:  properly coated and protected.

     Of course the first step of installation is making sure we've achieved the proper cleanliness standard on the bare steel.  Different adhesives will have different requirements there and I won't discuss them here (but I did touch on surface prep for WPCT here).  The next step however is preheating the steel (and adjacent factory applied line coating) to the proper temperature.  Why is this necessary?

     Any hot melt adhesive or mastic coated shrink sleeve will have an optimum temperature at which the adhesive bonds to the substrate.  When we look at it very closely, we must create an environment where the bond-line reaches a temperature sufficient for ideal bonding.  The bond-line is that area where the hot melt adhesive of the mastic come into contact with the substrate (pipeline).  That interface is critical.

      Even though there is a significant amount of heat put into a heat shrink sleeve during the installation process; when you consider the heat insulation properties of the heat shrink sleeve and when you consider that the steel pipe will act as a heat sink (carrying temperature away from the girth weld as it acts to spread any elevated temperature through the steel in the immediate area) it isn't possible to actually achieve the necessary bond-line temperature exclusively using heat from the sleeve shrinking itself.

     As a result, the steel must be preheated.  This assures that the bond line temperature is met and that the adhesive/steel interface will be properly prepared for the bond to occur.  All Covalence heat shrink sleeves will be supplied with an installation sheet in each box.  No matter the product; there will be a 'minimum recommended preheat temperature' listed on that installation sheet.  It will certainly cause no problem to heat higher than that; with two exceptions.

- When installing a shrink sleeve system that utilizes a liquid epoxy (DIRAX, HTLP60, HTLP80, etc) it is important to keep the preheat temperature down below 200F.  Installing S1301M epoxy on a pipe that is heated above 200F will result in some smoke - and result in the epoxy more or less flash curing (which we want to avoid since we want the epoxy chemically bonding with the sleeve adhesive; and that can't happen in the epoxy cures "early")

- Most all shrink sleeves (all PE shrink sleeves anyway) shrink at ~267F.  We would not want to preheat (most of the time) to a higher temperature than that, as it could result in the sleeve shrinking before the installer is ready (as an example, before the closure has been secured). 

Heat Shrink Sleeves #1 Field Problem

Q:  What is the most common complaint that comes from a contractor installing Covalence heat shrink sleeves in the field? 

A:  There is no question - it isn't even close.  The one issue that comes up far more than any other question from the field is: "the closure isn't sticking, what do I do?" - sometimes it could be phrased "the closure is dog-earing", "the sleeve won't stick", "the sleeve keeps sticking or lifting up" - and in every case - they are talking about the same thing.  How do I know?  Because everyone and their brother - even on a pipeline crew - now has a camera phone and it is very simple for them to take two seconds out of their day to send me a picture and get real feedback on their issue. I've got my cell phone with me twenty four hours a day.

Here we see the closure strip lifting a bit from the shrink sleeve.  It wasn't heated enough during installation

     Now, let me first explain the purpose of the closure (read more here), the purpose of the closure is to hold the sleeve in the shape of a tube during the installation process.  For hot melt adhesive heat shrink sleeves (like DIRAX, HTLP60 or WPC120) the closures job is finished once that sleeve has cooled.  For mastic coated heat shrink sleeves (like WPCT, WPC65M, WPC100M, etc) the closure does need to stay attached to the pipeline for the life of the line.  So, it is important that when the above occurs....you fix it.  It only takes 10-15 seconds (possibly less). 

     Here is how to fix it:

Re-heating a closure that lifted up after installation

      Step one:  Make sure that the adhesive layer of the shrink sleeve (read here if you're not sure which side of the closure is the adhesive layer) has not gotten dirty, muddy, dusty, etc.  If necessary, wipe it with a rag and some mineral spirits.

     Step two: fire up your torch and lightly heat the closure strip where it has lifted off of the heat shrinkable sleeve. 

     Step three:  Lightly pat the closure back into place with a gloved hand.  You should heat the closure strip until you see the pattern of the fiber reinforcement showing through. 

Voila - this "major field problem" has been solved in less than 15 seconds.

 

Weekly Pipeline News Round Up

•      Enbridge 450 mile pipeline built in 1949, this particular section in Oologah Lake (Oklahoma) being inspected as repairs are expected to be needed.  Apparently this is particularly sensitive as this lake supplies many in the area with their drinking water.  Last year during routine testing, a single 40 foot section of pipe was determined to have an ‘anomoly’.  I find this remarkable.  This pipeline is 64 years old.  No indication is given in the article what the factory applied or field joint coating is (but being 64 years old; it is almost certainly nothing that is currently being used) and there is concern about one specific segment of pipe.  My guess (I stress “GUESS”) would be that such a thing must be a result of physical damage – an anchor – a some kind of debris dropped on it  - something like that.  In any case – I wish they’d publicize what the coatings are since 64 years and 1 problem (almost certainly caused by an outside source) is a pretty remarkable track record!  (read more)

•       Another Canadian Gas Line rupture??  What in the world is going on up there? (early reports are that this was likely caused by catastrophic flooding.  (read more)
  

•       Constitution Pipeline files FERC.  196km, 30” pipeline to be in service by 2015 in the NE USA.  (read more)

•       Major Pipeline explosion in Louisiana.  Early reports say it is part of the Florida Gas Transmission line.  No injuries were reported.  No explanation in the articles I’ve read about a possible cause….(read more)

•       Au Canada.  Third spill in three weeks (Plains this time).  6” line; no explanation of how/why.  (read more)

Heat Shrink Sleeve Distributor

    

655 Trade Center Parkway, Conroe, TX 77385

     Joint Specialists is a Master Distributor for Covalence (formerly Raychem) heat shrinkable products.  We are also an Elite Distributor for Raychem heat shrinkable products (part of Tyco Electronics).  With a 20,000 square foot warehouse we are able to meet customer demands more most projects.  In addition, we ship most of our orders same day.

     I could not even tell you how many times a customer has contacted us saying "I've been searching for these heat shrink sleeves for days!  Thank goodness I finally found someone who knows what they're talking about!"  We've been doing this a long time.  Buying the correct shrink sleeves for your application (and to meet the specification you are working from) doesn't have to be a difficult, frustrating process.  We can make it painless.  Give us a call.

    

A listing of just a few of the products that we keep stocked and ready to go:

WPCT shrink sleeves

DIRAX shrink sleeves

WPC100M shrink sleeves

HTLP60 shrink sleeves

TPS shrink tubes

WPC120 shrink sleeves

Flexclad shrink tape

CPSM shrink tubing

Caseal shrink sleeves

Flangeseal shrink sleeves

...and many others.

WPCT Surface Preparation

Question:  When installing WPCT shrink sleeves, how clean does the pipe have to be?

Answer:  We are always looking to get the recommended surface cleanliness ST 2 1/2 - 3.

     Sometimes this question is posed a little bit differently.  I recently had an email exchange where I was shown some photos of pipe that has been in a yard for some period of time (months).  The question was posed:  can I get these field joints to ST 2 1/2 with a wire brush after welding has been completed?

Surface corrosion from sitting unprotected for a few months.  In addition, there has been some FBE 'lifting'.

Another view of the surface rust on this pipe that has been sitting in a yard for a few months.

     Of course, it is impossible for me to tell, based on photos, how deep this rust goes and how clean the surface will be once a power wire brush has run over it; but I think this will probably still be 'ok'.  The final determination will (of course) have to be made once an effort has been made to clean it (even running the brush over it right there in the yard would be telling). 

     If a quick power brush does not get the pipe clean; the contractor will have a couple of options.  They can put in a little bit more labor with the wire brush to get the desired cleanliness or they could skip the wire brush altogether and simply sand blast the surface clean (post weld of course). 

     But to sum up; when you're dealing with a product like Covalence's WPCT which utilizes an incredibly aggressive mastic sealant, the fact that this pipe has sat for a few months probably won't mean a darn thing.

DIRAX Shrink Sleeves Use History

     I'm often asked about the reliability of our DIRAX product.  If you need a quick refresher on the DIRAX shrink sleeve; check out one of these entries:  here, here, or here.

     DIRAX has been used on pipe that will be involved in a road bore or directional drill for many years.  I've seen it used (and tested) on pipe ranging from 2" OD to 48" OD.  In addition, it has been used often as a field joint coating for non-road bore pipe when someone has a particularly harsh soil environment; or when an end user just doesn't want to take any chances and wants the best possible coating.  In cases like that, it is actually called ROCS (rather than DIRAX) and that can cause some confusion.

     In any case, looking at ~our last 6 years; I was curious how many DIRAX sleeves we've sold.  The answer actually surprised me.  In that period, we sold more than 75,000 DIRAX sleeves.  That is approximately 575 miles worth of pipe.  To put that into perspective; that would be:

A single road bore starting in Cincinnati, OH and ending in New York City, NY.

It would also be the length of a road bore starting in Rome and ending in Frankfurt!

     That would be one heck of a road bore!  Now, over the course of these years; with more than 75,000 DIRAX kits installed on more than 75,000 field joints; how many problems have there been? 

     I have been with Joint Specialists for 13 years.  I have been involved with the DIRAX product on a daily basis.  In 13 years:

- Number of DIRAX failures I am aware of:  ZERO

- Number of Corrosion problems underneath a DIRAX shrink sleeve I've heard about:  ZERO

- Number of DIRAX sleeves that were displaced during road bores:  ZERO

- Number of DIRAX sleeves that were displaced during a directional drill:  ZERO

     If you're keeping score at home; that is zero failures in more than 75,000 installs; spaced out over a 7 year period.  In case you're looking for a loophole; every single DIRAX sleeve that we sell is sold in a box with our company name and company telephone number on it.  If DIRAX sleeves were failing; we would be hearing about it.  The simple fact is; we have not heard a peep.

     The pipe beneath a road or a river is often the most sensitive part of a pipeline.  In many cases, that pipe will never been seen again.  Why aren't you choosing to install the only road bore product on the market with a perfect record??  Call us today and we'd be happy to set up a DIRAX demonstration.  Have an upcoming bore?  Let us come install a DIRAX sleeve on the front end of it; so you can see for yourself how well the DIRAX thrives.  Once you see it; you won't trust your pipe to anything else.

Wrap Around Shrink Sleeve

Wrap Around Shrink Sleeve

     A wrap around shrink sleeve is one of two heat shrink sleeve configurations that are available (the other being a tubular sleeve).  A wrap around generally has two components; the sleeve material itself and the closure strip.  To make matters much more complicated than they truly need to be; each component (sleeve and closure) is a multi-layer material.  I'll break each down below.

     First we will look at the shrink sleeve itself.  In this particular case we are looking at the WPCT product, currently manufactured by Covalence Heat Shrinkable Products, underneath the Seal for Life umbrella of corrosion prevention products (WPCT was originally created under the Raychem name).  WPCT is a two layer shrink sleeve, with the outer layer being a radiation crosslinked, high density polyolefin and the inner layer consisting of a mastic sealant (WPCT is supplied with a release paper, but I am ignoring it for the sake of this discussion because it will be discarded during installation).

Here we see the WPCT backing.  Notice the dimples which will fade away as this product is properly installed

Here we see that once the release paper is peeled back, the stick mastic material is exposed.

     You can't tell from the photo (of course) but the WPCT is coated with an extremely aggressive mastic sealant.  In the Texas summer, this material will stick aggressively to anything it touches.  The beautiful thing is that it retains that same aggressive nature for many years (we know because we have seen pipelines with this product installed many decades after their original installation.

     Next we will take a closer look at the closure strip (internal name 'WPCPIV').  It is typically supplied in the same standard widths as the shrink sleeves are and is available in 3", 4" and 6" widths.  Selecting a width depends primarily on sleeve material type; pipe OD, etc.  The WPCPIV is technically a three layer product; incorporating a radiation crosslinked, HDPE backing; a fiber mesh to give the closure superior integrity and a high shear hot melt adhesive to make sure there is no slipping that occurs during installation (if slipping were to occur, the shrink sleeve might begin to work its way off of the pipe during installation).  

The closure backing.  This is the side which will be visible after complete sleeve installation.

This is the high shear adhesive side (with the fiber mesh visible through it).

     In the picture immediately above this sentence; that checkered pattern is the fiber mesh of the closure and also the side of the closure strip that will no longer be seen once the shrink sleeve is installed (it will be fully pressed and bonded to the PE backing of the shrink sleeve).  

     In our shop, we don't ever sell the closures and shrink sleeves separately; they are always attached to one another to make life easier on the contractors.  The truth is that it makes life easier on us as well as we experience dramatically fewer calls for field service, missing components or field problems.  

     There you have it; all you ever wanted to know about wrap around shrink sleeves!

Pipeline News Summary - June 2013

 Pipeline News

A summary of some of the stories that caught the attention of journalists this week:

• Russia hits Chinese pipe manufacturers with a 19.5% tariff to battle pipe dumping and price erosion (read more).

• The FREEDOM Pipeline is no more as Kinder Morgan pulls the plug on this proposed 2 billion dollar project.  Customers preferred the rail system over pipelines to transport oil (read more).

• Piedmont completes its $500 million, 128 miles pipeline after two years of work (read more). 

• For the second time in two months; Ecuador (PetroEcuador) loses a pipeline to avalanche (read more).

•  Man sentenced to 22 years for trying to blow up an Atmos Energy pipeline in Dallas, TX with a homemade explosive device (read more).

• Board determines that 2012 pipeline explosion in British Colombia last year was not caused by corrosion or external damage - but was instead caused by a pre-existing flaw in the pipe (read more).

• BC government unwilling to approve Enbridge Northern Gateway Project...yet (read more).

•  

Benefits of Cross Linking

What is the benefit of crosslinking a polyethylene?

 Shape memory!  

Crosslinking gives a heat shrink sleeve a memory (and a desire) to return to its original shape.  This is how a 2" tube shrinks to a 1"; how a 30" sheet shrinks to a 22" or how a molded part shrinks to its original shape (read more about crosslinking here).  In the pipeline coatings world or the electrical splicing world; without shape memory; we would not have a product to sell.

 Abrasion resistance.  

Crosslinking makes the PE (or polyolefin) backing tougher and more abrasion resistant.  This is important for buried and subsea pipelines; for high voltage wire insulation and for splicing.  In addition, because the PE is more abrasion resistant; a thinner PE jacket can sometimes be used which translates to dramatically less weight on airplanes, automobiles, etc.   

Better performance at higher temperatures.  

Since the PE no longer melts, it isn't subject to dramatic weakening at higher temperatures (within reason, of course).  

Improved chemical resistance.  

The crosslinked PE is less susceptible to different chemicals and solvents. 

Reduction in gas permeation.  

In corrosion prevention, reducing the water vapor transmission is VERY important.

Improved mechanical properties. 

Properties like tensile strength, penetration resistance, hot water immersion and others. 

Closures: Must I use them when Installing Shrink Sleeves?

     I'm often asked, "Do I have to use these closures?  Can I install this shrink sleeve without it?"  You see, not every manufacturer out there sells /UNI sleeves (where the closure is pre-attached to the sleeve as explained here).  Often times, someone gets a big box of shrink sleeves and the closure strips come in a separate box.  Other times, the closure strips are all buried at the bottom of the box which can make it difficult to get to them.  Sometimes, all of the closures get dropped in a mud puddle and are essentially ruined!
 

Please only expose your shrink sleeves to an environment like this AFTER installation!

      Since every single sleeve we at Joint Specialists sell goes out as a /UNI sleeve, we don't get this question too often, but it is always shocking how often we get phone calls asking for technical support about our competitors products!

     In any case, the answer is YES.  Every wrap around shrink sleeve MUST have a closure strip to be properly installed.  Without the closure strip, the sleeve will simply fall to the ground during installation making a rather large mess.  The closure strip holds the sleeve in the shape of a tube (pressed to the pipe) during installation.  After the sleeve has cooled, the closure strip has essentially served its purpose (but we always recommend you go ahead and leave it in place anyway!). 

     There are tubular products that do not require a closure.  A few examples of those would be TPS, WCSM, MWTM and CPSM (there are others).  Don't get yourself into a position where you're having to call me with this question.  Make sure you're buying /UNI sleeves and it will never come up!

Radiation Crosslinking vs Chemical Crosslinking

     As more and more heat shrink manufacturers come into being in East Asia and in Eastern Europe, a question that comes up often is:  Is there really a difference between Radiation and Chemical Crosslinking?

     To that, I must shout a resounding YES!!  Here in our own shop, we've often gotten to play with chemically crosslinked products that were sent to us by foreign companies attempting to gain a foothold in the USA.  These products have always been markedly inferior to our own Covalence / Raychem products.  We've seen products that don't even return to their original shape (memory loss or inferior crosslinking), we've seen products with backing material that can actually be torn using only your fingers (low density polyethylene compound backing).  We've also seen products that; after sitting on our samples shelf collecting dust for a year or two; completely fall apart during installation (limited storage life). 

     One of the primary differences between these eastern European and eastern Asia heat shrink manufacturers is that they primarily utilize a chemical cross linking process to manufacture their heat shrinkable sleeves.  I came across an incredibly informative paper written by a Dr. Lewis A. Parks (here).  He (with much more knowledge and education about cross linking than I will ever have!) discusses in detail the difference between these two crosslinking techniques.  I will touch only on a few of the advantages and disadvantages he lists.  If you're looking for more in depth reading on this subject; please go read his entire paper!

Advantages of Radiation Crosslinking

1. Many different types of compounds can be radiation crosslinked.  On the Covalence side, we've seen this with many different polyolefins and even some polypropylenes.  On the Raychem heat shrink side they do also focus on polyolefins, but they've also ventured into silicone rubbers, teflon, PVC, viton and other materials.
2. Many different types of compounds can be radiation crosslinked.  On the Covalence side, we've seen this with many different polyolefins and even some polypropylenes.  On the Raychem heat shrink side
3. Reliability.  Raychem Corporation began producing heat shrinkable technologies in the early 1970's. While that might make heat shrinkable sleeves sound like an ancient technology; the truth is that it means we've got 40+ years of proven, successful, reliable use history.  This really is an amazing fact that is often overlooked.  Since Covalence was originally part of Raychem Corp as the pipeline division (and Ultra-Tec), it also carries that incredible use history, even though the product name has changed.
4. Radiation crosslinking is an efficient use of energy.  This is more and more important every year it seems.
5. The process is cleaner, with the potential for no unwanted 'residuals' in the product. 

Disadvantages of Radiation Crosslinking

1. The process of radiation crosslinking are not widely understood (that makes companies like Raychem and Covalence even more valuable due to their experience with this process).
2. High capital cost.  It is expensive to purchase a large electron beam.  No real surprise there, to make a high quality product requires a fairly significant investment.  It requires years of commitment to learning the ins and outs of a technology.  It requires more than setting up a simple 'back yard crosslinking operation.'

 Advantages of Chemical Crosslinking  

1. Low investment for set up.  Getting set up to perform chemical crosslinking is cheap and easy.
2. It is a technique that is fairly easy to understand.
3.  Can easily be done in small batches

Disadvantages of Chemical Crosslinking 

1. More limited options in terms of compounds to work with
2. Requires a relatively complicated compound design
3. Compounds have a limited storage life
4. Crosslinking is sensitive and can be difficult to control
5. Potential for undesirable 'residuals' in the product
6. High energy consumption

     So, the next time you're considering using a chemically crosslinked shrink sleeve, consider the fact that you're likely sacrificing significantly on performance.  The quote you've got probably looks pretty attractive.  You may see this as an opportunity to save a lot of money on your project.  Unfortunately, any money saved on the front end is likely to come back to haunt you 20 fold when you discover major corrosion problems 6 months, 12 months or 24 months down the road.  

Liquid Epoxy Specifications

What is wrong with this picture?

     One of the potential hazards of installing a liquid epoxy as a field joint coating is that it can be difficult to control the thickness of the coating.  Some epoxies go on thicker than others (in a single coat).  Some installers can install thicker than others.  Weather conditions (heat) can affect the thickness of the coating.

     There are a lot of things that can go wrong, which is why it is imperative that the project specification dictates a minimum field joint coating thickness for liquid epoxy coated joints.  In the above photo, this field joint is coated with a liquid epoxy that isn't even as thick as the factory applied FBE (the evidence is that the FBE step down is so highly visible).  If this pipeline gets buried like this, it won't even last a month in the ground (not to mention the fact that it probably wouldn't even survive holiday detection).  In addition, the weld bead is still has some spots where air bubbles prevented a homogenous coating.

     Since this pipeline is near my home, I am sure hoping that they came back in and put several more layers on this field joint.  I'm also hoping that the end user specified a minimum thickness - and that the contractor and inspector are vigilant in their efforts to make sure this line isn't buried until every inch of its coating has been inspected.  Like most coatings; liquid epoxies certainly have their place, but only if the installers and inspectors are taking their jobs as seriously as they need to.

DIRAX Kit - Explained

     Question:  What is included in a DIRAX kit?

     Answer:  This is one of the most commonly asked questions.  Given the fact that ordering a WPCT sleeve is very simple and straightforward - I completely understand why the DIRAX Kit is harder to understand.

A DIRAX kit includes three components as seen below:

A DIRAX Sleeve

     This (above) is the DIRAX shrink sleeve.  It is (as discussed elsewhere in this blog) a fiber reinforced, high shear shrink sleeve specifically designed to withstand the tremendous forces that a pipe coating experiences during a road bore (or directional drilling) application.  As standards, it is available in widths of 12", 17" and 24" (the sleeve in the picture is a 12" wide sleeve).

Leader Strip or Wear Cone

     This (above) is the Wear Cone or Leader Strip.  It is a 3" wide shrink sleeve; made from the same exact material as the DIRAX sleeve.  It is installed on the leading edge of the sleeve to give it added protection.  

An S1301M Epoxy Primer Kit

     This (above) is an S1301M Primer 15 Kit.  It includes the "A" component; the "B" component; an applicator pad; two gloves and a mixing stick.  This acts as the primary corrosion coating for DIRAX shrink sleeves.  One thing that can be confusing to new customers is that one epoxy kit (as pictured) contains enough epoxy for more than one field joint (most of the time) depending on the outside diameter of the pipe and the width of the sleeve (since epoxy is applied everywhere the sleeve will contact the pipe on FBE and ARO coated pipe).  

Below is the ratio of Epoxy Primer Kits to Shrink Sleeve dependent on sleeve and pipe sizes.  Where it says 5:1; this means 5 DIRAX road bore kits can be installed using 1 epoxy kit (assuming the contractor has properly welded, and cleaned those 5 joints ahead of time).  It also means 1 epoxy kit will be supplied; as part of the kit; for every 5 DIRAX sleeve kits purchased.

DIRAX Epoxy Supplied Chart

DIRAX 2375-12 - 5:1

DIRAX 2375-17 - 5:1

DIRAX 2375-24 - 5:1

DIRAX 2875-12 - 5:1

DIRAX 2875-17 - 5:1

DIRAX 2875-24 - 5:1

DIRAX 3500-12 - 5:1

DIRAX 3500-17 - 5:1

DIRAX 3500-24 - 5:1

DIRAX 4500-12 - 5:1

DIRAX 4500-17 - 5:1

DIRAX 4500-24 - 4:1

DIRAX 6625-12 - 5:1

DIRAX 6625-17 - 4:1

DIRAX 6625-24 - 3:1

DIRAX 8625-12 - 5:1

DIRAX 8625-17 - 3:1

DIRAX 8625-24 - 2:1

DIRAX 10750-12 - 4:1

DIRAX 10750-17 - 3:1

DIRAX 10750-24 - 2:1

DIRAX 12750-12 - 3:1

DIRAX 12750-17 - 2:1

DIRAX 12750-24 - 2:1

DIRAX 14000-12 - 3:1
DIRAX 14000-17 - 2:1
DIRAX 14000-24 - 3:2

DIRAX 16000-12 - 3:1
DIRAX 16000-17 - 2:1
DIRAX 16000-24 - 3:2

DIRAX 18000-12 - 3:1
DIRAX 18000-17 - 2:1
DIRAX 18000-24 - 3:2

DIRAX 20000-12 - 2:1
DIRAX 20000-17 - 3:2
DIRAX 20000-24 - 1:1

DIRAX 22000-12 - 2:1

DIRAX 22000-12 - 3:2

DIRAX 22000-12 - 1:1

DIRAX 24000-12 - 2:1
DIRAX 24000-17 - 3:2
DIRAX 24000-24 - 1:1

DIRAX 26000-12 - 2:1
DIRAX 26000-17 - 3:2
DIRAX 26000-24 - 1:1

DIRAX 28000-12 - 3:2
DIRAX 28000-17 - 1:1
DIRAX 28000-24 - 1:1

DIRAX 30000-12 - 3:2
DIRAX 30000-17 - 1:1
DIRAX 30000-24 - 2:3

DIRAX 32000-12 - 3:2
DIRAX 32000-17 - 1:1
DIRAX 32000-24 - 2:3

DIRAX 34000-12 - 3:2
DIRAX 34000-17 - 1:1
DIRAX 34000-24 - 2:3

DIRAX 36000-12 - 3:2
DIRAX 36000-17 - 1:1
DIRAX 36000-24 - 2:3

 

DIRAX 38000-12 - 3:2
DIRAX 38000-17 - 1:1
DIRAX 38000-24 - 2:3

 

DIRAX 40000-12 - 1:1
DIRAX 40000-17 - 1:1
DIRAX 40000-24 - 1:2

 

DIRAX 42000-12 - 1:1
DIRAX 42000-17 - 3:2
DIRAX 42000-24 - 1:2

 

DIRAX 44000-12 - 1:1
DIRAX 44000-17 - 2:3
DIRAX 44000-24 - 1:2

 

DIRAX 46000-12 - 1:1
DIRAX 46000-17 - 2:3
DIRAX 46000-24 - 1:2

 

DIRAX 48000-12 - 1:1
DIRAX 48000-17 - 2:3
DIRAX 48000-24 - 1:2

 

How Many Field Joints in a Mile?

Question:  How many field joints are in a mile?

or

Question:  How do I know how many shrink sleeves I'm going to need for my project?

Answer:  They don't get very much simpler than this!  In our world; pipe is almost always sold in lengths very close to 40 feet.  Based on that, all we need is a calculator, pen and paper, or my favorite - and abacus to figure it out.

So, you've got 5 miles of pipe.

1 mile equals 5,280 feet.

Every 40 feet is a field joint.

You will have 132 field joints per mile of pipe.

5 x 132 = 660 sleeves will be needed

(this does not include any overage allowance).

Or, you've got a 1200 foot directional drill.

1200 / 40 = 30 DIRAX sleeves will be needed.

Or, you've got 57 miles of 24" pipe

57 x 132 = 7,524 sleeves will be needed.

Simple!

Shrink Sleeves for Pipeline Field Joint Coatings

     In the world of heat shrink, there are a couple of different product lines that call themselves "shrink sleeves."  The one that seems to always be at the top of Google when searching for 'shrink sleeves' is the thin plastic labels that go around things like Gatorade bottles; energy drinks and chocolate milk.  When you walk through a grocery store; you probably see tens of thousands of these covering all of your favorite products. 

      It is also easy to find shrink sleeves designed to replace (or increase the size of) the grip on a tennis racket.  It is hard to imagine this working well with a low cost shrink sleeve (this is my opinion because I've personally evaluated it in the past) but I could certainly be wrong! 

     When considering pipeline coatings however (and shrink sleeves for sealing splices, terminating electrical lines, motor connection kits, etc) the leaders in the industry are Covalence (a Seal for Life company) and Raychem (a Tyco Electronics company).  For the purpose of this article, I'll be looking exclusively at Covalence.

    

 

 

WPCT Shrink Sleeve for Pipeline Corrosion Prevention

     Covalence heat shrink sleeves are designed to offer corrosion protection (prevention) to girth welds of steel pipelines.  Any buried (or offshore) steel pipeline is going to be coated in a plant.  By far the most popular factory applied line coating in the USA is FBE (in other parts of the world; three layer polyethylene coatings are dominant).  Pipe is typically moved in 40 foot long 'joints'.  You've probably seen trucks loaded with FBE coated pipe driving down the freeway depending on what part of the country you live in.

     In any case, when a plant coats a 40 foot joint of pipe; they leave the ends of the pipe clean (with FBE, typically 2-3 inches per side are left clean).  This is because when this piece of pipe is welded to another identical piece of pipe; the welding process would damage or destroy any factory applied coating that is close to the welding area anyway, so it is best to just leave it clean. 

     This means that when a pipeline is constructed; every ~39.5 feet is an area ~12" wide of bare steel.  This bare steel must be coated somehow and that is where our product comes in.  Our shrink sleeve systems can be anything from two layer; to three layer; to ten layer.  In this case I will look at only a two layer system. 

     Of the two layers of the shrink sleeve; one layer is a heat shrinkable polyethylene backing and the other layer is an aggressive, stable mastic sealant.  To look at it in the simplest of terms; the purpose of the heat shrink backing is two fold.  First; it shrinks onto the cleaned and preheated pipe surface, causing the aggressive mastic to fill any imperfections in the steel.  In addition, the mastic forms a strong bond to the steel and adjacent factory applied coating AND keeps its strong bond to the heat shrink sleeve backing.  It essentially creates a cohesive coating designed to prevent any air or water from getting to the bare steel of the pipeline...for the life of the pipeline.

     Second, the heat shrink PE backing stays in place and offers physical protection to that mastic sealant for the life of the pipeline.  It protects during backfill; it stays in place through contraction and expansion of the pipeline and prevents other outside forces from exposing the previously bare metal of that field joint to air or water. 

     So, in a sense, if you consider the heat shrink backing of the shrink sleeve to be first; a delivery system to get the sealant in the proper place; at the proper temperature to attain a bond - and if you consider it to be, second, a physical protection of that sealant - then you'll be very much on the right path. 

Covalence Product Line Summaries

     Covalence (formerly Raychem) manufactures an entire line of products designed to be used with many, many different pipeline parameters and conditions.  Below is just a short list of some of the products available:

WPCT 

Wrap Around Pipe Coating with Thermal Indicator 

 This is our most commonly sold standard wrap around sleeve rated for use on ambient temperature lines (104F).  It has been used extensively onshore and offshore for many years. 

TPS 

Tubular Pipe Sleeve

This is essentially WPCT supplied in a tubular form.  Available for pipe sizes:

2.375", 2.875", 3.5", 4.5", 6.625", 8.625"

DIRAX 

A sleeve system designed for Directional Drilling and Road Bore applications.  The toughest sleeve ever made with a fiber sheet woven into the backing.  This sleeve utilizes Raychem’s S1301M epoxy primer.

WPC100M 

Wrap around sleeve for use on lines operating at up to 80C (176F) onshore and 

up to 100C (212F) offshore

WPC120 

Our highest temperature rated sleeve, approved for use on pipelines operaing at 120C (251F)

HTLP60 

A three layer sleeve system rated for use on lines operating at up to 60C (140F)

CS

High expansion (meaning it shrinks a lot) fiber reinforced sleeve for sealing between 

a casing pipe and a carrier pipe.  This product shrinks ~66%

FS 

High expansion, fiber reinforced sleeve for encapsulating a flange 

(with FS installed; the flange is still re-enterable)

CPSM 

A high expansion tube used for upset tubing

Flexclad 

A heat shrinkable spiral wrapped tape

S-1301M Epoxy 

Used in conjunction with DIRAX, HTLP60, HTLP80 and other product.

This is not designed to be a stand alone liquid epoxy coating.

Perp / Perp Melt Stick 

Used to repair damage to PE coatings

TWDB 

Heat shrink tape specifically for sealing duct

HTLP80 

 A three layer PE sleeve system using S1301M Epoxy as the first layer.  

 Rated to 80C (176F)

HTLP-PP 

 A product designed specifically for Polypropylene (PP) coated pipe.  Installation does require an induction coil. Rated to 120C (251F).  The backing of this product does contain PP. 

PPS120 

Utilizes the WPC120 sleeve and separate mastic rolls to coat PP coated lines operating at 120C (251F)

WPC65M 

Rated to 65C (155F)

Rayclad 

A factory applied line coating

Waterwrap 

A wrap around product designed specifically for large OD water pipe.

WPCZ

A mastic sleeve specifically designed to be used with hot mastic pours and other infill systems.

Shrink Sleeve Nomenclature Explained

WPCT 8625-11/UNI

     This ^ would be a common nomenclature for one of our most commonly sold products.  In this blog post, I'll walk you through exactly what it means and give several other examples.  

     The first set of letters (to the left of the first space) represent the MATERIAL TYPE.  Covalence has a number of different product and material types designed for a number of different pipeline conditions and parameters.  In this case, this product is our WPCT product (which is designed for pipelines that will operate at ambient temperatures).  

     The first set of numbers (to the right of the first space) represent the OUTSIDE DIAMETER of the substrate in mils; so 8625 mils is equal to 8.625 inches; a common pipe size.  We always size our sleeves by the largest substrates outside diameter in order to be sure that the sleeve is long enough to properly wrap around it.

     The second number; just after the - is the PRODUCT WIDTH (standard product widths can be found here and you can find help in determining how wide of a shrink sleeve you need here).  In this case, this WPCT sleeve for an 8" pipe is being offered in an 11" width.

     Finally, the /UNI indicates that this is a one piece sleeve; with the closure strip preattached to the shrink sleeve in our shop.  This makes installation in the field significantly easier and we've found it drastically reduces the number of field problems that arise.

    A few more examples:

DIRAX 4500-12 - this is our DIRAX sleeve designed for use on pipe that will be road bored or directionally drilled; for a 4.5" OD pipe; in a 12" width.

WPC120 16000-34/B/UNI - this is our highest rated product (temperature wise); WPC120 (rated for use on lines operating at up to 120C) made for a 16" OD pipeline; and offered in a 34" width.

CS 36000 - This is our Caseal product designed for a 36" OD casing which comes in a standard 24" width (width is not listed for this product).

TPS 6625-18 - This is our Tubular Pipe Sleeve (also called a slip on or sock type sleeve) designed for use on a 6.625" OD pipeline and this is being supplied in an 18" width.