TPS and WPCT Shrink Sleeve (Covalence / Raychem)

 TPS and WPCT Shrink Sleeve 

(Covalence / Raychem)

A roll of WPCT material

     One of the very first, original shrink sleeves was an early form of TPS.  It was a tubular sleeve, bonded into the form of a tube in the plant.  It was originally offered for pipe sizes 2" through 12".  The sleeves did revolutionize the market taking business away from cold applied tapes, from coal tar joint applications and from granny ragging the field joints.  Suddenly with TPS on the market, field joint applications were faster, more consistent, simpler and technically superior.

     Having seen the success of the TPS product, Raychem created the WPC sleeve (wraparound pipe coating).  After a few iterations, WPC eventually became WPCT (when the Thermal indicator was added into the backing).  Now, WPCT was able to be wrapped and shrunk around any size pipe which product a LOT more flexibility to the industry. 

     Now here we are nearly 50 years later, and WPCT and TPS are still cornerstones of the Seal for Life corrosion prevention catalog of products.  

     TPS is availabe in 18" lengths.  WPCT is available in 11", 17", 24" and 34" widths (customs available as well).  Would love to chat with you about your upcoming project!  

     

Heat Shrink Sleeves: Essential Information for Accurate Quoting

Want help? Contact: steve@jsicoatings.com

In the realm of purchasing and procurement, field joint coatings often find themselves at the tail end of the decision-making process. These coatings, while crucial, are frequently addressed in the eleventh hour, resulting in a significant portion of our orders falling under the "emergency" or "hot tail gate rush" category. At Joint Specialists, we understand this reality and strive to provide timely and reliable solutions.

As a distributor of Raychem products, we take pride in our ability to ship 95% of orders on the same day they are received, even under urgent circumstances. However, even for these expedited requests, we require some fundamental information to ensure the proper recommendation and pricing of our heat shrink sleeves. While obtaining the Field Joint Coating Specification makes our job significantly easier, it often involves sifting through extensive technical documentation. Nevertheless, the basic sleeve information we require includes the following:

1. Outside Diameter of the Pipeline: This measurement helps us determine the appropriate size of the shrink sleeve needed for the application at hand. Understanding the pipeline's diameter enables us to select the most suitable product from our range of options.

2. Operating Temperature: Covalence, the manufacturer of our shrink sleeves, produces a variety of products with different adhesive properties. The operating temperature of the pipeline plays a vital role in adhesive performance. Knowing this information allows us to recommend the most effective heat shrink sleeve for the specific temperature conditions.

3. Factory Applied Coating: It is important to consider the compatibility of adhesives with the existing factory applied line coating. Not all adhesives work harmoniously with every type of coating. For example, hot melt adhesives are generally not compatible with Polypropylene coatings. Identifying these potential issues in advance helps avoid costly discoveries during field operations, such as on a pipe lay barge where every day of operation carries significant financial implications.

4. Cutbacks: A cutback refers to the exposed steel surface between the factory applied coating and the end of the pipe. To determine the amount of bare steel present at a field joint, we multiply the cutback measurement by two. This calculation aids us in selecting an appropriately sized shrink sleeve for optimal coverage and protection (refer to resources [here] and [here] for further details).

Additionally, we require information regarding the specific application in which the heat shrink sleeve will be used. Factors such as whether it is a standard "drop in the ditch" pipeline, a road bore, a directional drill, a high-temperature line, an onshore or offshore project, or even a deep-water scenario, all influence our product recommendations. Understanding these details ensures that we provide tailored solutions for diverse operational environments, taking into account any unique challenges or requirements associated with each application.

We acknowledge that the amount of information requested may initially seem overwhelming or daunting. However, it is essential to recognize the significance of field joint coatings in every oil and gas pipeline joint. In fact, these coatings are a requirement rather than an option. Embracing this opportunity to enhance your sales numbers, increase profitability, and, perhaps most importantly, provide valuable service to your customers, who might otherwise choose an unsuitable product, is crucial. Furthermore, by partnering with Joint Specialists, you gain access to product experts who are just a phone call (936/321-3333) or an email (steve@jsicoatings.com) away. We are here to support you, leveraging our expertise to ensure your success.

Rest assured that with Joint Specialists, the seemingly complex task of selecting and quoting heat shrink sleeves becomes more manageable. We are committed to streamlining the process, offering efficient solutions, and delivering exceptional customer service. Contact us today to explore how we can assist you in making informed decisions and meeting your field joint coating needs

Road Bore Coating Post-Pull Analysis: DIRAX

DIRAX Post Pull Analysis

     We had a unique opportunity here recently.  On a large project utilizing some different two part liquid epoxies as their field joint coating, it was quickly determined that the epoxies were being damaged  beyond acceptable levels during the pull through.

     Now, I want to be clear - this was an extremely difficult pull.  There were large, razor sharp rocks sticking in the bore that were causing significant damage to anything that was being pulled through.  In my sixteen years of experience, I've never seen damage like this done on a lubricated directional drill pull through.  Never.  So I'm not saying there is or was a problem with the epoxies - I'm simply saying that they did not survive the incredibly challenging forces they were facing underground.

     The end user (after fully evaluating the system) decided that they would put a DIRAX shrink sleeve on the outside of the two part epoxy in order to add significant, added physical protection to that field joint coating.  Installations were done as normal when applying the two part epoxy - and then the DIRAX was installed directly on top of it (after the two part had cured).

     This introduced a 150+ mil layer of fiber reinforced polyolefin / polyamide material in the hopes that the DIRAX could act as a sacrificial coating preventing any damage from getting to the two part epoxy.  Fortunately, the DIRAX that was on the leading end of the pull through was pulled all the way through the bore so that it could be inspected.  The DIRAX was then cleaned off with a rag and a bottle of water.  Here was the result:

DIRAX after being pulled through a large directional drilling bore hole.

     Clearly there was a small amount of mud and dirt still left on the DIRAX sleeve, but all in all its performance was outstanding.  No tears in the sleeve; no holes in the sleeve, no wrinkles in the sleeve.  The DIRAX came through several hundred feet of being dragged through a hole and looks exactly as it looked just moments after installation.  DIRAX is an absolutely incredible product. 

DIRAX Case Study

DIRAX Shrink Sleeve Case Study

(What happens when a road bore goes bad?)

     Have you ever noticed that some times it is when things go horribly badly that you can often learn the most?  It could be something about yourself, could be something about a friend, or it could be something about a product that you've been selling for more than a decade.  In this case, it was the latter. 

 

     A few years back our DIRAX product was installed on a 24" OD pipeline that was going to be involved in a 2400 foot bore.  This was a pretty simple and straightforward application.  In more recent years, we've seen DIRAX put through much, much more demanding conditions than this one (as just one example a four pipeline road bore bundle).  In past years, we've seen DIRAX installed on pipe as large as 48" and come out completely unscathed.  So, a 24" line?  What could possibly go wrong?

 

     The bore hold was drilled without major incident, but as the pipe was being pulled through; very near the end of the 2400 feet length - something catastrophic happened.  This story would be dramatically more interesting if I could tell you what that catastrophic incident was - but (spoiler alert) - I can't.  Something happened though and they were forced to pull the pipe back out.  BUT, after they'd gotten the pipe 1200 feet out of the bore hole; the pipe got 'stuck'.  As a result - they were only able to recover 1200 feet of the 2400 feet.  So 1200 feet out and stacked and available for inspection....and 1200 feet trapped in a dark, dirty, muddy hole - never to be seen again.

 

     So, how did the DIRAX hold up on the journey?  How did the dual layer FBE hold up on the journey?  Let's look at a few photos:

 

      What we saw was that the DIRAX outperformed the factory applied coating even though it had been asked to do more than what it was designed for (DIRAX is really designed as a 'one way' coating - meaning the added wear cone / leader strip is designed to offer extra protection but only when installed on the leading edge).  So while we do see some light damage (over the mainline coating - not over the bare steel), we see more damage on the dual layer. 

 

     In addition, in every spot, no matter the direction it was pulled, the DIRAX served its main purpose - protecting the S1301M epoxy that was installed on the bare steel of the pipe to act as the primary corrosion coating and bonding agent between the bare steel and the DIRAX sleeve. 

 

     It isn't often we get access to such an unusual pipeline job where we are able to inspect our product and the condition it is in on the heels of it being put through the absolute ringer.  I must say I was pleased, but not surprised by the result.  

     

Epoxies and PE (Part 2)

Do Epoxies Bond Well to PE?

     I received a comment from yesterdays post (do epoxies bond well to PE) and I realized that I'd failed to address one very important aspect of that discussion.  Here was the message I received:

"If epoxies don't bond well to polyethylenes, how do you properly coat field joints on 

three layer PE coated pipelines??"

     Oops!  In my mind, yesterday's article was all about stand alone epoxies being used with PE coated lines (in my mind, I was picturing epoxy with a two layer PE; or with a solid film PE backed tape).  

     Thank you my friend for asking this question!  When coating the girth weld of pipe with a plant applied three layer coating -- of course you are going to utilize an epoxy as the primary corrosion protection on that field joint.  Anytime an end user has spent the money to put a high performance coating like TLPE on their pipeline; it makes absolutely sense to recreate a similar three layer PE coating on the field joints (a la` HTLP60 and HTLP80). So please understand, there is a difference here between an epoxy being used as one component of a three layer system; and an epoxy being used as a stand along coating where it is expected to bond/seal to a polyethylene directly.

     In many cases, on three layer PE coated pipe, there are two cutbacks to consider (three if this is an offshore pipeline as there will likely be a concrete cutback as well); the FBE cutback and the PE cutback.  In many cases, the TLPE line will have a "toe" of FBE sticking out.  This is perfect as liquid epoxies generally bond quite well to FBE.  This also allows the field joint to be coated bonding epoxy to epoxy; shrink sleeve adhesive to PE and shrink sleeve adhesive to epoxy.  All proven; all reliable, all cohesively bonded.  

     Please note - nothing I've written here says that epoxies will bond to PE.  So please be aware that there is a world of difference between the two scenarios presented here in the last 24 hours.

Pipeline Coating Supply and Technical Help

Pipe coatings are critical to the health of any steel pipeline.  In the United States, the dominant mainline factory applied coating is fusion bond epoxy.  In other parts of the world, three layer polyethylene coatings (which generally include a layer of fusion bond epoxy as one of the three coating layers) are more dominant.  The question any pipeline corrosion engineer has to answer is: "what type of coating am I going to use for the field joints?"

A field joint is the area of bare steel where two pipes are welded together.  In the plant, a pipe can't be coated from end to end, since that would result in that coating be damaged during the welding process.  Instead a pre-determined space at each end of the pipe is left bare (called a cutback).  In the field, as the pipeline is constructed, the contractor is left with somewhere in the neighborhood of 2% of the pipeline to coat (~12" or less of every 40 feet).  Of course, that contractor will be working from a specification which will let them know what coatings are acceptable in the end users eyes for coating those sections.  Sometimes, the contractor has their choice from a number of different pipeline coating technologies.  Other times, that contractor can choose from a single technology.  Sometimes the contractor is directed to use a specific product, from a specific manufacturer, from a specific technology.

If it sounds like it can sometimes be confusing; it can be.  With multiple technologies,  multiple manufacturers and a wide range of product quality, it is very difficult to find valuable, accurate, honest information.  The field joint coating (as mentioned above) represents only 2% of the pipeline coating.  Beyond that, the pipeline coating is only half (more or less, depending on who you talk to) of the corrosion prevention system (cathodic protection being the other).  Now add in things like backfill, rockshield, soil condition analysis and other factors and it quickly becomes clear.  Field joint coating is incredibly critical and important...but also a very small factor when considering the entire scope of building a pipeline.  If YOU are familiar with all of the intricacies of all of the different technologies and manufacturers; then you are a rare bird indeed!
Too often, decisions are ultimately made based purely on material cost.  I certainly understand that costs must be analyzed; business exist to make a profit after all.  But, you need someone on your side that can give an idea of installed costs rather than just material costs.  A look at the whole picture is often much, much more beneficial than a simple look at one single cost factor.

As a general rule, there are 4 current, commonly accepted field joint coating technologies (and in some cases components are mingled to create a multi-technology coating system. 

These technologies are:
- Fusion Bond Epoxy (FBE).  Generally accepted in the USA as the premier mainline coating, it can also be put on field joints.  Requires induction heating coils and flocking equipment.
- Heat Shrink Sleeves - More than 30 years of successful use history.  Many different products designed for specific pipeline operating conditions and applications.
- Two Part Epoxies - These stand alone epoxies mimic (in some ways) a fusion bonded epoxy.  Mixed and generally hand applied in the field.
- Cold Applied Tapes - Not as commonly used as they once were, this technology certainly still has a place in the market under certain conditions (if you're using the right manufacturer's product).

DIRAX Heat Shrink Sleeves / DIREX Heat Shrink Sleeves

DIRAX Heat Shrink Sleeves / DIREX Heat Shrink Sleeves

Frequently Asked Questions about Dirax Shrink Sleeves

Q:  Is it DIRAX or DIREX?

A:  The correct nomenclature is DIRAX - but I've seen DIREX written many, many times on inquiries, purchase orders and even on specifications!

Q:  Do we have to use the S-1301M epoxy with the DIRAX sleeves?  Can we use only the sleeve?

A:  No.  The S-1301M must be used or the sleeve won’t bond properly to the pipe.

Q:  Will we receive enough epoxy to successfully install all of the DIRAX sleeves?
A:  Yes. If the contractor is organized and has the proper number of field joints welded, cleaned and prepared for coating before the epoxy kit is mixed.  There are often unforeseen events that may lead to extra epoxy being needed.

Q: Do we need to wait until the epoxy cures to install the sleeve?

A:  No.  Install the sleeve over the wet epoxy.  The sleeve and epoxy are designed to work together.

Q: Do you have any tips for most efficiently using the epoxy?

A: Yes.  Be sure you are properly preheating the pipe.  This will allow you to put the epoxy on in a very thin coat (which is how it is supposed to work) and avoid wasting epoxy.

Q:  It is cold outside and the epoxy is very, very difficult to mix.  Is this normal?

A:  In cold weather, the epoxy does get thick.  We recommend storing the epoxy in a truck or building so that it doesn’t get so cold. 

Q:  We ran out of epoxy and need some immediately, can you overnight it to us?

A:  No.  The epoxy is a hazardous material and is not packaged in a way that allows overnight shipments.  We can ship via freight truck or via UPS ground.

Q:  How long do we have to wait before we can begin the bore/pull?

A:  The epoxy layer of the sleeve must be cured and the sleeve must be cool before pulling.  This typically occurs within 20-30 minutes but since cure times are greatly influenced by ambient weather conditions, only the people onsite can determine when exactly the epoxy cures.

Q:  Do we put epoxy on the steel and the FBE/ARO? 

A:  Yes.  The epoxy needs to be everywhere that the sleeve will be (and the leader strip which is the 3” wide sleeve).  The only possible exception is when you are working with PE coated pipe.

Q:  Do we wrap the sleeves around the pipe snugly or with a large ‘gap’ underneath the pipe?

A:  Wrap the sleeve snugly.

 

Q:  Is there a limit to how large of a pipeline can use DIRAX?

A:  No there is not.  We’ve had extensive evaluations in the past on lines as large as 42” and the DIRAX sleeve survived the bore with flying colors

Q:  What are the standard widths of DIRAX and which one should we get?

A:  Standards are 12”, 17” and 24”.  At a minimum, we recommend that a sleeve be wide enough to coat all bare steel and overlap onto adjacent factory applied coating by at least 2” per side.  Some end users specify that the overlap onto adjacent factory applied coatings must be at least 3”, 4”or even 6” per side.