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Wednesday, September 2, 2015

Covalence Seal for Life Tubular Heat Shrink Sleeves

Covalence Seal for Life Tubular Heat Shrink Sleeves

      Covalence is a division of Seal for Life Industries (which is a division of Berry Plastics).  Formerly going by the name Raychem, our tubular heat shrink sleeves have gone unchanged over the years in spite of the manufacturer name changes.  TPS Tubular heat shrink sleeves are commonly sold for pipelines 2" thru 8".  Available in 18" and 9" widths, TPS has been successfully installed and used for decades. 

     TPS heat shrinkable tubes are compatible with standard pipe coatings including PE, FBE, Tapes, Coal Tars and Polypropylenes.  The comprehensive range of sizes allows all pipe diameters up to 8" (200mm) to be coated.  From nominal pipe sizes 10" and larger, we recommend the appropriate wrap around product be used. 

     Installation of the tubular heat shrink sleeve is carried out directly on the cleaned and dried (pre-heated) pipe surface. No primer is required to promote adhesion.  TPS is compatible with standard commercial mill applied coatings.  In the event of mechanical damage, the sealing adhesive flows and seals off the damaged area (self healing effect).  No special tools are needed which leads to lower installation costs.  Continuous, tubular design means no closure patch is necessary (tubes must be slided over the pipe prior to welding the joint together).  The thick walled structure of the cross linked heat shrinkable material gives it high impact strength and penetration resistance. 

Tubular Heat Shrink Sleeve Installation Steps

  1. Slide the tubular heat shrink sleeve, complete with its protective release paper, onto the pipe before the joint is made.
  2. Prepare the pipe surface that is to be coated with a power wire brush; removing all loose and foreign materials.  No primer is required.
  3. Using a propane torch, preheat the surface of the pipe and adjacent factory applied coating to about 60C.  
  4. Position the sleeve over the welded joint so that it overlaps the mill applied coating by at least 50mm (2 inches).  Remove the release paper. 
  5. Working from the center outwards, heat the sleeve with a soft yellow propane flame, keeping the torch in steady and circumferential motion.

You will know the tubular heat shrink sleeve is installed correctly when:

  1.  The complete sleeve is in contact with the surface of the pipe, it is smooth and has no cold spots or air enclosures.
  2. Adhesive flow is evident at both sleeve edges along the circumference of the pipe.
  3. The overlap on the mill applied coating is as specified.  
     For technical help and pricing information on our Tubular Heat Shrink Sleeves - contact us at 936/321-3333 or

Monday, August 31, 2015

Shrink Sleeve Selection Criteria

How To Select The Proper Shrink Sleeve

     Covalence (formerly Raychem) heat shrinkable sleeves are the world leader in corrosion protection of pipeline girth welds.  They are specifically designed to combine ease of field installation with a level of performance that matches, or exceeds, that of the mainline coating. 

     Project specifications and or local standards must be observed, when specifying a shrinkable sleeve for protection of girth welds.  To ensure optimal choices, the following parameters must be considered.

Pipe Operating Temperature

As temperature increases, the overall resistance of a coating generally decreases.  Therefore, in order to ensure adequate lifetime, it is important to select a coating that has been correctly performance tested at maximum operating temperature.  Covalence mastic coated sleeves are available for temperatures up to 100C.  Hotmelt sleeves are available for temperatures up to 120C.

Pipe Coating Type

Covalence / Raychem heat shrinkable sleeves are compatible with all commonly used pipe coatings, although somewhat different installation procedures may be required, depending on the line coating employed.  The sleeves will adhere to FBE, PE, PP, ARO and CTE coatings.  Some polypropylene coated pipes require special heat shrink sleeves.  When using polypropylene pipe coating, please consult Joint Specialists for assistance in selecting the appropriate heat shrinkable joint protection sleeve.

The HTLP three layer system is often used on three layer PE pipe coatings to provide factory original quality to the field applied girth weld protection.  The same system can also be applied on two layer PE. 

Cutback Distance

Different pipe coatings require different coating cutbacks at the weld joints.  Our standard sleeve widths are 11", 17", 24" and 34".  Custom widths are generally available for no extra charge.

Outside Pipe Diameter

When buried, larger diameter pipes incur higher soil stress due to the weight of the soil above them. These stresses create tangential forces, which in low performance coatings tend to cause wrinkling at the two, four, eight and ten o clock positions on the pipe.  The best way to combat these forces is with high modulus polymer shrink sleeves coated with high shear strength adhesive.

Covalence heat shrinkable sleeves possess the highest modulus in the industry, while the hotmelt adhesives are made of the finest copolymers.  Raychem hotmelt coated shrink sleeves provide the greatest resistance to soil stresses on all diameters.  Below 20 inches diameter, Raychem's high performance mastic coated shrink sleeves often provide a good balance of performance, economy and easy of installation.

Adverse Soil Conditions

In adverse soil conditions where heavy soil stresses, corrosive soils or water logged areas are expected, the use of soil stress free coatings with excellent cathodic disbondment and long term water immersion resistant is essential.

HTLP60, HTLP80, WPC120 and ROCS / DIRAX are all outstanding in this respect.  They have consistently been rated the best girth weld coatings in tests carried out by major pipeline companies worldwide.

Pipe Laying Method

Directional drilling places tremendous stress on a pipe coating - and especially on the girth weld coatings.  Raychem DIRAX kits are designed to protect girth welds in this punishing environment.  The DIRAX system starts with the application of an epoxy primer coating, on top of which the DIRAX sleeve is installed.  The sleeve is a fiberglass reinforced polymer laminate with an edxtremely high shear resistant crystalline adhesive.  In numerous tests and customer trials, DIRAX surpasses even the toughest conditions.

For laybarge installed pipelines, WPCT, WPCZ, WPC100M are ideal girthweld coatings, being easy and quick to install and fully resistant to the pour of hot marine mastic infills and the heat generated by polyurethane foam infills.  They are compatible with all commonly used main pipe coatings.  For elevated temperature lines use WPC100M which has a 100C continuous rating subsea.

For reelship installed pipelines, HTLP80 has a proven track record on three layer PE lines, even when reeled or unreeled under tropical conditions.

Climatic Conditions

Extreme climatic conditions (hot, cold, wet, etc) can have an impact on the sleeve selection and the installation method.  In cold conditions it will be necessary to organize proper field storage; rain requires a tent.  In hot climates it may be beetter to select a high temperature sleeve, even for a low pipe operating temperature, as the pipe could be exposed to very high ambient temperatures for an extended time during construction.

Recommended Pipe Preparation

Pipe preparation depends upon the project specification and the resulting choice of products.  In order to obtain the desired performance, pipe preparation must be carried out in accordance with the relevant product installation instructions.

Mechanical Resistance Class

Depending on the mechanical requirements of the local or project specification, the appropriate sleeve construction (thickness) is selected.  

Thursday, August 27, 2015

Raychem / Covalence Heat Shrink Sleeve Advantages

Advantages of Covalence Shrink Sleeves (formerly Raychem)

Demanding Applications

In order to protect metal pipe structures in contact with an electrolyte (soil, water) coatings need to have a high electrical resistance and low permeability to hydrogen and oxygen. 
The coating must also be physically strong and chemically stable.
Additionally, the requirements of particular applications, like high operating temperatures necessitate specific tailoring of all pipeline coatings, including heat shrinkable sleeves.

Optimal Solutions

To provide the optimal solution for each application, Raychem offers a range of products based on an irradiated crosslinked polyethylene carrier, combined with a hot melt or mastic coating applied in the factory to that heat shrink backing.
The main purpose of the crosslinked carrier (the actual heat shrink sleeve), called the backing, is to provide a strong barrier against electrical current, permeation and mechanical forces.
The adhesive assures long term bonding of the backing to the pipe and provides added electrical resistance (which is a good thing in spite of the propaganda you are regularly exposed to) and mechanical strength.
Thickness of the backing and adhesive depend on the application requirements. 

To sum that up:  Strengths of the heat shrink sleeve include (but are not limited to):
- Chemical Resistance of heat shrink backing and the selected adhesive
- Flow and fill of the hot melt adhesive or mastic sealant
- Mechanical Strength of the heat shrinkable backing (which can potentially be multiple layers and include fiber reinforcement)
- Electrical Resistance of both the backing and the adhesive.  A coating with no electrical resistance means your pipeline is going to rely on your CP system almost solely for corrosion prevention.  Why not just leave the field joints as bare steel if that is your goal?

Three Layer Coatings

For the increasingly common (in Europe, South America and Asia) three layer factory applied pipeline coatings, Raychem / Covalence has developed a three layer field applied field joint coating.  To provide a homogeneously coated pipe surface in the girth weld area, a layer of two component epoxy is first applied to the surface of the pipe.  A specially designed shrink sleeve is then applied over the wet epoxy. 
The three layer heat shrinkable coating system performs extremely well in resisting cathodic disbondment.  It also offers high shear resistance against soil load and consequently ensures long service life. 

High Reliability, High Performance

Raychem (now called Covalence) has more than 40 years of experience in the development and manufacturer of heat shrinkable products.  Continuous improvement ensures state of the art performance.  Approval by testing agencies around the world guarantees suitability for individual applications and field conditions. 
- Two layer and three layer constructions complement wide range of pipe coatings
- Top quality hotmelt, copolymer coated sleeves resist elevated pipe operating temperatures and soil stresses on all pipe diameters.
- Mastic coated shrink sleeves balance performance, economy and easy of installation.
- Three layer sleeves with epoxy primer and hotmelt copolymer have excellent resistance to both cathodic disbondment and hot water immersion, even at maximum rated operating temperatures.
- Fiberglass reinforced heat shrink sleeves withstand the high stresses of directional drilling
- Self-healing adhesive slow automatically repairs minor mechanical damage

Low Installation Costs

- No primer required for two layer heat shrink sleeve systemes - install directly on cleaned and preheated pipe surface
- No waiting for primers to cure.  The shrink sleeve is installed directly over the wet epoxy
- Simple tools such as a hand brush, power brush or blast cleaning and propane torches are used for installation of the heat shrink sleeve
- All products available as Uni sleeve construction.  Uni sleeve means the closure strips are attached to the shrink sleeve here in our shop allowing for quicker installation in the field and dramatically fewer field issues.
- Easy to understand installation instructions are shipped with every product; in every box of shrink sleeves.  Clear product labelling on the outside of the boxes allows rapid on site installation.

Premium Service with Joint Specialists

To place an order or inquire about products, contact us at 936 /321-333 or email to  We pride ourselves on offering the best customer service in the industry with very quick turnarounds on information, pricing and delivery.