Covalence Shrink Sleeves (formerly Raychem)

Seal For Life’s Covalence brand offers a comprehensive range of heat shrinkable products designed for corrosion prevention, mechanical protection, and sealing of pipelines, including field joints and pre-insulated pipe systems. Below is an overview of their main product offerings and applications:

• Covalence provides both 2-layer and 3-layer heat-shrinkable sleeves.

• These sleeves feature irradiation cross-linked polyethylene or polypropylene backings, combined with adhesive layers (either visco-elastic mastic or co-polymer hot melt) tailored for different pipeline operating temperatures and environments.

• The 3-layer systems often include an epoxy primer for enhanced adhesion and are compatible with modern multi-layer mainline coatings, creating a monolithic protection system.

• : A two-layer field-joint coating system designed for corrosion protection of pipelines operating at ambient temperatures. It is among the most widely used solutions for girth weld protection.

• : High-performance, three-layer sleeves with epoxy primer, designed for pipelines with higher operating temperatures and demanding environments. These sleeves offer excellent resistance to cathodic disbondment, hot water immersion, and soil/thermal movement stresses - HTLP60 & HTLP80

• : Specifically engineered for directional drilling and applications requiring extra mechanical strength - DIRAX & CCS Material used to make Caseals and Flangeseals.

• : Designed to provide durable sealing solutions for pre-insulated pipe joints, protecting against moisture ingress and maintaining thermal integrity.

• : Includes joint casings, foaming hole closures, primary joint foam seals, end caps, and sealants to support a wide range of pipeline configurations and field conditions.

• High electrical resistance and low permeability for optimal corrosion prevention.

• Designed for easy installation with minimal tools and surface preparation.

• Approved by major testing agencies worldwide, ensuring suitability for diverse field conditions and compliance with global standards such as ISO, EN, AWWA, NACE, and GOST.

• Proven performance record in major pipeline projects globally, including oil, gas, and water transmission lines.

Product Type	Layers	Key Application	Notable Features
WPCT	2	Field joint corrosion protection	Ambient temperature pipelines
HTLP Series	3	High-temp, high-stress environments	Epoxy primer, soil/thermal resistance
Fiberglass-Reinforced Sleeves	2–3	Directional drilling, mechanical stress	Extra strength, abrasion resistance
Pre-Insulated Pipe Sleeves	2–3	Pre-insulated pipe joints	Moisture and thermal protection

Covalence’s heat shrinkable products are trusted globally for their reliability, versatility, and ease of installation, making them a leading choice for pipeline protection and sealing needs.

 Lead Time for Covalence Shrink Sleeves

      Once upon a time, Covalence Heat Shrink Sleeves were called RAYCHEM (many people still remember that name:

     Since 1989 we have been a stocking location for Raychem (now Covalence) Shrink Sleeves.  We specialize in a few things:

• We are knowledgeable about the product
• We keep a large stock of inventory
• We try to ship all orders out within one day

     So, lead times are generally very SHORT.  A few of the Covalence products that we stock and make in our facility in Conroe, TX 77385:

• DIRAX - directional drilling field joint coating
• WPCT - basic mastic shrink sleeve rated for use up to 140F
• WPC100M - mastic shrink sleeve rated or use up to 212F (in some circumstances)
• WPC120 - hot melt adhesive shrink sleeve rated to 251F
• TPS - WPCT in a slip on / tubular form
• Caseal - high expansion sleeve for sealing between a casing and a carrier pipe
• Flangeseal - high expansion sleeve for protecting a flange
• Flexclad - heat shrink tape
• HTLP60 and HTLP80 - three layer coating system
• S-1301m Epoxy that is used with products like DIRAX and HTLP

Give us a call with any questions!  Would love to chat about your next project!  936/321-3333

Sizing for Sealing a Flange with Flangeseal

 How do I Know What Size to Order: FS-Flangeseal and AQW-FPK (Flange Protection Kit)

An installed Covalence FS (Flangeseal)

     Coating a flange can be tricky.  You've typically got a significant size difference between the outside diameter of the flange - and the diameter of the pipeline.  You've also got a number of bolts that could have sharp edges.  You've got a gasket of some kind that you'd likely don't want to covered in anything permanently (that would prevent you from re-entering that flange if it was necessary.  You've also likely got some amount of uncoated pipe where the flange is welded in.  There are a lot of important data points there.  Let's try and break it down so it is a bit simpler.

     Typical flangeseal nomenclature will be something like this (I'll give a few examples):  

FS 24000-24 -- this is for a flange with an ACTUAL OD of 24.0".  This FS is supplied 24" wide (we'll get more into that below).

FS 36000-36 -- an FS for a 36" OD Flange that is supplied at 36" wide.  

FS 12750-24 -- an FS for a 12.75" OD Flange that is supplied at 24" wide.

     So, the first number is VERY important!  That tells us how to make the Flangeseal so that is long enough to wrap all the way around the flange and meet back up with itself.  An FS 12750 would never work on a 24" OD flange --- it would be like someone with a 36" waist trying to button up jeans that are made for a 22" waist.  

     The second number is the width of the flange as supplied.  That is slightly trickier to figure out.  Let's say you are working with a 24" OD Flange and a 12.75" OD Pipe.  In addition, let's say that flange is 4 inches wide itself and there are 4 inches of uncoated pipe where the pipe and flange connect.

     First thing I look at:  24" OD flange down to a 12.75" OD pipe.  Picture the sleeve installed.  The sleeve is going to 'step down' from the peak of the flange down to the pipe surface and nearly 6" of the sleeve "width" is going to be lost on that vertical of the sleeve shrinking.  Does that make sense?  Simplify it by picturing yourself cutting a strip of duct tape that spans from your kitchen island down to the floor and across to the wall.  You would have to measure - the number of inches you want it to be attached to your kitchen island -- and the distance from island to floor -- and the distance across floor to wall.  In this paragraph - the step down from outermost flange to pipe is like the distance from the kitchen island to the floor.  

     So right there - with this 24" to 12.75" dimension we know we are going to lose 6" of our sleeve width TWO TIMES (have to figure this step down will happen on both sides of the flange.  So that is 12" of our width "used" already.  In addition - the flange is 4" across (which includes where the bolts are, etc).  We've now used 16" of our sleeve width (12+4).

     Now let's add in that there are 3" of bare steel adjacent to the flange on both sides.  That is 6" of bare steel (total - we have to add them together) AND we still need to overlap onto good pipe coating by at least 3" per side (another 6").

     That leaves us (in terms of sleeve width) with:

• 12" of width used to bridge the gap between flange and pipe
• 4" of width used to cover the flange itself
• 6" of width used to cover bare steel
• 6" of width used to overlap onto good coating

12 + 4 + 6 + 6 = 28"

     The minimum FS width that could work on this configuration is 28".  Our standards are 24" and 35.5" --- so the only option here is to use a 36" wide Flangeseal (24" would not properly seal).  

The Best and Simplest Way to Seal a Buried Flange

 How to Prevent Corrosion on a Buried Flange

An installed Covalence Flangeseal

     So, you need to protect your flange (that is going to be buried eventually) from corrosion.  The Covalence (formerly Raychem) FlangeSeal is an excellent option for you.

    Flange Seal offers a high expansion, fiber reinforced backing and an extremely aggressive mastic sealant.  Shipped out with a strip of cardboard - which is wrapped around the Flange first - means that Flange doesn't get too messy and can be re-enterable one day if you need it.  Installed using a propane torch, it just doesn't get any easier than an FS Flangeseal installation.

     But there are three very important bits of information that you need before you can quote or order a Flangeseal.  

FIRST:  You must know the actual outside diameter of the flange you'll be installing on.  There are a number of flange manufacturers out there and many different types of flanges.  Simply knowing "300# 12 inch" just isn't enough to avoid a possible problem.  The Flangeseal must be large enough to wrap around that flange -- so prepare yourself -- you will be asked:  "What is the outside diameter of the FLANGE?".

SECOND:   You need to know the OD of the pipeline!  We need to be certain that the Raychem Flangeseal is able to shrink enough to properly wrap around the flange -- and shrink all the way down and seal to the pipeline.  

THIRD:  We will need to know if your specific parameters can be met with a 24" wide Flangeseal (FS) or if you need to look at using a 36" FS?  

     With those three bits  of information:

1. Actual Outside Diameter of the Flange
2. Outside diameter of the pipe
3. Width of the FS required

You'll have that Flange protected in no time!

Have questions?  Reach out:  Steve@jsicoatings.com  or   936/321-3333