Visit our website:
Call: (936) 321-3333

Wednesday, November 27, 2013

HTLP60 vs HTLP80 - What is the Difference?

HTLP60 vs HTLP80

     I get a lot of technical questions emailed to me via this blog...and via our website (  These questions come from all over the world. Here is a recent questions I've received from India:

What is the difference between HTLP60 and HTLP80?  I am writing the specification for a 6" pipeline and I need to know which product you would recommend and why.

     Obviously, not a lot of information there!  Now, I know that if this project will never become an order for me.  I don't sell material into India and to the best of my knowledge (somewhat limited); Covalence has excellent coverage in terms of sales effort and distribution in India.  But, I am still thrilled that I get to be a part of the process here by sharing my product knowledge and information.  Our business is shrink sleeves.  I've been selling and studying nothing shrink sleeves for 13 years.  My father has been selling and studying shrink sleeves for 30+ years.  In a sense, I've been around "shrink sleeves" either as a profession...or as a witness to household discussions...or tagging along with my Dad to a job site when a vacation was disrupted...or working in production (cutting, bonding and processing shrink sleeves) as a high school student - for almost my entire life (my Dad went to work for Raychem when I was ~4 years old and I'm 42 now).

     When you're sharing knowledge about a product that you believe in; it is fun.  When you're helping to answer a simple question that someone has been trying to track down an answer to for weeks (which happens a lot - phone calls unanswered - referrals to disconnected phone numbers - referrals to people with no product knowledge - etc - etc) - the relief in their voice when they can finally get the answer to a simple technical question is very rewarding.  It is nice to be needed!

     In any case, all of that to say:  I'm thrilled when I get to answer technical questions and offer technical assistance - even when there is no chance of me personally getting any business.  I believe in this Covalence product line (formerly Raychem).

     So here is my answer to the question "what is the difference between HTLP60 and HTLP80?":

Dear Sir,
Thank you for the inquiry.  The basic difference between HTLP60 and HTLP80 is very simple:
HTLP60 utilizes an adhesive that is designed to withstand a continuous pipeline operating temperature of 60C or below.
HTLP80 utilizes an adhesive that is designed to withstand a continuous pipeline operating temperature of 80C or below.

Both are components of a three layer field joint coating system that utilizes a two part epoxy as one of the components of the system.  It is important that the epoxy used be a Covalence(formerly Raychem) epoxy that has been specifically designed to work in conjunction with the HTLP adhesives (generally the S1301M epoxy can be used with either as it is rated to 80C -- the S1239 can be used only with the HTLP60 as it is rated only to 60C).
There are some (what I would consider fairly minor) technical differences in the product performance as can be seen at our website (  Both products have a long successful use history.  Both products are proven. 
I'm happy to help you determine the specific part number that I would recommend for this project - but I would need to know:
- pipeline operating temperature once it is in service (design temp)
- what is the factory applied mainline coating?
- what are the cutbacks on the mainline coating?
- will this be a buried line?
- what is the quantity of field joints that will be needed? (important as some products have a minimum order quantity)
If you can answer some of those questions - I am happy to continue the dialogue!


  1. HTLP means High Temperature Low Pressure. Is that correct?

  2. Hello - HTLP originally stood for "High Temperature Low Preheat" - essentially the epoxy bonding agent is able to substitute for what would have been a very high preheat requirement to achieve the proper bond directly between the hot melt adhesive and the bare steel.

    Sleeves are not designed to withstand any kind of significant internal pressure; so pressure has nothing to do with it.