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Tuesday, October 25, 2016

TWDB Thermofit Cut Lengths

Cut Lengths for TWDB Thermofit Wraparound Duct Bands

     Ok, everything I will share here is printed on the actual TWDB boxes themselves (whether 3" wide or 4" wide).  No need to take notes.  When your TWDB arrives you will have all of this data and info right at your fingertips (literally).

TWDB Installation Instructions:
Materials and Equipment required:
- High temperature closure tape (included in the TWDB package)
- JS2601 torch or equal
- Propane tank
- Heat resistant work gloves

1: Join duct sections using internal couplers or crimped end male female type connection.  Apply sheet metal screws.  2 screws 180 degrees apart are usually sufficient.
2: Wipe joint area to remove foreign materials.  Preheat joint to remove moisture and burn off surface oil that may be present.
3: Cut TWDB to appropriate length (see sizing chart).  Center TWDB and wrap around duct joint.  Using the supplied closure tape, secure the loose TWDB end by taping in place across the width of the overlap.
4: Adjust torch to provide soft billowy flame.  Heat TWDB uniformly.  As heat is applied, the TWDB will chrink and bond to the duct to form a pressure tight seal.
5: With gloved hand pat down overlap area to ensure proper adhesion.
6: Recovering is complete when the TWDB is in 360 degree contact with duct and the molten adhesive is visible at both ends. 

The following chart is organized:  Duct Size / TWDB Cut Length
2" / 9"
3"/ 12"
4"/ 15"
5"/ 18"
6"/ 21"
7"/ 24"
8"/ 28"
9"/ 31"
10"/ 34"
11"/ 37"
12"/ 40"
14"/ 46"
16"/ 53"
18"/ 59"
20"/ 65"
22"/ 72"
24"/ 78"
26"/ 84"
28"/ 90"
30"/ 97"
32"/ 103"
34"/ 109"
36"/ 115"
38"/ 122"
40"/ 128"
42"/ 134"
44"/ 141"
46"/ 147"
48"/ 153"
50"/ 160"
52"/ 166"
54"/ 172"
56"/ 178"
58"/ 185"
60"/ 191"
62"/ 197"
64"/ 204"

Monday, October 24, 2016

Cold Weather Pipe Coating

Installing Pipe Coating in Cold Weather

     Choosing and installing a proven field joint coating can be a tough job.  There is an incredible amount of bad information out there as competing technologies focus more on bashing other products than they do on explaining the strengths of their own products.  It isn't much unlike the current political state in the US!  But as hard as it can be - when winter rolls around and we are faced with cold months; that introduces an entirely new set of challenges and obstacles to attempt to overcome.

     What are the challenges that cold weather can bring to the field joint coating process?
  • Cold pipe is generally not very conducive to accepting a bond.  Pipe must be preheated up to a warmer temp (varying by product) in order to properly bond.  When it is very cold out - this becomes more difficult depending on what your preheat method is.  
  • Cold temps often bring with them cold winds.  This works to quickly cool pipe even if it has been preheated.  Pipe must be brought to temp -- and kept at temp throughout the install.  
  • Cold temps have a significant impact on products that require a cure time.  That 3 hours cure can become 75 hours in some cases.  In some cases (under 40F as stated on some data sheets) curing absolutely will not occur. 
     So what is the solution when you are building a pipeline during seasons where temperatures are simply colder during certain months?  You have to plan for it.  Depending on your coating of choice, you may need to make sure your contractor is able to construct shelters and moveable buildings in order to protect the pipeline.  You also need to plan for how you are going to keep steel temps up during that process - it could be something as expensive as inductive heating coils or it could be something as simple as using propane torches.  It is your pipeline, so the choice is yours!

      As for me, when I get that call from someone in the field working on a pipeline spread where temperatures are very cold; I normally recommend installing a heat shrink sleeve there.  The cold temperature will be less of a factor.  Though there are many options - the first two I would look at would be:

HTLP60 - rated for use on pipelines operating at up to 60C.  A three layer coating system for the field joint incorporating a two part epoxy; a hot melt adhesive and a PE backing for physical protection.  You might be asking yourself  "wait - you're looking at an epoxy component, but the temps are cold.  How is that going to work??"  I'm glad you asked.  We preheat the steel to 140F - then we wrap and shrink the sleeve (sleeve backing shrinks at 267F).  The heat from the preheat and install is sufficient to cure all epoxy; regardless of the outside ambient temps.

DIRAX - the premier product for road bores and directional drilling applications.  Similar to the HTLP60 - it incorporates a two part epoxy, a hot melt adhesive, a fiber reinforced backing all to create an incredibly tough coating system.

In both cases , the coating system incorporates all of the strengths and advantages of a two part epoxy - without being excluded from cold weather applications.  It is a fantastic marriage of coating technologies that provide an excellent a proven field joint coating.

Friday, October 21, 2016

Shrink Sleeve Installation Time

How Long Does It Take To Install A Shrink Sleeve?

     I am often asked "how long does it take to install a shrink sleeve"?  The truth is that question isn't as simple as it sounds.  Speaking in general terms - the installation steps are:
- preparing the surface of the steel and adjacent line coating
- heating the steel and adjacent line coating to the proper temperature
- securing the closure strip
- shrinking the sleeve
     Each of those steps are impacted by a number of factors.  Including:
- how dirty and rusty is the pipe?
- is the ambient temperature 5F? 40F? 100F?  That will all effect preheat time
- is it calm? 25 mph wind? 
- what is the pipe OD?  how many installers are you using?  are you using the proper torches?

     I'm sure you see what I mean now.  A lot of factors can impact this analysis.  So the rest of this post is a real world actual example. 

16" OD Pipeline
Installed on the gulf coast (onshore)
Pipeline construction going on in early fall
Two installers working on each field joint (one on each side of the pipe)
Proper torches on site (with regulators and proper output)
Installing our WPCT product which requires a preheat temperature of 140F
Wire brushing the pipe surface of pipe that is still pretty clean as it was freshly coated in a coating plant
Experienced installers who have installed many shrink sleeves in the careers
Pipeline spread where the welders are pretty far ahead of the field joint coating crew - so no delays due to welding or xray.

180 shrink sleeves installed per day.   That equates to 1.3 miles of pipeline per day (assuming ~40 foot joints). 

Pretty fast.  I'd love to know how many joints would be coated per day if they were hand applying some kind of two part epoxy instead of applying sleeves.  How about if they were needing to put two coats of epoxy on every joint?  It would be a lot slower process I believe.