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HTLP60 Application Guide
HTLP60 is an excellent field joint coating option for any pipeline that will operate at or below 140F. It would not be used for road bores or directional drills (if you're curious why, you can look HERE).
Replicating a factory applied three layer PE coating, HTLP60 utilizes a two part epoxy primer as the primary corrosion coating. The radiation crosslinked sleeve (coated with a high shear hot melt adhesive) is then wrapped and shrunk onto that still wet S-1301m epoxy. The adhesive and the epoxy are specially designed to bond both physically and chemically, resulting in a very high performance product. The Canusa equivalent to this product would be called a GTS-65.
So now let's get into the application instructions:
1. Be certain you have the appropriate sized HTLP60 /UNI sleeve, the S-1301M epoxy and the other components ('a' container, 'b' container, applicator pad, stir stick, latex gloves)
2. A proper propane torch (not a rosebud or welding torch) with a hose, torch head that will create a broad bushy flame and a REGULATOR so that you can control your flame.
3. You will want a contact pyrometer in order to be certain your preheat is on point.
4. Silicone roller
5. Standard safety equipment as dictated by the safety protocols on your job
6. Clean the exposed steel and adjacent pipe coating to be covered by the HTLP60 shrink sleeve. Remove all contaminants such as oil, dirt and grease. Use a solvent that contains no grease or oil materials.
7. If the factory applied coating is not beveled, chamfer the edges of the coating to an angle of 15-30 degrees. Inspect the edge of the existing pipe coatings. Disbonded sections have to be trimmed off and the coating edge has to be beveled again. To avoid possible contamination, use a scraper.
8. Grit blast or sand blast the steel surface to remove loose and foreign materials. The surface should be cleaned to SIS 055900 - SA 2 1/2
9. Grit blast or sand blast the adjacent pipe coating over a distance of at leaset 4". The total width should be approximately 2" larger than the width of the HTLP60 sleeve you are going to apply.
(Note: prior to blasting it is recommended to preheat exposed steel to 104-122F to avoid flash rust formation.
10. Wipe the surface to remove dust and remaining blasting materials. Use a clean dry cloth or air blow.
11. Dose the two component Raychem / Covalence S1301M Epoxy. Pour the contents of can "B" into can "A" and mix for approximately 1 minute. After use follow local regulation for safe disposal. A mixed epoxy kit has a pot life of approximately 30 minutes at ambient temperatures. As long as the epoxy primer is still liquid, it can be used.
12. For easy mixing, the S1301M epoxy primer should be used at a minimum temperature of 64F. When necessary, keep the S1301M in a heated place (truck / warehouse / etc).
13. Adjust the torch to a yellow topped blue flame of approximately 20" long. Preheat the steel and adjacent pipe coating to 140F - 194F. Preheating the substrate reduces the installation time and ensures proper bonding. Make sure that all necessary items including mixed epoxy are in close proximity before starting preheating. In bad weather conditions, use proper shielding such as a wind shield in windy conditions or a well ventilated tent in the case of rain.
14. Check the preheat temperature with a contact pyrometer. Avoid using a temperature marker that can cause contamination to the pipe surface.
15. Immediately after preheating, apply the mixed S1301M epoxy to the bare steel and the adjacent pipe coating using the included applicator pad. Total width of the S1301M should be 2" larger than the width of the HTLP60 heat shrink sleeve. Visually check the surface and ensure all bare steel and line coating is covered by the S1301M epoxy primer.
16. If not already done, you can trim the corners of the underlying sleeve in a 1/2" by 2" pattern.
17. Immediately after the application of the S1301M epoxy primer, and while the S1301m is still wet, loosely wrap the HTLP60 sleeve centrally around the welded joint. The edge of the sleeve with the trimmed corners should go on the pipe first. The sleeve should overlap in the 10 and 2 position and the overlap of the sleeve onto itself should be at least 2". The sleeve should be wrapped around the joint leaving a 1" gap between the bottom of the sleeve and bottom of the pipe.
18. Gently heat the inside of the overlapping sleeve edge and press it down onto the opposite sleeve with a gloved hand.
19. Heat the inside of the closure patch for 1-2 seconds. Position it evenly over the edge of the sleeve and press it down firmly.
20. Start heating the closure patch from one side and slowly move to the other side while pressing down with a gloved hand to ensure good bonding and eliminate air entrapment. During and after the heating, the fabric reinforcement becomes visible as an indication that the closure patch has been heated to the minimum required temperature.
21. For pipes larger than 16" OD, two installers are recommended.
22. Begin heating at the center of the sleeve and heat circumferentially around the pipe using a constant paintbrush motion. Continue heating towards one end of the sleeve, followed by the other. In case of strong wind, begin heating the sleeve from one end of the sleeve, opposite to the find and heat circumferentially around the pipe, using a constant paintbrush motion. The flame should not be held perpendicular to the sleeve, but should be directed toward the shrinking direction.
23. Continue heating towards the other end of the sleeve. Ensure that the total HTLP60 sleeve has been heated evenly and has completely shrunk tightly around the pipe.
24. During shrinkdown, occasionally check the adhesive flow with a finger. Wrinkles should disappear automatically.
25. Possible air entrapments can be reduced by post-rolling of the sleeve immediately after the sleeve has been shrunk, while the sleeve is still hot. Start rolling from the weld bead towards the sides forcing forcing possible air enclosures out of the sleeve. Special attention should be given to longitudinal and circumferential weld beads. The transition from mill coating to bare steel should also be rolled.
If necessary you can reheat to roll out air.
26. The sleeve is fully recovered when all of the following have occurred:
- Sleeve is fully conformed to the pipe and adjacent coating.
- There are no cold spots of dimples on the sleeve surface
- Weld bead profile can be seen through the sleeve
- After the sleeve is cool, the adhesive flow should be evident on both edges.
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