Bore Bumpers for PP Coated Pipelines
|Here you see one of our BBS Bundled Bore Bumper sleeves installed in the field (not on PP).|
- Peel Strength - based on our experience with the product, we don't believe peel is any factor here at all. For the system to be put into peel would require a set of circumstances that are pretty much unimaginable.
- Impact Resistance - the system has excellent impact resistance of course, but we don't believe this characteristic will come into play here.
- Penetration Resistance - again, not a factor. This system has excellent penetration resistance (I would say unmatched) but the chance that a penetration occurs that is somehow eventually able to dislodge and/or move the bumper is very difficult to imagine.
- Cathodic Disbondment Resistance - again, not a factor. This material is not acting as a coating (but when it does act as a coating it exhibits excellent CD resistance).
- Shear Resistance - Bingo. We have a winner. The forces exhibited on the profile of the bumper will put front edge of the sleeve under shear forces. The front of the sleeve will see shear forces and the weight of the other pipelines along with the force of the pull will exhibit shear forces.
The samples came in and we began determining the best way to evaluate shear strength. The contractor already had a system in place that required abrading and heat treating the polypropylene for his field joint coating procedures, so the first simple step was to expect that same treatment for the areas where our BBS sleeves would be bonding to the factory applied polypropylene. Clearly step one was going to be: prepare the PP samples with abrasion and heat treating.
Next we bonded stamps of our material onto the PP samples. Our base bonding product exhibits shear values that pass at 80 pounds per square inch when installed on epoxies and dual layer FBE. DIRAX (the product in question) has been used successfully hundreds of thousands of times, there is no question that the shear resistance values of DIRAX are more than sufficient to survive the forces associated with a directional drill.
Using a testing system that we developed here, we were able to determine that our material samples installed directly on the PP samples held up at 80 pounds per inch without failure. The bond could have taken more than 80 pounds, but we saw no real reason to test to failure. In any case, given that the single most important technical value in this application is shear resistance, and given that our product exhibits exemplary shear resistance; as high as has been successfully used many, many times in directional drilling applications, we felt incredibly comfortable to approve the use of our product for this specific application. I am hoping we will be able to get photos from the field of the project which is going on as we speak. If I can - check back in as they will be posted here.