DIRAX Shrink Sleeve Case Study
(What happens when a road bore goes bad?)
Have you ever noticed that some times it is when things go horribly badly that you can often learn the most? It could be something about yourself, could be something about a friend, or it could be something about a product that you've been selling for more than a decade. In this case, it was the latter.
A few years back our DIRAX product was installed on a 24" OD pipeline that was going to be involved in a 2400 foot bore. This was a pretty simple and straightforward application. In more recent years, we've seen DIRAX put through much, much more demanding conditions than this one (as just one example a four pipeline road bore bundle). In past years, we've seen DIRAX installed on pipe as large as 48" and come out completely unscathed. So, a 24" line? What could possibly go wrong?
The bore hold was drilled without major incident, but as the pipe was being pulled through; very near the end of the 2400 feet length - something catastrophic happened. This story would be dramatically more interesting if I could tell you what that catastrophic incident was - but (spoiler alert) - I can't. Something happened though and they were forced to pull the pipe back out. BUT, after they'd gotten the pipe 1200 feet out of the bore hole; the pipe got 'stuck'. As a result - they were only able to recover 1200 feet of the 2400 feet. So 1200 feet out and stacked and available for inspection....and 1200 feet trapped in a dark, dirty, muddy hole - never to be seen again.
So, how did the DIRAX hold up on the journey? How did the dual layer FBE hold up on the journey? Let's look at a few photos:
What we saw was that the DIRAX outperformed the factory applied coating even though it had been asked to do more than what it was designed for (DIRAX is really designed as a 'one way' coating - meaning the added wear cone / leader strip is designed to offer extra protection but only when installed on the leading edge). So while we do see some light damage (over the mainline coating - not over the bare steel), we see more damage on the dual layer.
In addition, in every spot, no matter the direction it was pulled, the DIRAX served its main purpose - protecting the S1301M epoxy that was installed on the bare steel of the pipe to act as the primary corrosion coating and bonding agent between the bare steel and the DIRAX sleeve.
It isn't often we get access to such an unusual pipeline job where we are able to inspect our product and the condition it is in on the heels of it being put through the absolute ringer. I must say I was pleased, but not surprised by the result.