Soaking II: Safety First
Dear Greatest of Soakers,
It seems odd to me that for one who spends so much time soaking herself, that soaking cables is anathema to your firm’s culture. When is it appropriate to soak a No.2 compressed URD cable? If I do soak, for how long should I soak?
Geometrically constrained,
Alaskan Amber
I provided a first installment of my thoughtful answer to your question in “Soaking: Diminishing Returns I.” In that first post, I drove a stake into the heart of the myth that Novinium never soaks, and I provided the background to explain why it is seldom necessary to do so. In this second post I will explain why soaking is so very dangerous when performed the old way.
I could explain the safety issue in my own pithy way, but instead I copy below the words of Messrs. Stagi and Steele of UTILX Corporation. They were granted U.S. Patent 7,704,087 about one year ago. The patent is titled, “Check Valve for Charge Tanks.” They have undoubtedly experienced the dangers posed by soaking. I assume those experiences motivated their invention. To wit (beginning on column 1, line 45) …
The fluid is commonly injected into underground cables from a fluid feed line, which is connected to a fluid feed tank, at the injection termination. When fluid is injected into the cables at the injection port of the injection terminations, it is assumed that the fluid flow is only in one direction, flowing from the feed tank to the cable. However, as the cable fills and the fluid system begins to stabilize, temperature changes that occur inside the cable or outside in the environment around the feed tank can cause the pressure of the system to fluctuate. The pressure fluctuations can lead to instances where the pressure inside of the injection elbow is greater than the pressure inside of the fluid feed tank. At this point, fluid flow would reverse, moving from the injection elbow back into the fluid feed tank.
The fluid that travels in the reverse direction, out of the injection elbow, carries contaminants from the cable to the feed tank. These contaminants can be conductive or semiconductive, effectively reducing the insulating value of the remediation fluid in the fluid feed line that separates the energized cable from the feed tank and a conductive pathway can be formed.
I don’t always agree with the gentlemen from UTILX. Lacking an amphibian influence, they seem to me to be prone to error, but this time they have eloquently defined the issue. Fluid can flow backward through the feed tubing during the soak period. An energized tube and feed tank may flash to ground, may start a fire or worse yet an explosion, and, if anybody is nearby, the unfortunate event might injure or even kill them! At Novinium we are not willing to take those kinds of risks. I hope my colleagues at UTILX implement their ‘087 invention before there are any new events.
As mentioned in my last post, Novinium can and does greatly mitigate these risks in live-front applications with a piece of proprietary technology called an HVFI or high-voltage fluidic-interface. Click here to view a HVFI test report, which includes a detailed description of how it works.
If you really, really want to soak in dead-front applications, my mechanical engineers and I will develop a system that is much safer. Of course, using non-flammable Novinium fluids helps a lot, but we can do even better. When you see how a frog solves this problem, you will see elegance embodied. Stand by for more on this subject.
Safety First,
Thermo
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