Why use NEMA G10 Insulation kits?

[Gorpomon]

Hi,

What is the reason to use NEMA G10 gaskets for pipe insulation? They are quite common in the water industry, especially at larger sizes, however I can't see why they need to be used?

Their dielectric strength is high (530 V/mil) however I doubt a pipe has 66,250V go through it (530V * 125mil, 1/8"=125mil). It seems even basic red rubber gaskets at 280V/mil provide more than enough electrical insulation.

Please if anyone can provide feedback I would really appreciate it.

 

[BigInch]

after you put 20,000 lbs compression on that 1/8th inch, what thickness have you got left, not to mention what it would be with red rubber.

 

[cvg]

If I'm not mistaken, it is not uncommon for lightening to travel for some distance through the ground, especially if it manages to travel along a pipeline. Given that the maximum voltage by several estimates is somewhere between 10MV and 100MV with an average current of 30 kA and power output in the vicinity of 1 terrawatt, I think it might be prudent to provide something better than rubber for the gaskets.

 

[Gorpomon]

In the case of lightning numbers you cited, wouldn't the G10 material even be inadequate?