multiple conduit seals

[Jon1980]

Is there a formula for figuring out how much fiber to use on each seal. I know that each seal comes with specs on what is needed for that particular size. But I have a mixture of 4", 3", 2", 1 1/2", 1", and 3/4 and need to order fiber and chico. All the seals are eyx's or the next size up. I have never had to fill this many seals before and I've come up short on fiber before.

Second is it ok to use Duct seal to pack the larger seals?

 

[rbalex]

Typically, each manufacturer can supply an estimate of sealing fiber and compound per seal fitting since they must be listed together [See 501.15(C)(1)]. For example. (See second page)

Ductseal is not acceptable where the seals are required to be explosionproof. Division 2 / unclassified boundary seals are not required to be exposionproof [Section 501.15(B)(2)]; whether ductseal is acceptable in such cases is a subject left to the AHJ. Personally, I would accept it since the vast majority of such boundary seals aren't necessary in the first place [See all four Section 501.15(B)(2) Exceptions].

 

[petersonra]

I don't do all that much of it these days, but I always just bought enough that I was comfortable I would not run out. My theory always was the stuff was not all that expensive to begin with and if there is some left over, I just did not care.

I am one of those guys that has the seals installed but not poured on our equipment. I have a big red tag put on it saying it has to be field poured. It is almost but not quite impossible to replace or add a wire once the seal is poured and I would just as soon not pour them until absolutely necessary.