oranjeep
Member
- Location
- Pennsylvania
2002 NEC, Article 250.70
"...listed pressure conectors, listed clamps, or other listed means."
I am a consultant trying to save the client money
on grounding and bonding a pneumatic conveying system of zinc galvanized stainless steel tubing that conveys pharmeceutical waste dust and debris in a R&D facility. The tubing, all together laid end to end, is probably a mile long, and has heat shrinked rubber couplings used as fittings to connect one tube to the next. There are hundreds of these couplings, and the tubing ranges from 2.5" diameter to 4".
The tubing can be penetrated to bond a wire to it,but we would rather not mess with the integrity of the system-we cannot afford any leaks (which is why they used the heak shrink) Also, any protrusions on the inside of the pipe are unacceptable.
Because of the sensitivity of the material inside the pipes, exothermic or regular welding is not an option either, due to heating of the pipe. I have already discussed this with the client.
The only option we have is clamps. There are several kinds of clamps.
Refering to the NEC, which clamps are "listed?"
Where are they listed? I know we can use the standarf water pipe clamp, but at ~$40 a clamp, and the weight of hundreds of these clamps,
and the obtrussivenes of them, I would rather try to find another way of doing this while still satisfying the code.
Can we use worm clamps, since all we are dealing with here is static electricity dissipation?
How about BURNDY abjustable ground straps? (FCI markets them)?
"...listed pressure conectors, listed clamps, or other listed means."
I am a consultant trying to save the client money
on grounding and bonding a pneumatic conveying system of zinc galvanized stainless steel tubing that conveys pharmeceutical waste dust and debris in a R&D facility. The tubing, all together laid end to end, is probably a mile long, and has heat shrinked rubber couplings used as fittings to connect one tube to the next. There are hundreds of these couplings, and the tubing ranges from 2.5" diameter to 4".
The tubing can be penetrated to bond a wire to it,but we would rather not mess with the integrity of the system-we cannot afford any leaks (which is why they used the heak shrink) Also, any protrusions on the inside of the pipe are unacceptable.
Because of the sensitivity of the material inside the pipes, exothermic or regular welding is not an option either, due to heating of the pipe. I have already discussed this with the client.
The only option we have is clamps. There are several kinds of clamps.
Refering to the NEC, which clamps are "listed?"
Where are they listed? I know we can use the standarf water pipe clamp, but at ~$40 a clamp, and the weight of hundreds of these clamps,
and the obtrussivenes of them, I would rather try to find another way of doing this while still satisfying the code.
Can we use worm clamps, since all we are dealing with here is static electricity dissipation?
How about BURNDY abjustable ground straps? (FCI markets them)?