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#40870 - 08/08/04 06:26 PM Are compression coupling over-rated?  
Peter  Offline
Member
Joined: Jun 2004
Posts: 92
San Diego
I am getting tired of comression fittings. When I tighten one, it graps the preceding conduit with an offset in it and twists it out of alignment. Sometimes the pipes pull out. Wrenches don't fit very well on them. They aren't really water proof.
I know they cost more which may be why they are specified but are they really any better than set screw connectors?
~Peter


Work Gear for Electricians and the Trades

#40871 - 08/08/04 10:10 PM Re: Are compression coupling over-rated?  
twh  Offline
Member
Joined: Mar 2004
Posts: 915
Regina, Sask.
Something like the "Rainboot" connectors and couplings for rigid would be nice.


#40872 - 08/09/04 04:10 PM Re: Are compression coupling over-rated?  
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
If they are being specified for indoor work, keep in mind that some architects & engineers get a % of the toal job cost.

Some feel that compression fittings make for better equipment ground continuity, but I've never seen one bit of scientific evidence to support this.

If physical strength is an issue here, perhaps RMC should be installed instead of EMT.

Tom


Few things are harder to put up with than the annoyance of a good example.

#40873 - 08/09/04 04:21 PM Re: Are compression coupling over-rated?  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
Peter it all depends on the quality of the fittings.

The ones I get as part of a large negotiated purchase are junk, I could tighten them up as much as possible and they are still loose. Usually they have a "Made in Mexico" label

On the other hand when I do T&M jobs and order small quantities I get top quality parts. Compression fittings with deep throats and glands that grab.

I guess it all about what your willing to pay for.

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#40874 - 08/09/04 04:47 PM Re: Are compression coupling over-rated?  
electricman2  Offline
Member
Joined: Nov 2003
Posts: 269
Thomasville, NC USA
IMO a compression connector properly used is much better than the set screw type. It can be re-tightened if necessary. Try that with a set screw. Just my 2ยข

[This message has been edited by electricman2 (edited 08-09-2004).]


John

#40875 - 08/09/04 07:20 PM Re: Are compression coupling over-rated?  
golf junkie  Offline
Member
Joined: Apr 2001
Posts: 507
York, NE
More and more of our commercial work is spec'd with all steel compression fittings. I always assumed it was for bonding continuity, but it certainly does drive the cost up.


#40876 - 08/09/04 10:14 PM Re: Are compression coupling over-rated?  
Active 1  Offline
Member
Joined: Feb 2003
Posts: 687
Grayslake IL, USA
I found on some cast ridgid copression in the 1 1/4-2" range the ring inside is too big. If I use large adjustable wrinches and get it as tight as possable the pipes are not tight, will spin, and may pull apart. If I take it apart and clip just a hair off both ends of the sealing ring it works great. When I put the pipes back together BY HAND ONLY I can't even twist them let alone pull them apart. Of coarse I crank it down still. A quality issue I guess. I don't know what it does when the rain comes but keeping the pipes together is priority 1.

Tom


#40877 - 08/10/04 05:29 PM Re: Are compression coupling over-rated?  
Joey D  Offline
Member
Joined: Oct 2003
Posts: 259
Arlington MA U.S.
I did a horse barn with comp fittings and they were fine. I use steel fitings for all emt so maybe thats the difference.



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