Rigid galvanized coupling to liquid tight flex connections

ramsy said:
See picture with O-Ring, or sealing locknut, for wet location approval.
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What product is that? Is that an add-on accessory or is it fitting that comes with it? Whatever it is it's horrible, throw it in the garbage. Maybe someday UL will understand that rubber seals need to be in machined groove so they don't get destroyed and the joint can be thoroughly tightened. I thought humanity figured that out like in the industrial revolution 🙄
 
electrofelon said:
What product is that? Is that an add-on accessory or is it fitting that comes with it? Whatever it is it's horrible, throw it in the garbage.
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O-Rings are not required to be listed. Inspectors can't complain, and neither can you.
 
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ramsy said:
O-Rings are not required to be listed. Inspectors can't complain, and neither can you.
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believe me, I'm the last person in the world who you would see being a listing cop, butnfor the purposes of discussion there is 350.42:

Couplings and Connectors. Only fittings listed for use with LFMC shall be used. Angle connectors shall not be concealed. Straight LFMC fittings shall be permitted for direct burial where marked.

So I guess you can put an O-ring on, but isnt it kind a moot point because you cant (technically) use the LFMC connector with a RGS coupling?
 
electrofelon said:
isnt it kind a moot point because you cant (technically) use the LFMC connector with a RGS coupling?
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If LFMC connector to RGS coupling are both straight threads, whats the problem in dry locations?

In wet locations the O-Ring included with LFMC connectors is all you need.
Outlet Bushings and Fittings (QCRV)
..
Sealing Gaskets (Washers) — .. Sealing gaskets may also be used with certified wet location or liquid-tight fittings where so marked on the fitting carton.
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electrofelon said:
That still doesn't explain it.
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You would have to dig back about 40 years when the requirements in Canada were changed from requiring tapered threaded couplings to requiring straight thread couplings. I don't think rigid conduit in the US ever used tapered thread couplings.
I think taper thread couplings should be the requirement as the straight thread couplings in a vertical installation let water run into the conduit.
 
ramsy said:
Or buy a fancy female adapter

Liquid Tight Connector with female threads

Liquidtight connector with female threads connects the flexible conduits to male threads. PT, G, PF, PG, METRIC, NPT
delikon.com
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Remove the RGS coupling and use this Listed LFMC connector for connection with the Appleton ST connector mentioned above. Both have tapered NPT threads.


Sent from my iPhone using Tapatalk
 
ramsy said:
If LFMC connector to RGS coupling are both straight threads, whats the problem in dry locations?
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i think the issue is because broadly, the fitting has not been investigated for use in hubs, they are only tested to mount to an enclosure with a locknut. Whether it is a wet location or not doesnt have anything to do with the listing issue. The non weathertight seal is just an idea being thrown out there and has no basis on any listing document or instructions that I am aware of.
 
wwhitney said:
Do you have an LFMC fitting with tapered male threads on it? Then you can use it with a straight coupling.

But most "connectors" for EMT, LFMC, etc use straight threads and are only for connecting to a hole in sheet material, not female threads.

Cheers, Wayne
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This simply a case where the listing standard needs to match up with the real world. In industrial work, I bet 95%+ of the liquid tight flexible metal conduit connectors are threaded into fittings having female threads. I know for sure that was the case with my projects...had boxes of 1/2" locknuts that came off the connector because we never used them.

I am not aware of any reported issues ...just a use outside of the evaluation of the product.
 
ramsy said:
See picture with O-Ring, or sealing locknut, for wet location approval.
Click to expand...
That O ring is to seal on a flat surface when the connector is attached to an enclosure. It is not intended to be used with a coupling or other fitting having female threads.
 
don_resqcapt19 said:
This simply a case where the listing standard needs to match up with the real world. In industrial work, I bet 95%+ of the liquid tight flexible metal conduit connectors are threaded into fittings having female threads. I know for sure that was the case with my projects...had boxes of 1/2" locknuts that came off the connector because we never used them.

I am not aware of any reported issues ...just a use outside of the evaluation of the product.
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And I believe (unless someone can show me otherwise) the water entry and insufficient bonding theories have no basis in fact. In other words, the fittings didnt "fail" these tests and/or UL didnt say "you cant thread a straight into a taper because XYZ" or anything. They were just never investigated, not really sure why. Probably it would have been more testing fees and no one wanted to pay it.
 
don_resqcapt19 said:
taper thread couplings should be the requirement as the straight thread couplings in a vertical installation let water run into the conduit.
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Thanks for sharing that straight (parallel) thread couplings wont seal with NPT conduit nipples.

Here's more info on other combinations:

Straight-thread joints seal better than tapered-thread joints
georgia.swagelok.com

| Swagelok

georgia.swagelok.com georgia.swagelok.com
TAPERED VERSUS PARALLEL THREADS

Tapered Pipe Threads ..Tapered pipe threads work by interference fit and will require a sealant to make a leak tight seal. A good sealant is always required

Parallel Pipe Threads ..A gasket (all metal or composite) or O-ring is normally used to seal parallel pipe thread connections. No Teflon tape or sealant is utilized on these threads.
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electrofelon said:
They were just never investigated, not really sure why. Probably it would have been more testing fees and no one wanted to pay it.
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I agree. And was fine that way for years with standard compression fittings being used in wet locations until someone came up with a "raintight fitting" that actually had little to no improvement over what we already had but needed it to be listed differently so they can sell more of them.

A little surprising similar hasn't happened with these LT flex fittings. Not only do people couple them to another raceway with rigid couplings but also put them into reducing bushings, threaded hubs on conduit bodies, boxes, some motor terminal boxes (pecker heads), etc. some of those items are straight thread some are tapered thread. Not many inspectors pay much attention to details on this though, some might even be aware of the listing complexities yet still ignore it in most these situations as they are practical and been there themselves. The ones that have little or no installation experience or were maybe always given a hard time by some inspector when they were an installer are the ones that tend to make a big deal over such things just to take out their prior frustration on others.
 
electrofelon said:
And I believe (unless someone can show me otherwise) the water entry and insufficient bonding theories have no basis in fact. In other words, the fittings didnt "fail" these tests and/or UL didnt say "you cant thread a straight into a taper because XYZ" or anything. They were just never investigated, not really sure why. Probably it would have been more testing fees and no one wanted to pay it.
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Because that testing is not required by the product standard. There is nothing in the standard to test to, so the standard would have to be changed to include such testing.
 
kwired said:
I agree. And was fine that way for years with standard compression fittings being used in wet locations until someone came up with a "raintight fitting" that actually had little to no improvement over what we already had but needed it to be listed differently so they can sell more of them.

A little surprising similar hasn't happened with these LT flex fittings. Not only do people couple them to another raceway with rigid couplings but also put them into reducing bushings, threaded hubs on conduit bodies, boxes, some motor terminal boxes (pecker heads), etc. some of those items are straight thread some are tapered thread. Not many inspectors pay much attention to details on this though, some might even be aware of the listing complexities yet still ignore it in most these situations as they are practical and been there themselves. The ones that have little or no installation experience or were maybe always given a hard time by some inspector when they were an installer are the ones that tend to make a big deal over such things just to take out their prior frustration on others.
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Pretty much all of the LFMC connectors used on industrial projects are threaded into one of those.
 
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