water tight couplings

[don_resqcapt19]

who is going to make more money by requiring tapered threads?

Everyone. Both the material and labor costs will go up.
25 or more years ago, the CEC (Canadian Electrical Code) required conduit couplings with tapered threads. The steel tube institute lobbied the CEC to get a change to permit the use of straight thread couplings. In talking with a rep from Allied Tube, after that change, she told me that they got a lot of complaints about the conduit leaking when they switched to straight thread couplings.

 

[K8MHZ]

This has been a sore spot with me, too.

First, I don't see 314.15 as being achievable. For EMT, there is no way to place or equip a coupling that will prevent moisture from entering or accumulating. 'Prevent' means under all conditions.

Second, 314.15 only requires the above to prevent moisture from entering boxes, fittings or conduit bodies. It does not mention raceways.

Third, 314.15 does not exempt any type of fitting. There is no exception that allows RMC to not have the same fitting requirement as EMT. Instead, there is just a reference for EMT in the EMT section, but not one for RMC in the RMC section. I don't see that as an exception.

And when has using standard compression fittings in wet locations so long as the conductors are rated for wet locations ever been a problem?

It makes no sense to require essentially waterproof conduit connections and then not require the ends to be sealed. Especially when they come up into an outside panel. Those most definitely are not waterproof and are not made to prevent moisture from entering.

 

[kwired]

Everyone. Both the material and labor costs will go up.
25 or more years ago, the CEC (Canadian Electrical Code) required conduit couplings with tapered threads. The steel tube institute lobbied the CEC to get a change to permit the use of straight thread couplings. In talking with a rep from Allied Tube, after that change, she told me that they got a lot of complaints about the conduit leaking when they switched to straight thread couplings.

Why would the steel tube institue lobby for less cost that can be passed on to their buyers and more profits can be made?

If this were an issue that would make cost of steel vs cost of non steel products a determining factor in consumer decisions I could understand that.

 

[don_resqcapt19]

Why would the steel tube institue lobby for less cost that can be passed on to their buyers and more profits can be made? ...

I am not sure that the cost to buy rigid conduit went down after the switch from tapered to straight thread couplings was made.

 

[kwired]

I am not sure that the cost to buy rigid conduit went down after the switch from tapered to straight thread couplings was made.

why would they cut cost? if it cost less to produce and you charge the same as before - there is more profit, there would have to be competition or supply/demand issues to drive the cost down.

and


when did that happen? I have taken apart some RMC runs that are likely 40-50 years old and seem to recall the couplings were all straight threaded.