nipples and supports

[apparatusnine]

so my question is nipples and supports. chapter nine states that a nipple is a conduit or tubing that is less then 24 inches. does it need supports, straps?

ie, at work.

so im at a T.I. remodel. panel before remodel had 8 one inchers going throw the floor down to walker duct. my job wus to install a gutter and intercept all the one inchers from the walker duct to the panel. i came out the gutter with 8 one inchers back to the panel. between the gutter and the panel wus 15 inches. so, thos are nipples. do they need straps?

i read it as they dont, but others on the job said yes per 358.30(a). i put up shallow strut and strut straps and called it good. but it wus just the topic of the day.

 

[infinity]

Since you cited Article 358 I'll assume that the nipples are EMT. They can up to 18" long and unsupported if there are no concentric or eccentric KO's and there is no coupling in the EMT. 358.30(C). This is a stupid rule IMO.

 

[jwjrw]

Since you cited Article 358 I'll assume that the nipples are EMT. They can up to 18" long and unsupported if there are no concentric or eccentric KO's and there is no coupling in the EMT. 358.30(C). This is a stupid rule IMO.

I agree its a stupid rule.

 

[don_resqcapt19]

While I don't like the rule as it has been commonly accepted to permit 3' unsupported before this rule appeared in the code, but without the rule all conduit nipples must be supported as there is no exception to the support rule and there is nothing in the code that says a conduit termination can be used as a conduit support. The easiest fix for this rule problem in the code would be to permit the conduit termination to serve as a support.

 

[George Stolz]

IIRC, this allowance's status is in peril in the 2011 NEC - so if it continues, we'll lose the right to skip strapping EMT that is 3' or less in length. I don't understand the animosity toward the rule, myself.

 

[infinity]

The rule should be 3' for the nipple and allow the connectors to provide the support just like they do when the strap is 3' away from a box. I can strap the conduit 3' from the box, have X number of couplings within that 3' and also have concentric or eccentric KO's, but if I use an 18" nipple I can't use a coupling or have eccentric or concentric KO's. The rule doesn't make sense.

 

[don_resqcapt19]

IIRC, this allowance's status is in peril in the 2011 NEC - so if it continues, we'll lose the right to skip strapping EMT that is 3' or less in length. I don't understand the animosity toward the rule, myself.

Prior to the 2008 code, the code required all conduits to be supported. There was no exception for short nipples, however it was common for the inspectors to permit up to 3' without any supports other than the conduit terminations. A proposal for 2008 would have put that 3' rule into the code, but the CMP reduced it to 18". It appears that the CMP wants to go back to the old way where the inspectors permitted a 3' nipple to be installed without any supports, but they don't want to put that rule into the code.