Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
(OP)
I am not clear on which type of dies to use threading 1/2" conduit for a Class 1, Div 1 installation. My understanding is that conduit threads are "straight threads" for mechanical construction, and that pipe threads are tapered for sealing. The NEC 346-8 refers to ANSI B.1.20.1. Is there something I missed in the NEC or ANSI B.1.20.1 that states which treads should be used?






RE: Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
Don
RE: Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
99NEC500-3. General.
(d) Threaded Conduit. All threaded conduit referred to herein shall be threaded with an NPT standard conduit cutting die that provides 3⁄4-in. taper per foot. Such conduit shall be made wrenchtight to prevent sparking when fault current flows through the conduit system, and ensure the explosionproof or dust-ignitionproof integrity of the conduit system where applicable.
RE: Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
If you are preparing a spec for conduit, please do add that an anti-seize compound be applied to all threads prior to final assembly.
cheers.
a.
RE: Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
Don
RE: Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
RE: Are conduit or pipe threads used in Class 1, Div 1 Enviroments?
http://www.alliedtube.com/grc.pdf Column 1 calls out the ¾-inch-per-foot taper and ANSI B.1.20.1. It’s very likely that listed galvanized-steel and aluminum conduit and IMC have the same characteristics. The details would probably be described in the corresponding UL standard.