Rigid Conduit vs Regular Iron pipe

You can bend conduit with an inexpensive tool. Conduit is much lighter and cheaper than pipe.

Dan

I've never seen rigid bent, only light & intermediate. Rigid is heavy & threaded. It uses preformed sweeps & boxes to make turns. AFAIK

Bob

Conduit is thin wall material. It cant be threaded with any suitability. Its not designed to carry anything other than wire.

Pipe is thick wall and is designed to be threaded and then threaded into pipe fixtures...

Its capable of carrying significant pressures

Gunner

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie

Only if you dont have a pipe bender for rigid. I have several differnet types of hand benders for rigid.

Gunner

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie

There are three standard weights for electrical conduit -- EMT ("thinwall"), IMC (intermediate metal conduit) and GRC (galvanized rigid conduit). Partial table of standard dimensions per relevant ANSI spec's...

GRC

MIN. WGT. /100 FOOT O.D. I.D. THICKNESS SIZE IN LBS. INCHES INCHES INCHES

1/2" 79 0.840 0.632 0.104 3/4" 105 1.050 0.836 0.107 1" 153 1.315 1.063 0.126 1 1/4" 201 1.660 1.394 0.133 1 1/2" 249 1.900 1.624 0.138 2" 332 2.375 2.083 0.146

EMT

1/2" 29 0.706 0.622 0.042 3/4" 44 0.922 0.824 0.049 1" 65 1.163 1.049 0.057 1 1/4" 96 1.510 1.380 0.065 1 1/2" 111 1.740 1.610 0.065 2" 141 2.197 2.067 0.065

Steel pipe Sch Sch Sch Sch OD 5 10 40 80

1/2 0.840 0.065 0.083 0.109 0.147 3/4 1.050 0.065 0.083 0.113 0.154 1 1.315 0.065 0.190 0.133 0.179 1 1/4 1.660 0.065 0.109 0.140 0.140 1 1/2 1.900 0.065 0.109 0.145 0.200 2 2.375 0.065 0.109 0.154 0.218

As can be seen, GRC is roughly same weight as, but still slightly lighter (thinner wall) than Sch 40 pipe but they have same OD

Thanks for your informative reply. What are the thread specs? Std NPT or something else. The couplings I have seen for GRC seen to be non tapered. Is GRC meant to be liquid tight to prevent moisture entering? Thanks

CP

You are thinking EMT - electro-metalic tubing - not Rigid Conduit. Rigid conduit is thick, and is threaded for EVERY use.

1" rigid conduit is .126 inch wall. The thread is generally a straight thread instead of a tapered thread on pipe. 1 inch Sched 40 iron pipe is .130" wall thickness. 2 inch rigid is .146 inch wall thickness, while sched 40 iron is .150 nominal thickness

Rigid steel conduit can be galvanized (in and out) electro galvanised (outer only) with organic coated interior, or organic coated in and out - and Rigid conduit can also be aluminum or stainless steel or red brass.

RMC has a smoother interior than pipe - it is a rolled, electrically welded seam tubing with uniform wall thickness and a defect free interior surface - required for pulling wire.

Black Iron Pipe is made from ductile iron - not steel (generally speaking).

Rigid is fun to bend. You definately need more thean a three foot handle on the bender. Have you ever used rigid aluminum conduit?

GRC uses a NPS thread, not NPT (National Pipe Straight) not (National Pipe Tapered)

A recently published NEC book will tell you about all of the trade metallic and NMC conduit. You should be able to find one at any hardware store.

I think this misunderstanding has been repeated here several times. The threads on the ends of rigid conduit are tapered pipe threads. Female threads on conduit fittings are often straight threads.

Per Wheatland: "Wheatland?s Galvanized steel Rigid Metal Conduit (RMC) is manufactured in accordance with the latest specifications and standards of ANSI® C80.1, UL-6, and federal specification WW-C-581. The pitch of RMC threads conforms to the American National Standard for Pipe Threads, General Purpose (Inch), ANSI/ASME B1.20.1. The taper of threads is 3/4 inch per foot (1 in 16). "

From NFPA 70 - 2008: "344.28 Reaming and Threading. All cut ends shall be reamed or otherwise finished to remove rough edges. Where conduit is threaded in the field, a standard cutting die with a 1 in 16taper (3/4-in. taper per foot) shall be used. FPN: See ANSI/ASME B.1.20.1-1983, Standard for Pipe Threads, General Purpose (Inch)."

Thanks. This is the info I was looking for.

CP

Ive heard of aluminum conduit..but give its properties...Id stay way way away from it.

I did help install a hydrogen furnace (50 feet long) using stainless steel 1" pipe some years ago though. Some really odd pipe dope in that project.

Gunner

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie

You are absolutely correct. I glossed over the first "rigid" My appologies indeed.

A definate Brain Fart on my part.

Gunner

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie

They used it in a juice processing plant near here, along with a lot of stainless pipes for the juice. I ended up with some leftover 3/4" aluminum conduit that had surface damage.

Whats it like to bend and how is the surface treated? Sounds like White Fur country. That nasty white fur that grows on unanodized aluminum as it eats its way in.....

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie

Iron pipe is pressure rated. I did see anyone stae that.

Remove 333 to reply

The stuff is soft compared to iron. It can be bent by hand, and has anodized surface. I had about 40 to 45 pieces, till my dad found it in my stockpile and bent it into a pile of scrap to sell for the aluminum. I had told him he could use any of the EMT scraps he wanted, but to leave all the 10' pieces alone. He wasted about $1000 worth of pipe & conduit.

I only manged to find a few pieces he missed. He would step on it in the middle and fold it in half. It brought about 15% of the price it would have sold for as conduit.

OUUUCHH!!!!!

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie