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Wheatland TUBE COMPANY DIVISION OF JOHN MANEELY COMPANY |
Fire and Casualty Hazards
Each contractor shall submit proof that the conduit proposed under
this specification conforms to UL6. The UL listing mark may be accepted as evidence that
the conduit conforms to this requirement.
Marking
Conduit shall be permanently marked in accordance with ANSI C80.1
and UL6.
Workmanship
All threaded portions of conduit shall be clean and undamaged.
Plastic thread protectors shall be furnished on all exposed conduit threads. The exterior
zinc coating, and all other protective coatings, including the interior coating and thread
coating, shall completely and uniformly cover the metal substrate.
AMERICAN NATIONAL STANDARD INSTITUTE SPECIFICATION FOR
ZINC-COATED RIGID STEEL CONDUIT
The ANSI Specification C80.1 is very precise and explicit in setting
standards for rigid steel conduit. Wheatland's rigid steel conduit matches these standards
in every way. It meets the general requirements of having an accurate circular cross
section, a uniform wall thickness, a defect-free interior surface and continuously welded
seams. It is thoroughly cleaned before coating so the protective coating adheres well and
is smooth. The exterior surface is thoroughly and evenly coated with metallic zinc applied
directly to the steel so that metal-to-metal contact and galvanic protection against
corrosion are provided. The interior sur-
face is protected by zinc for corrosion resistance.
DETAILED REQUIREMENTS
Some of the pertinent detailed requirements of Specification C80.1
are interpreted and summarized below for your reference and assurance that Wheatland Rigid
Steel Conduit is produced to precise standards.
Zinc Coating
The zinc content of the coating on the outside surface shall be
equivalent to a minimum thickness of 0.0008 inches.
Threading and Chamfering
Each length of conduit shall be threaded on both ends, and each end
shall be chamfered or otherwise treated to remove burrs and sharp edges. If threads are
cut after the zinc coating has been applied, the threads shall be treated with a
protective coating to prevent corrosion before installation. This treatment shall not
impair electrical continuity through couplings or fittings after installation.
Identification
Each length of conduit shall be identified with the manufacturer's
name and trade mark and the words "Rigid Steel Conduit."
Threads
The number of threads per inch and the length of the threaded
portion at each end of each length conduit shall be as shown in the accompanying table and
shall conform to American Standard Pipe Threads. The perfect thread shall be tapered for
its entire length, and the taper shall be 3/4 in/ft.
Dimensions of Threads for Rigid Steel Conduit, Zinc Coated
| Nominal
or Trade size of conduit (inches) |
Threads
per inch |
Pitch Diameter
at End of Thread Eº |
Length
of Thread (inches) |
| Taper ¾ inch
per Foot |
Effective L2 |
Overall L4 |
| 3/8 |
18 |
0.6120 |
0.41 |
0.60 |
| ½ |
14 |
0.7584 |
0.53 |
0.78 |
| ¾ |
14 |
0.9677 |
0.55 |
0.79 |
| 1 |
11½ |
1.2136 |
0.68 |
0.98 |
| 1¼ |
11½ |
1.5571 |
0.71 |
1.01 |
| 1½ |
11½ |
1.7961 |
0.72 |
1.03 |
| 2 |
11½ |
2.2690 |
0.76 |
1.06 |
| 2½ |
8 |
2.7195 |
1.14 |
1.57 |
| 3 |
8 |
3.3406 |
1.20 |
1.63 |
| 3½ |
8 |
3.8375 |
1.25 |
1.68 |
| 4 |
8 |
4.3344 |
1.30 |
1.73 |
| 5 |
8 |
5.3907 |
1.41 |
1.84 |
| 6 |
8 |
6.4461 |
1.51 |
1.95 |
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