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ELECTRICAL WORK
<br />Section 16050 - Page 2 is
<br />B. Rigid Steel Conduit:
<br />1. Standard weight, threaded, zinc coated on outside by hot dipping,
<br />sherardizing or metallizing process, with protective finish coating on
<br />outside and inside.
<br />2. Fittings: Threaded type, steel or malleable iron; set screw type or
<br />threadless type, not acceptable.
<br />C. Rigid PVC Conduit.
<br />1. Schedule 40 rigid polyvinyl chloride electrical conduit, listed by UL for
<br />direct underground burial, manufactured from high impact, nonconducting,
<br />selfextinguishing material.
<br />2. Couplings, Adapters, Expansion Fittings: Conform to same requirements
<br />as rigid PVC conduit. Use solvent cement for all PVC joints, as recom-
<br />mended by conduit manufacturer.
<br />3. Bends: Factory made rigid steel conduit bends; PVC conduit bends, not
<br />acceptable.
<br />D. Protective Coating: Metallic raceways in direct contact with earth or fill
<br />of any type, shall be zinc coated rigid steel conduit with corrosion resisting
<br />protective coating, consisting of spirally wrapped pressure sensitive tape
<br />with protective overwrap, or factory applied coating.
<br />1. Tape: Polyethylene or PVC, min thickness of backing material 0.010", min
<br />dielectric strength of 10,000 volts, Johns Manville #E-12 and #VID-10,
<br />Chase #750, Polyken #900, 3M Co., #50, Plymouth #100, or equal.
<br />2. Protective Overwrap: Either 15 lb tar or asphalt saturated felt secured
<br />with tape; or asphalt laminated kraft paper reinforced in both directions,
<br />American Sisal Kraft 4207, Chase X6770, or equal.
<br />3. Application: Clean conduit before applying tape, using totally volatile
<br />solvent so as to leave no oil. Tape and overwrap to be machine applied
<br />using 1/2" min lap. Apply wraps uniformly and tightly, free of voids
<br />and wrinkles.
<br />Where total length of conduit for entire project does not exceed 501,
<br />tape and overwrap may be hand applied.
<br />4. Factory Applied Coating: PVC seamless jacket, min thickness 0.020",
<br />firmly bonded to galvanized surface of rigid steel conduit, Occidental
<br />Coating Co., "OCCAL-20", Plastic Applicators "KorKap", Pittsburgh
<br />Standard Conduit Co "PlastiBond", or equal. Where standard 90° and 45°
<br />bends are required use PVC jacketed factory made bends. Where field
<br />bends are required, use standard bender of next larger size, and protect
<br />section of conduit to be bent with kraft paper wrap.
<br />5. Field Joints.
<br />a. For Wrapped Conduit: Cover field joints and bends with 2 layers of
<br />tape and one layer of overwrap, applied with 1/2" min lap and extend-
<br />ing at least 6" over adjacent covering. Tape and overwrap as
<br />specified above, except tape 2" wide max. Tape overwrap in place.
<br />b. For Factory Coated Conduit: Use factory coated, rigid steel fittings
<br />with overlapping PVC sleeves, 0.040" min thickness. Sleeves shall
<br />extend beyond end of fitting min distance equal to nominal dia of
<br />conduit, and shall fit tightly over conduit coating to form a water-
<br />tight joint.
<br />021387:cw MAR 702
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