(A) Steel pipe for aerial creek crossings or boring installations (without encasement and carrier pipe) shall be high strength steel, spiral welded or smooth-wall seamless manufactured in accordance with A.S.T.M. A139 and A283 and consisting of grade B steel with a minimum yield strength of 35,000 psi. On eight- and ten-inch pipe, the minimum wall thickness shall be 0.375 inches.
(B) The outside of the pipe shall have one coat of zinc chromate primer conforming to Federal Specification TT-86a and afterwards painted with a compatible black paint.
(C) Pipe ends shall be right-angled and shall be compatible to receive a dresser style 62 - type I or approved equal mechanical transition coupler.
(D) Steel encasement pipe shall be spiral welded or smooth-wall seamless, consisting of grade B steel with a minimum yield strength of 35,000 psi and manufactured in accordance with A.S.T.M. A139 and A283.
(E) The pipe thickness shall be as required by the encroachment agreement obtained from the controlling agency, but in no case be less than 0.250 inches and the ends shall be beveled and prepared for field welding at the circumferential joints. Thicker encasement pipe may be required by the State Department of Transportation, Railroads or other agencies.
(F) The pipe shall be coated inside and outside, in accordance with AWWA C-203 or the State Department of Transportation or the American Railway Engineering Associations specifications. All encasement pipe must be approved by the appropriate controlling agency (i.e., NCDOT, RR and the like) prior to ordering the materials.
(G) If the encasement pipe is used to carry a sewer main, then a vent pipe shall be installed. The vent pipe shall be made from A.S.T.M. A139 and A283, grade B steel, with a minimum yield strength of 35,000 psi and coated as described above. The vent pipe location shall be approved by the appropriate agency prior to installation.
(H) All carrier piping shall be slip joint ductile iron and the minimum inside diameter casing shall be eight inches greater than the outside dimension of the carrier pipe as follows:
Carrier Pipe Inside Diameter | Steel Casing Pipe Minimum Inside Diameter |
4-inch | 12-inch |
6-inch | 12-inch |
8-inch | 16-inch |
12-inch | 24-inch |
16-inch | 30-inch |
(Ord. passed 6-21-2011)