District News Articles

  2. Platte Canyon owns water mains made of various materials; cast iron, ductile iron, asbestos-cement, and PVC (polyvinyl chloride). Part of the District’s water main inventory consists of spiral-welded steel pipe.
    Steel water main repairs are conducted much differently than repairs on other pipe types. The steel pipe is encased in a tar-based coating. This protects the steel from soil-contact corrosion. Typically on the District’s water mains made of the other materials a repair clamp (compression band) can be placed over a failure for a quick and inexpensive repair. This is not the case when dealing with steel water mains. Steel mains cannot accept a repair clamp so, typically repairs require welding to correct a failure.
    The District was confronted with such a repair on August 8, 2013 on Sheridan Blvd. at Hinsdale Dr. A corrosion failure was discovered at the bottom of the 18-inch diameter pipe next to a coupling. The only way to repair it was to cut off the coupling and weld on a strap of metal to create a continuous piece of pipe. This requires an experienced welder to form the metal repair band and secure it in place for a leak-free repair.
    The final step in the repair process is to restore the coating to protect the steel surface. A primer is applied over the entire exposed area then a 30mil adhesive-based tar tape is applied overlapping on each revolution.