For some 50 years KWH Pipe has been a leader in the design, development, manufacture and engineering support of polyethylene piping systems. Our capabilities in large diameter and solid wall High Density Polyethylene (HDPE) pipe and fittings have made the company distinctive in the world of plastic pipe. Industry Firsts Extensive R&D led KWH Pipe, in the 1960’s, to produce 16" diameter polyethylene pipe at a time when many considered large diameter polyethylene pipes a technical impossibility. In 1964, KWH engineers introduced a 24" pipe, which was then the largest in the world, and at a time when a 6" diameter plastic pipe was considered a large size. Today KWH Pipe produces 63" HDPE solid wall Sclairpipe® pipe and 120" lightweight, HDPE profile wall Weholite® pipe plus WehoGas piping for natural gas transmission. The company has also developed and patented a unique welding machine designed specifically for joining pipes using thermal fusion to assure leak-tight joints. In 1968 KWH Pipe built its first North American pipe plant making it the continent’s first manufacturer of large diameter, HDPE pipe. Today, KWH Pipe supplies Canada, the United States, the Caribbean, Central and South America from two North American plants.