Krah USA

Krah USA, based in Prineville, Oregon, manufactures large-diameter custom HDPE pipe systems using proprietary helical extrusion winding technology. As the largest custom HDPE pipe manufacturer in the United States, Krah USA produces pipes from 100% virgin, pre-compounded HDPE resin — explicitly avoiding recycled or regrind material — in diameters from 12 inches (DN/ID 300mm) through 197 inches (DN/ID 5000mm), with diameter increments available every 100mm. Their winding process produces pipes with various wall structures: PR profiled wall (smooth interior, corrugated exterior), SQ structured wall (smooth inside and out with PP support tubes), OP large-diameter profiled wall, SP custom wall, and VW pressure-rated configurations. Ring stiffness classes range from SN2 through SN16 per ISO 9969, with custom ratings up to 32 kN/m². Wall thickness reaches up to 300mm, with internal pressure ratings to 3 bar. Standard laying length is 6 meters, with custom lengths from 1–6 meters, and pipes can be delivered pre-joined via butt fusion for faster installation. Applications include municipal water systems, irrigation, hydropower, fish passage, highway culverts, and slip lining rehabilitation of existing pipelines. Products comply with ASTM F894, DIN 16961, and EN 13476 standards. The company offers a KRAH Pipe Calculator mobile app for field engineering calculations.