•In pipelines of gasses flow functional reliance l = f(De,Re) is means ,that friction depend from the equivalent roughness and flow regime. | COMPRESSIBLE FLOW FRICTION Friction in gas pipelines Coefficient In pipelines of gasses flow functional reliance l = f(De,Re) is means ,that friction depend from the equivalent roughness and flow regime. For steel material of gas pipes equivalent roughness De = 0,1 mm . For copper or plastic gas pipes De = 0,0015–0,003 mm only.(see Table) According the Moody chart,5 zones of friction factor is valid: 1) Laminar laminar flow friction factor is independent of relative roughness,and can be estimated by formula: (1) Where : Re 4000 ,and Re 4000, and 10 4000, and Re e/d >500) surface roughness completely dominates the character of the flow near the wall.( = f ( e/d))From the (5) formula we can find in that case: (6) Equivalent Roughness efor New Pipes Pipe Equivalent Roughness, in mm Riveted steel – Concrete – Wood stave – Cast iron Galvanized iron Commercial steel or wrought iron Drawn tubing Plastic, glass (hydraulically smooth) NOTE: Even for hydraulically smooth pipes the friction factor is not is,there is a head loss in any pipe,no matter how smooth the surface is is a result | COMPRESSIBLE FLOW FRICTION Friction in gas pipelines Coefficient In pipelines of gasses flow functional reliance l = f(De,Re) is means ,that friction depend from the equivalent roughness and flow regime. For steel material of gas pipes equivalent roughness De = 0,1 mm . For copper or plastic gas pipes De = 0,0015–0,003 mm only.(see Table) According the Moody chart,5 zones of friction factor is valid: 1) Laminar laminar flow friction factor is independent of relative roughness,and can be estimated by formula: (1) Where : Re 4000 ,and Re < 105,and Re e/d<10) the Blazius formula is fit: (3) In the same III zone when pressure is medium or high and .