Gem Bids For 300 Mm Internal Dia Double Wall Corrugated With Externalannular Corrugation & Smooth Internal Walls, 110 Mm Diahigh Density Polyethylene Pipe Conforming To Is: 4984-1985pe-63 & 6 Kg/sq. Cm., 50 Mm Dia High Densitypolyethylene Pipe Conforming To Is- 4984-1985 Pe-63 & 6kg/sq. Cm.