Method of making a coupling for rigid pressure pipe

摘要: A coupling comprises a body of fiber glass reinforced plastic which has rubber sleeve embedded therein. The is one piece unit includes specially shaped sealing gaskets on either end and liner spanning the area between these gaskets. This stretched onto steel molding mandrel. stretching places under tension reduces cross-sectional compensates for thermal expansion during curing. mandrel/sleeve combination rotated in order to wind thermosetting resin impregnated roving around outer circumference combination, thus embedding matrix. cured at elevated temperatures, hardening into rigid with integral therewith. Thereafter hardened stripped from mandrel subjected further curing finishing operation.