Coating metallic pipes internally and externally with plastics - by preheating pipes, cleaning pipes by blasting , covering with epoxy! resin so flexible joints form between pipes and cooling

摘要

Metallic pipes are coated with plastics materials internally and externally in a continuous process in which all the steps take place automatically with considerable saving of energy. The pipes are first preheated and then subjected to internal and external cleaning using a blasting process. Pipes are then fed in closely spaced formation through an induction oven for heating the pipes to a temp. at which the outer face of the pipes is covered with an epoxy resin layer. Layer is continuous along the pipes such that flexible joints are made between pipe sections. Pipes are then cooled at 40-50 degrees C for inner coating, the joints cut and the pipe ends cleaned of coating along sections 10 cm long by brushing. Following brushing the pipes are coated internally with layers of required thickness. After coating the pipes are passed through a control section for checking the quality, and if required, for correction of prodn. faults before dispatch to store.