Method of heating plastic pipe

摘要

An inplace gasket belling machine wherein a plastic pipe is received in a tilt clamp fixture and tilted thereon for receiving a heating bell on one end portion of the pipe. Heated fluid is directed over the inserted pipe end portion. The heating bell may be withdrawn from the pipe in intermittent steps to afford a temperature gradient along the pipe end portion. The pipe is then tilted to a horizontal disposition for the insertion of a gasket belling mandrel into the heated end portion of the pipe. A gasket magazine is supported adjacent the mandrel for automatically placing an annular gasket on the mandrel for insertion into the pipe end portion. The mandrel includes an outer housing and a mandrel body portion telescopically received within the outer housing. The outer housing has a stop shoulder and a gasket positioning sleeve extended forwardly therefrom. The mandrel body portion has a flared pipe expanding portion and a gasket carrying portion rearwardly thereof. Upon insertion of the flared portion into the heated end of the pipe, the outer housing collapses onto the mandrel body portion for precise positioning of the gasket within the pipe end portion. Upon withdrawal of the gasket positioning sleeve from said pipe end portion, the pipe end portion is collapsed by vacuum means onto the mandrel body portion and cooled prior to withdrawal of the mandrel body portion from the belled pipe end portion.