Abstract: Iron pipe and other hollow articles are lined with a cementitious mortar containing a quantity of polymer particles and the pipe is rotated about its axis so as to stratify the mortar and develop a polymer rich inner surface that is subsequently cured, dried and heated to the polymer fusion temperature and then coated with a continuous layer of pure polymer.

Abstract: Iron pipe and other hollow articles are lined with a cementitious mortar containing a quantity of polymer particles and the pipe is rotated about its axis so as to stratify the mortar and develop a polymer rich inner surface that is subsequently cured, dried and heated to the polymer fusion temperature and then coated with a continuous layer of pure polymer.

Abstract: Control is provided over the casting of iron pipe in a centrifugal casting machine. The initial flow of molten iron from the pouring ladle into the trough actuates an electric eye. A second electric eye is actuated when the molten iron has flowed to the end of the trough. The centrifugal casting machine is rolled up to surround the trough, the bell end of the pipe to be formed being at the end of the trough. A computer is utilized to determine the velocity of the iron on a real time basis. This iron flow information is analyzed to calculate the bell flag time by a previously determined algorithm which takes into account the casting machine and the pipe size being cast. The bell flag time is the time in which the molten iron is allowed to flow into the bell section of the pipe being cast, before the casting machine is moved away from the trough end to form the rest of the pipe.