Abstract: The present invention relates to in-line coating of a continuously moving substrate, such as a tube or conduit, preferably of the type used for applications such as fire sprinkler piping. The present invention includes a fire sprinkler pipe defining an internal pathway. The interior surface of the pipe is coated with a low friction material such as a fluoropolymer, silicone or epoxy composition.

Abstract: An improvement is accomplished in apparatus for the continuous production of tubing from tubing stock, and like, elongated, closed structures from appropriate stocks. The apparatus includes welding means for continuously welding the tubing stock to form the tubing, with the welding occurring at a welding station. Downstream of the welding station are stations for the further processing of the tubing after welding, which generate conditions adverse to interior coatings. In apparatus as described, the improvement comprises several inventive features. A spray head provides for spraying of coating, and fits within the tubing. An elongated, flexible lance locates the spraying means downstream of the processing stations which generate adverse interior coating conditions, by introduction of the spray head into the tubing interior upstream of the welding station, and after introduction, movement of the spray head into the desired downstream position.

Abstract: A method and apparatus for applying a coating to a continuous length of tubing. A coating chamber having entry and exit ports substantially encloses a portion of the tubing while permitting the tubing to pass continuously therethrough. Airflow into the coating chamber through the exit port strips excess coating material from the tubing surface. Air is withdrawn from the coating chamber by vacuum pumps through one or more separation chambers which separate entrained particles or droplets of coating material from the air. The coating chamber is preferably disposed at a distance from the separation chamber(s). The vacuum line connecting the coating chamber with the separation chamber(s) is preferably flexible or breakable. The separation chambers are preferably capable of being operated in series or in parallel. Adjustable masks are preferably provided at the entry and exit ports of the coating chamber. A seal is preferably provided at the entry port.

Abstract: A method and apparatus for applying a coating to a continuous length of tubing. A coating chamber having entry and exit ports substantially encloses a portion of the tubing while permitting the tubing to pass continuously therethrough. Airflow into the coating chamber through the exit port strips excess coating material from the tubing surface. Air is withdrawn from the coating chamber by vacuum pumps through one or more separation chambers which separate entrained particles or droplets of coating material from the air. The coating chamber is preferably disposed at a distance from the separation chamber(s). The vacuum line connecting the coating chamber with the separation chamber(s) is preferably flexible or breakable. The separation chambers are preferably capable of being operated in series or in parallel. Adjustable masks are preferably provided at the entry and exit ports of the coating chamber. A seal is preferably provided at the entry port.