Original Date: 07/21/2003
Revision Date: 01/18/2007
Information : Quonset Point Nuclear Pipe Shop
Electric Boat Corporation, Quonset Point Facility continues to meet the needs of the “Nuclear Navy” by enhancing the operations of its Nuclear Pipe Shop. Shop facilities and fabrication operations for piping systems have been improved by new and innovative methods of process control with in-shop training/communication, enhanced cleaning methods, and weld process control through automation.
As the “Nuclear Navy” was being established, it was quickly recognized that stringent requirements would be placed on materials and welded components for nuclear submarines. Key to the operation of nuclear submarines is the piping systems installed throughout the ship. Electric Boat Corporation, Quonset Point Facility (EBQP) understood the need for improved pipe fabrication and established a Nuclear Pipe Shop in 1978. The shop was set up to be autonomous, providing maximum efficiency in the fabrication and testing of nuclear piping assemblies and components. As such, the shop was often referred to by management and the Navy as the model for other manufacturing facilities to follow. Over time, other EBQP shops adapted the Nuclear Pipe Shop model to perform their fabrication activities.
In May 2002, the Nuclear Pipe Shop was relocated to a newly refurbished shop on site. EBQP, as part of its commitment to continuous improvement, ensured that the new facility implemented the latest process improvements. The new shop promotes better material flow, material control, and cleanliness by restricting access to the enclosed shop area. For pipe fabrication, the material is received into the shop, processed, cleaned, fabricated, inspected, packaged and shipped directly from the shop. Only limited work (e.g., radiography, test, and bend operations) is performed outside of the shop. Enhancements within the new shop include: Computer Kiosk Station: Provided for all personnel in the shop and used to access current work instructions/procedures, training videos, and work status.
Environment Control: Used to control the volume of air recycled to a minimum of ten times per hour. The compressed air is filtered to eliminate contamination that can be detrimental to nuclear piping systems and components. The argon system for welding is continuously monitored for acceptable dew point levels of moisture and oxygen.
Pipe Cleaning: The traditional method was performed by soaking a lint-free cloth with solvent and pulling it through the pipe with an attached nylon lanyard, a difficult process requiring an average of 15 minutes per pipe assembly to perform. EBQP’s innovative approach to cleaning the internal diameter of piping is now performed by forcing a foam plug soaked with an approved solvent through the pipe with filtered, compressed air. This approach produced superior results in less than 20% of the time (three minutes).
Pipe Welding: Performed by gas tungsten arc welding (GTAW), achieved by manual or automated modes, in accordance to NAVSHIPS 250-1500-1 and MIL-STD-278. Sixty percent of the welding is performed by automation using either horizontal rolled or orbital welding equipment. New state-of-the-art orbital arc welding equipment is being implemented for pipe welding using a system from Arc Machines, Inc., which includes data acquisition of the arc welding process to improve process control and quality.
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