- Company: HART Engineering Corporation
- Industry: Power
- Location: Johnston, Rhode Island
- Expected Completion Date: April 5, 2013
- Project Website
This short term plant shutdown project was to remove and replace (2) 20” Hot Reheat Bypass Attemperators Valves and (2) 8”x12” Main Steam Bypass Attemperators at Entergy Gas Power Plant in Johnston Rhode Island. This involved extensive crane work, partial removal of the building envelope, the provision of supplemental structural steel and high temperature chrome welding. The work of this project was to improve plant operational efficiency, improve plant reliability and reduce the cost of electrical power to customers.
What impact does this project have on America?
This project was necessary for Entergy to maintain power supply services to their commercial and residential customers throughout the Northeast.
What interesting obstacles or unusual circumstances did you overcome to complete the project?
This project involved the use of a 120 ton crane for removal of the attemperator valves which were located in the inner parts of the building which required extensive crane reach and height. This project also involved the use of high heat chrome welding which requires the pipe and valves to preheated and maintained at temperature to allow for the proper welding procedure. Along with the high heat welding these valves must be post weld heat treated which is a 12-18 hour process as well as 100% non-destructive weld testing.
What dangers and risks did you encounter, and describe any extraordinary methods used to keep workers safe?
Risks and dangers included adverse winter weather, multiple-shift operations, outdoor work in extreme cold conditions, arc flashing and overhead crane work. Welding activity was coordinated with other trades work to reduce the exposure of workers to weld flash and limit the time of the shut-down. During the crane work all adjacent work areas were restricted to anyone but those working with the crane and daily pre-shift lift review meetings were conducted to insure the safety of all workers. The combination of close communication with the client’s facility teams and pre-/through-shift coordination reviews allowed this complex, fast-moving program to be completed without team member injuries, component/property damage or loss of service to the public.
How did you leverage new technologies to work faster and reduce waste?
One method that used during the attemperator removal process was the use of a pneumatic pipe cutter which allowed for faster cutting times, maintained perfect cuts and beveling. This approach reduced the amount of existing system piping that needed to be removed, requiring less new material to be cut and trimmed to size. This helped to minimize the prep work needed for each individual weld (which in some cases could take as many as 8-10 hours to complete properly).