Doubling the Crew to Complete Major Overhaul in Half the Time

Type of Plant:Fossil

Client Challenge

Of the two generators at a major utility, the tubing in the newer generator was wearing out twice as fast due to the frequent pressure washing required by new federal regulations on nitrogen oxide emissions. Every five years, the generators are taken down for two months for major overhaul. However, with both generators to be overhauled, the outage period was reduced to just one month. The scope of work to be completed was enormous, particularly considering the aggressive outage schedule and limited access to the boiler. The primary superheater was to be replaced, including removing and replacing 438 PSH elements and 58 Chordal water wall panels of assorted sizes.

Aquilex Solution

The first step was to assemble the team, which was doubled to come in on schedule. A significant coordination challenge was inherent in the size and structure of the workforce: multiple jobs with 120+ men per shift, not inclusive of an additional ten plus subcontractor crews. In order to access the boiler, the team cut a hole in the side of the boiler so that cranes could hoist out old pipe and bring in 1.3 millions pounds of new pipe.

Results

The project took nearly four weeks of around the clock work by 70 welders. In total, 92 miles of pipe were joined with more than 3,487 code welds. Although there were a number of unforeseen obstacles, there was no schedule slippage and the x-ray was completed with only a 4% rejection rate.