Waterbox Divider Plate Gasket
Case History #007 REV.04-97
LOCATION: Refuge fueled cogeneration plant, Maryland
The gasket that seals the waterbox divider plate to the tubesheet blew out, causing cooling water to erode the carbon steel divider plate.
The top and bottom of the divider plate was abrasive blasted to SP-5 standards with a 3-mil minimum profile. After thoroughly cleaning the area, a strip of 1/4-inch gasket material cut to match the thickness of the original divider plate was fit and glued to the tubesheet.
A base coat of ARCOR™ S-30 was then installed top and bottom and allowed to set up. Next, a strip of plexiglass was fit and propped up on the bottom of this repair to act as a temporary form. ARCOR™ TS-RB was then installed by squeegee into the eroded area and built up flush to the surrounding substrate. This was allowed to set up overnight.
The following morning, the plexiglass was easily removed to show a filled repair, right up to the new gasket. The next step was to install a fiberglass reinforcement to the repair. This was accomplished by applying successive layers of 9.5-oz. glass strips and composite resin material. A total of 10 layers were installed on each side of the divider plate.
This repair was completed by installing a top coat of ARCOR™ S-30 Blue and a bead of ARCOR™ Arcthane at the tubesheet / waterbox joint.
This project was completed in April 1991. Yearly inspections have shown that this repair looks and is performing as good as the day it was installed.
Corroded tubesheet joint.
Primed and reinforced with fiberglass mat.
Joint top-coated with ARCOR S-30 Blue.