Australia
Pipe Details
- A schedule 80 nozzle on a thermal oxidizer knockout pot experienced corrosion covering 60 mm (2.36 in) from the connection to the lower head
- 90°C to 100°C (194°F to 212°F) operating temperature
- 0.15 to 0.20 bar (2.17 to 2.9 psi) operating pressure
Summary
- Contour repaired a nozzle on a thermal oxidizer knockout pot with 60 mm (2.36 in) of significant corrosion
- 2 technicians carried out the complete repair in 2 days
- No hot work required
- Minimal shutdown during repair
Inspections at an onshore processing plant that receives gas from an offshore facility revealed a severely corroded nozzle on a thermal oxidizer knockout pot.
The corrosion covered 60 mm (2.36 in) from the connection to the lower head on a 50 NB schedule 80 nozzle, thinning the nozzle wall to approximately 1 mm (0.04 in) at its weakest point. The extent of the corrosion varied over this length, but the pipe was in sound enough condition to be repaired.
Designed for 90°C to 100°C (194°F to 212°F) operating temperature and 0.15 to 0.20 bar (2.17 to 2.9 psi) operating pressure, the knockout pot was critical to operations. Plant owners wanted a quick repair, and having used composite solutions to address corrosion problems in the past, appealed to CSNRI to provide a solution.
The repair provided was CSNRI's Contour, an engineered wet applied repair system featuring quad-axial stitched fiberglass cloth applied in a wet-lay system with two-part epoxy and a filler material.
PipeServ Engineering provided CSNRI trained and certified installers to repair the damaged nozzle. A team of 2 technicians wrapped the damaged area with the Contour wet applied repair system. Filler material was applied over the corroded area on the first day, followed by quad-axial stitched fiberglass cloth affixed with a two-part epoxy the next day.
The vessel was shut down for a short time during the repair process, but the composite solution precluded an extended shutdown. The Contour repair took place without introducing hot work and its associated hazards, restoring the nozzle to a safe operating condition in only two days.
