Thank you both for your replies.
RAS = Return Activated Sludge, it's the "bottom" of the final clarifiers that is being returned to the aeration tanks to help maintain the microbial populations. I am not exactly sure of the pressure, but I don't think it would exceed 200 kPa. It would be...
I'm looking to repair some large diameter (42", 30" and 20") steel RAS pipes. It needs to be a medium term solution, as we can't keep up with "patchwork" and they are scheduled to be replaced in just under 10 years. Weaknesses are at the welds and throughout the pipe wall.
Ideally, I'd like...
