mjpetrag
Mechanical
- Oct 16, 2007
- 224
We have a boiler that has several tubes that have undergone overheating tube ruptures due to poor water treatment and subsequent tube blockages. We have fixed the feed water quality issue and have just completed an acid wash of the boiler to remove any blockages from the tubes, steam drum, mud drum, and water wall headers. We found 3 other tubes that were visually overheated and confirmed with Brinnell Hardness testing that we will be replacing.
After the acid wash, we hydrostatic tested the boiler to 1.5x MAWP at 70 F water with no leaks.
The only problem I see is if we have tubes that are brittle that we have not picked up on visual inspection could potentially fail in operation. We are going to test every other tube on the water walls for hardness while we repair the 3 overheated tubes to help pick up any potential brittle tubes.
My question is, if the boiler hydrotest passed at 1.5x MAWP at 70 F, but we have brittle tubes that have not been tested or repaired, however we have cleared all restrictions in the tubes and can maintain good circulation to prevent further overheating, is it likely those brittle tubes will fail in operation? Is hydrostatic testing a surefire way to pick up a brittle fracture of a tube before putting the boiler back into service?
-Mike
After the acid wash, we hydrostatic tested the boiler to 1.5x MAWP at 70 F water with no leaks.
The only problem I see is if we have tubes that are brittle that we have not picked up on visual inspection could potentially fail in operation. We are going to test every other tube on the water walls for hardness while we repair the 3 overheated tubes to help pick up any potential brittle tubes.
My question is, if the boiler hydrotest passed at 1.5x MAWP at 70 F, but we have brittle tubes that have not been tested or repaired, however we have cleared all restrictions in the tubes and can maintain good circulation to prevent further overheating, is it likely those brittle tubes will fail in operation? Is hydrostatic testing a surefire way to pick up a brittle fracture of a tube before putting the boiler back into service?
-Mike