ggrindle
Mechanical
- Jul 21, 2006
- 32
All,
Need some advice. I just visited a shop where we are having some 2205 ductwork fabricated for FGD outlet duct use. I know that termpature and HAZ is important and bead sequence should be watched.
When I got to the shop they used a machine to weld about 70% of the welds. I inquired about the process and it involves butt welding piece of plate together. I asked about the bevel and gap and was told that this machine essential butts up 2 pieces of plate (1/4 inch thick) with square edges (no bevel and no gap) and then welds them together.
The welds are beautiful..prettiest I've ever seen, but the question I have is regarding temperature.
Furthermore 2209 wire is used for the weld material, but I can't imagine very much is used since the plates are square and butted up to one another in this process.
From the standpoint of corrosion, is this process inferior to mig with bevel and gap and proper bead sequence and attention to heat input?
One other thing that got my thinking on this is they used 4' wide plates for the construction because it was cheaper. But of course that means more welds. I didn't specify a size of plate because I assumed the labor savings using larger plates would make it beneficial for any shop to specify 8 or 12' wide plates. But with this machine weld process the welds don't add much labor and so the savings going with less wide plates was greater than the labor to run the weld machine. This is a new one on me.
Advice anyone. Need I be worried?
Need some advice. I just visited a shop where we are having some 2205 ductwork fabricated for FGD outlet duct use. I know that termpature and HAZ is important and bead sequence should be watched.
When I got to the shop they used a machine to weld about 70% of the welds. I inquired about the process and it involves butt welding piece of plate together. I asked about the bevel and gap and was told that this machine essential butts up 2 pieces of plate (1/4 inch thick) with square edges (no bevel and no gap) and then welds them together.
The welds are beautiful..prettiest I've ever seen, but the question I have is regarding temperature.
Furthermore 2209 wire is used for the weld material, but I can't imagine very much is used since the plates are square and butted up to one another in this process.
From the standpoint of corrosion, is this process inferior to mig with bevel and gap and proper bead sequence and attention to heat input?
One other thing that got my thinking on this is they used 4' wide plates for the construction because it was cheaper. But of course that means more welds. I didn't specify a size of plate because I assumed the labor savings using larger plates would make it beneficial for any shop to specify 8 or 12' wide plates. But with this machine weld process the welds don't add much labor and so the savings going with less wide plates was greater than the labor to run the weld machine. This is a new one on me.
Advice anyone. Need I be worried?