for all those interested.......
What's the difference between a pipe and a tube?
More often than not, people guess it has something to do with the quality of the materials, but that's got nothing to do with it. The difference between a pipe and a tube is how they are measured, and ultimately what they are used for.
[FONT=Arial,Helvetica,sans-serif] A pipe is a vessel - a tube is structural.[/FONT]
[FONT=Arial,Helvetica,sans-serif] A pipe is measured ID - a tube is measured OD.[/FONT]
[FONT=Arial,Helvetica,sans-serif] How they are measured... Pipes are measured ID or inside diameter because they are vessels. Tubes are measured OD or outside diameter because they are structural. [/FONT]
[FONT=Arial,Helvetica,sans-serif] Pipes have a consistent ID regardless of wall thickness. In other words, a 1/2" high pressure pipe may need a 2" thick wall, but the ID will still only be 1/2" even tho the OD is 4.5". [/FONT]
[FONT=Arial,Helvetica,sans-serif] Generally speaking, a tube will have a consistent OD and it's ID will change. Engineers see tubes and pipes with different eyes. [/FONT]
[FONT=Arial,Helvetica,sans-serif] A tube is structural.[/FONT]
[FONT=Arial,Helvetica,sans-serif] By having a consistent OD they can vary wall thickness, changing the ID, to increase strength. Because they are consistent OD, they have predictable characteristics. [/FONT]
[FONT=Arial,Helvetica,sans-serif] Again, the difference is simple, it's how they are measured and what their intended uses are.[/FONT]