At 02:02 PM 4/15/02 -0700, you wrote: >So Harry, I can understand why a so-called 1 1/2" tubing would be 1 5/8" OD if >the tubing has a wall thickness of .0625. But are the other wall thicknesses >still 1 5/8" OD, letting the ID vary ? Seems an odd way of doing it.
Royce, Yes, it does but the purpose, as I understand it, was just as you say, to have a tube of a given nominal size to always be at least that size clear I.D. This seems to apply pretty much across the board until you get into large sizes and upper "schedules", what's known as heavy, extra heavy, and double extra heavy pipe. The I.D.'s in those tend to be below nominal. >1 1/2" tubing should have an ID of 1 1/2", regardless of wall thickness. It is the outside that should vary. What have I missed here ? Threads and Fittings. If the O.D. of each different tube size and wall gauge was allowed to vary with the wall thickness there would need to be an exponentially large number of fitting sizes. Regards, Harry
