tub·ing 
(tbĭng, ty-)
(tbĭng, ty-)n.
1.
a. Tubes considered as a group.
b. A system of tubes.
c. A piece or length of tube.
2. Tubular fabric, such as that used for making pillowcases.
3. The activity of riding an inner tube or other inflated device for fun or relaxation, as in a stream, down a snow-covered hill, or towed behind a motorboat in a body of water.