How is tubing measured

Click image to enlarge. Tubing is measured using the size of the inside diameter I. Wall thickness, along with the plastic material, also determines the rigidity and weight of plastic tubing. Even if two tubes have the same outer diameter, they can have very different inside diameters depending on the wall thickness. The I. Early pipe manufacturers made the walls in the smaller sizes much too thick, and in correcting this error in design, they took the excess from the inside to avoid changing the sizes of the companion fittings.

For sizes larger than inch, NPS corresponds to the actual outside diameter. For each nominal pipe size, the outside diameter O. The wall thickness of tubing is measured in inches.

You can see by the chart at the right, not all 12 Gauge allows a thickness between 0. The typical value, which is not half way between, is used for calculation of section properties.

Once again, pipe wall thickness is a bit more complicated. Pipe Sizes. Also, Low Density and Rural poly pipe are measured by their inside diameter, while Metric poly is measured by the outside diameter. Similarly, how is copper tubing measured? In the plumbing trade the size of copper tubing is measured by its outside diameter in millimetres. Tubing in 8 mm and 10 mm outside diameters is called "micro bore" and is easier to install, although there is a slightly increased risk of blockage from scale or debris.

Although it is related to the outside diameter, it is significantly different. In short: Tube is measured by outside diameter , pipe is measured by inside diameter. There is often confusion as to which size die the customer actually needs - Pipe Size or Tubing Size. Keep in mind that pipe size refers to a nominal - not actual - inside pipe diameter. Schedule refers to the pipe's wall thickness. By the inner diameter ID. Blue Stripe Poly Pipes are fundamentally the same as black poly pipes , however it is externally blue striped to code what type of medium mains water it contains, also known as potable water mains.

HDPE pipe shall have a minimum density of 0. Our rural " Green Stripe " and " Green Stripe PN8" polyethylene pipe is manufactured using PE which is also known as " HDPE " and so it is suitable for general water transfer, irrigation, stock watering systems and general water systems where the system pressure will never exceed kPa psi or 80m of head.

MDPE pipe is measured by its outside diameter. MDPE stands for "Medium density polyethylene", if you were wondering. We do not stock the old black plastic Alkathene mains pipe or fittings any more, but we do have a page with information about its sizes.

Remember that water pressure decreases by a half-pound per square inch for every foot pipes extend above your water supply. The pipe schedule refers to the pipe wall thickness. The higher the schedule , the thicker is the pipe wall. For example: 2-inch nominal size steel pipe: schedule 40 has a wall thickness of 0.

The result is the combined thickness of the pipe walls on both sides of the pipe.