Pipes & Tubes
Stainless steel is an alloy made of steel with a chromium base. Mixing steel with other components such as chromium, molybdenum, copper, silicon, carbon, and aluminum makes an alloy called stainless steel. Stainless steels are designed materials providing strong resistance to corrosion, power, and properties of production.
Pipes and tubes manufactured from different grades of stainless steel are common on the market and are sold according to use and form of user. In piping, various types of stainless steel are used. Because of its outstanding corrosion resistance properties, Stainless Steel is the most commonly used commodity in Process industries.
Pipe was originally produced to carry liquids inside the pipe and was therefore sized according to the interior capacity. This standard allowed engineers to calculate the amount of volume the pipe could transfer when designing projects.
As such, listed pipe sizes are identified by "Nominal Pipe Size (NPS)" and are generally closer to the inside diameter (ID) of the pipe and have little or no resemblance to the outside diameter (OD).
The wall thickness (W) of the pipe is listed as a "schedule". The larger the number of the " Schedule" the thicker the pipe wall is. However as the pipe size increases, so does the thickness of each schedule. As such, a Schedule 40 pipe in 1 inch NPS, has a thinner all than a Schedule 40 pipe in 3 inch NPS.
| 1/4 inch | 0.540 inch |
| 1/4 inch | 0.540 inch |
| 3/8 inch | 0.675 inch |
| 1/2 inch | 0.840 inch |
| 3/4 inch | 1.050 inch |
| 1 inch | 1.315 inch |
| 1-1/4 inch | 1.660 inch |
| 1-1/2 inch | 1.900 inch |
| 2 inch | 2.375 inch |
| 2-1/2 inch | 2.875 inch |
| 3 inch | 3.500 inch |
| 3-1/2 inch | 4.000 inch |
| 4 inch | 4.500 inch |
| 5 inch | 5.563 inch |
| 6 inch | 6.625 inch |
| 8 inch | 8.625 inch |
Tubing sizes are listed as "Outside Diameter (OD) and Wall Thickness (W). Listed sizes of tubes are exact, a 1 inch "tube" will measure 1 inch on the OD. The "Inside Diameter" (ID) will become smaller as the wall thickness increases.
To find the "Inside Diameter" (ID) of any tube, simply subtract the wall thickness(x2) from the "Outside Diameter" (OD) of the tube.