Pipes are round hollow sections for the transfer of fluids, gases, powders, and more.
Pipe sizes are designated by a nominal pipe size (NPS or DN) that represents a rough indication of pipe capacity. It is measured by their outer diameter together with the wall thickness (also called schedule). OD minus 2 times schedule determines the inner diameter of the pipe, which determines its capacity. Pipes have many different outer diameters and schedules to accommodate different applications depending on the pressure requirements.
Pipes come in a wide range of carbon and stainless steel material to cope with the many different products conveyed.
The most common connections pipes come with are bevel, weld, and threaded ends.
Tubes are hollow sections that come in round, square, rectangular, and oval shapes. They are used for mechanical applications, general fabrication, pressure equipment, and also product transfer.
Tube have more accurate sizing. They are measured by the outer diameter and wall thickness. For example, a 2” Tube OD will be 50.8mm. Sizes are more restrictive than pipes, tubes 6” and above are difficult to source.
Tubes are available in carbon steel, low-alloy steel, stainless steel, nickel-alloy.
Tubes are usually only available in weld end.
Sanitary Tubing, sometimes also referred to as dairy tubing, are only available in round cross-sections. Dairy tubes are specifically used for product transfer in industries such as food and beverage, pharmaceutical, personal care. Unlike pipes, and tubes, dairy tubes are commonly available in different degrees of polish depending on the application.
Dairy tubes are also accurately measured by the outer diameter and wall thickness, although sizes might be even more limited.
Such hygienic tubes are only available in stainless steel, 304 and 316.
Sanitary tubes are also only available in weld end.
NKE is an importer and supplier of sanitary/dairy tubes, look at our sanitary tubing page.