The Way to Describe the Steel Pipe Size

Find Out Steel Pipe Size in Chart

Winsteel Group manufactures a complete LSAW pipe size ranging from 16 inches to 56-inch O.D. We carry STD, Schedule 40, Schedule 80, and most intermediate wall thickness and heavy wall thickness LSAW steel pipe.

As a professional LSAW steel pipe manufacturer, Winsteel Group can produce hard-to-find sizes and grades as well as all common carbon steel pipe size and grade. If you want to buy steel pipe, how would you describe the steel pipe dimension you want?

steel pipe size chart
steel pipe size chart

The Way to Describe the Steel Pipe Size

If we want to give exact information about steel pipe, it should include steel pipe outside or inside diameter and wall thickness.

We usually express it like this. 36 inches, schedule 40 steel pipe. DN 400, Schedule 80 steel pipe. Or 1219.2 mm X 20.0 mm steel pipe.

All these descriptions are saying steel pipe dimension – outside diameter and wall thickness. So we can see that DN & NPS are all indicated the steel pipe size. Then what are DN and NPS?

What is DN?

DN means Nominal Diameter (inches). It is one way to describe steel pipe’s outside diameter. Reference tables are used to arrive at the outside diameter and pipe thickness based on the nominal steel pipe size and schedule. Pipes are available in different DN sizes. DN does not necessarily indicate the exact internal diameter. The DN is used to arrive at the pipe dimensions using standard tables and schedules.

What is NPS?

NPS is short for Nominal Pipe Size. It is another way to describe steel pipe O.D. It is a North American set of standard sizes for pipes used for high or low pressure and temperatures. The European and international designation equivalent to NPS is DN (diameter nominal), in which pipe sizes are measured in millimeters. And the term NB (Nominal Bore) is also frequently used interchangeably with NPS.

What is the Relationship Among DN, NPS and Millimeter?

In this chart below, we can see that DN 400=NPS 16 inches=406.4 mm. Pipe was originally measured in inches. For 100DN steel pipes works out to be exactly 4.5 inches X 25.4( mm/inch )=114.3 mm. That is why the outside diameter can’t be simple number like 100mm. 100DN = NPS 4 inches. =114.3 mm.

Steel Pipe Size – Wall Thickness Description

We can see that all DN and NPS describe outside diameter. As for wall thickness, we should find it in the steel pipe size chart. It has schedule 5s, schedule 40s, schedule STD, schedule XS, schedule 80, and schedule XXS and etc. So what is the figure if NPS 24 inches LSAW steel pipe wall thickness is schedule 40. Please check it in the pipe size chart. You will find out it is 17.48 mm.

It is very important to give a right size to buy the pipe you want.

Steel Pipe Dimension 3 Characters

A complete description for steel pipe dimension includes outer diameter (OD), wall thickness (WT), pipe length (Normally 20 ft 6 meter, or 40 ft 12 meters). Through these characters, we could calculate the pipe weight, how much pressure pipe could bear, and the cost per foot or per meter.

Therefore, that’s why we always need to know aright pipe size.