Stainless Steel Pipe Sizes

Gauge Size | Pipe Schdule | Nominal Pipe Size | Sheet Metal Gauge | Stainless Steel Pipe Size | Stainless Steel Tube Size | Stainless Steel Pipe Specification | Stainless Steel Pipe Dimensions | ANSI Pipe Chart | Inch to mm Chart | EN 10253 4 Structural Dimensions of fittings ISO 5251 ISO 3419 | Stainless Steel Tubing Sizes

Stainless Steel Pipe Sizes include Gauge Size decide the wall thickness,Pipe Schdule according to ASME B36.10M, give us the OD size and wall thickness. Nominal Pipe Size similar with Pipe Schdule. ANSI Pipe Chart.

How old were you when you learned that a “2 by 4” isn’t a piece of lumber that measures 2 inches by 4 inches? Have you ever been told that 11/8-inch pipe doesn’t exist? Using the correct terminology when ordering material (or fittings, tools, or other items that must be used with these materials) can save a lot of time, headaches, and money!

Many products have a name that for convenience only approximates the material’s size. These are sometimes referred to as nominal dimensions. TubingChina describes nominal as “in name only.” In other words, you can’t trust the “name” dimensions in actual measurements or calculations. Differences and difficulties in correctly describing a tube and pipe are common in the metalworking industry.

Stainless Steel Pipe is a commonly used material in the ornamental iron industry. Pipe and tubing are not the same materials! Pipe was originally used for the movement of water, and therefore the ID (inside diameter) was the critical dimension. The nominal dimension for pipe is the ID. So, 1?inch pipe is NOT 1?inch outside diameter, but instead is nominally, (approximately) 1?inch inside diameter. Pipe is typically manufactured to looser tolerances and less expensive to purchase.

The wall thickness of Stainless Steel Pipe Sizes is designated by various “Schedules,” most commonly Sched. 5, 10, and 40. The exact wall thickness of any one schedule changes with the pipe size. A 1-inch Sched. 40 pipe has a. 133 inch wall, but a 2-inch Sched. 40 pipe has a wall thickness of 154 inches. For full details of Pipe Schdule

Stainles Steel Pipe, on the other hand, is typically produced to tighter tolerances and designed for consistent mechanical and structural properties. To further complicate matters, tubing can be manufactured to pipe size dimensions, and some companies market pipe to the fence industry as “fence tubing!” The thickness of a tube’s wall is normally described as a gauge. A specific gauge is consistent regardless of tube OD (outside diameter).

Stainless Steel Pipe Size Name Dim. Thickness
1” x schedule 5 pipe                         1.90″                          .065″
1” x schedule 40 pipe                        1.90″                        .145″
2”x schedule 10 pipe                        2.375″                        .065″
2”x schedule 40 pipe                        2.375″                        .154″
1/8″ OD x 18 gauge tube                   1.88″                        .049″
2”OD x 16 gauge tube                        2.00″                      .065″

Let’s look at a typical example…

Simon needs to buy a pipe-notching tool. When Simon calls and asks for a “2-inch pipe notched,” there are actually many different sizes that could possibly fit this description, as shown above.

This is only a partial list! You can see that all of the materials listed are about 2 inches, but depending on the tolerance and precision of the tool or mating part, describing all of them as 2-inch pipe is bound to cause problems.

So, given all the possible tube and Stainless Steel Pipe Size and all the various names used to describe them, how is the average person supposed to keep it all straight,  Whether you think your material is tube or pipe, when describing it, remember these key points:

Is a dimension OD (outside diameter) or ID (inside diameter)?
Is the dimension precise, (taken with a micrometer or calipers)?
Is the dimension approximate, (taken with a tape measure, eyeballed, etc.)?
What is the wall thickness/schedule/gauge?
 
If Simon had instead described his material as “a pipe just under (indicating that the dimension is approximate) 2-inch OD (outside diameter) by about 1/16-inch wall,” then he would have narrowed down the possibilities. Most likely, he is using 1 ?inch by Sched. 5 pipe.
 
You probably work with the same few sizes over and over. Look and see what your material supplier calls your material. You may wish to obtain and make a permanent file of “material spec sheets” for each size of pipe or tube you commonly use. This document should show precise dimensions, tolerance range, manufacturing method, coatings, or treatments, etc. These documents can be valuable and even serve as a sales tool. Your customers who scrutinize every detail may want to see why the same chain link fence job can cost so much more, based on the quality of the material ordered.

You probably have reference charts in your office for fractions to decimals, inches to millimeters, etc. If stainless steel tube and pipe are a routine material for your business, post a chart showing pipe sizes by OD, various schedules, and gauges for tubing. Make sure the employees who do purchasing understand these distinctions and are comfortable in correctly describing the various materials.

NPS Nomimal Pipes Size according to ASME B36.10M and ASME B 36.19 in mm

Nominal Pipe Size 1/8 to Nominal Pipe Size 3½

Nominal Pipe Size 4 to Nominal Pipe Size 9

Nominal Pipe Size10 to Nominal Pipe Size 24

Explanation:

Schedule 40 and 80 approaching the STD and XS and are in many cases the same.

From NPS 12 and above the wall thickness between schedule 40 and STD are different, from NPS 10 and above the wall thickness between schedule 80 and XS are different.

Schedule 10, 40 and 80 are in many cases the same as schedule 10S, 40S and 80S.

But watch out, from NPS 12 – NPS 22 the wall thicknesses in some cases are different. Pipes with suffix “S” have in that range thinner wall ticknesses.

ASME B36.19 does not cover all pipe sizes. Therefore, the dimensional requirements of ASME B36.10 apply to stainless steel pipe of the sizes and schedules not covered by ASME B36.19.

Application
Based on the NPS and schedule of a pipe, the pipe outside diameter (OD) and wall thickness can be obtained from reference tables such as those below, which are based on ASME standards B36.10M and B36.19M. For example, NPS 14 Sch 40 has an OD of 14 inches and a wall thickness of 0.437 inches. However the NPS and OD values are not always equal, which can create confusion.

For NPS ⅛ to 12 inches, the NPS and OD values are different. For example, the OD of an NPS 12 pipe is actually 12.75 inches. To find the actual OD for each NPS value, refer to the tables below. (Note that for tubing, the size is always the actual OD.)

For NPS 14 inches and up, the NPS and OD values are equal. In other words, an NPS 14 pipe is actually 14 inches OD.

The reason for the discrepancy for NPS ⅛ to 12 inches is that these NPS values were originally set to give the same inside diameter (ID) based on wall thicknesses standard at the time. However, as the set of available wall thicknesses evolved, the ID changed and NPS became only indirectly related to ID and OD.
For a given NPS, the OD stays fixed and the wall thickness increases with schedule. For a given schedule, the OD increases with NPS while the wall thickness stays constant or increases. Using equations and rules in ASME B31.3 Process Piping, it can be shown that pressure rating decreases with increasing NPS and constant schedule.[4]

Some specifications use pipe schedules called standard wall (STD), extra strong (XS), and double extra strong (XXS), although these actually belong to an older system called iron pipe size (IPS). The IPS number is the same as the NPS number. STD is identical to SCH 40S, and 40S is identical to 40 for NPS 1/8 to NPS 10, inclusive. XS is identical to SCH 80S, and 80S is identical to 80 for NPS 1/8 to NPS 8, inclusive. Different definitions exist for XXS, but it is generally thicker than schedule 160.

The “S” designation, for example “NPS Sch 10S”, most often indicates stainless steel pipes.

The terms Nominal Bore (NB) and Nominal Diameter (DN) are also frequently used interchangeably with Nominal Pipe Size (NPS). Nominal Bore (NB) is European Designation equivalent to NPS. For NPS 5 and larger, the Nominal Diameter (DN) is equal to the NPS multiplied by 25.

Initially there are only three pipe wall thicknesses in use –

• Standard (STD)
• Extra Strong (XS)
• Double Extra Strong (XXS)

However with the advancement of industrial age and use of pipes in varying pressure and temperature conditions, these three sizes did not fit all applications. There have been many revisions and additions to the tables of pipe sizes based on industry use and on standards from API, ASTM, and others. Today we have a range of wall thicknesses, namely:

• SCH 5, 5S, 10, 10S, 20, 30, 40, 40S, 60, 80, 80S, 100, 120, 140, 160, STD, XS AND XXS.

Stainless steel pipes, due to less risk of failure due to non-corrosive property, permitted the use of pipes with thinner wall thickness. Initially thinner pipe schedules 5S and 10S had been created and afterwards other “S” sizes followed later. Stainless steel pipes are most often available in standard weight sizes (noted by the S designation; for example, Sch 10S). However stainless steel pipe can also be available in other schedules. Due to their thin walls, the smaller “S” sizes can not be threaded together according to ASME code, but must be fusion welded.

In new schedule system,

• Schedule Standard (STD) is identical to SCH 40S, and 40S is identical to 40 for NPS 1/8 to NPS 10, inclusive.
• Schedule Extra Strong (XS) is identical to SCH 80S, and 80S is identical to 80 for NPS 1/8 to NPS 8, inclusive.
• Schedule Double Extra Strong (XXS) wall is thicker than schedule 160 from NPS 1/8 in to NPS 6 in inclusive, and schedule 160 is thicker than XXS wall for NPS 8 in and larger.

Nominal Pipe Size and Schedule collectively sets the pipe outside diameter (OD) and the wall thickness (and hence the internal diameter (ID) is automatically fixed). For example, NPS 14 Sch 40 has an OD of 14 inches (360 mm) and a wall thickness of 0.437 inches (11.1 mm).

Related References:
Pipe Schedule
Stainless Steel Tube Size