# The PDF Pipe O.D. chart was created by the leaders in PipeJoint.

The thickness of the pipes used in Process Plants can be defined using the Pipe Schedule Number.

The mass production era gave rise to the standards of wrought steel Pipe schedule and pipe sizes.The three sizes of pipes available at that time were standard weight, extra strong, and double strong.

Three sizes are not enough to meet the requirement with the use of pipes in different pressure and temperature conditions.The wall thickness and diameter of the pipe will be combined into a schedule number.

The size of the pipe is determined by theNominal pipe size.The 6” is the nominal size of the pipe.NPS 14 and above Outside Diameter is the same as NPS for the pipe sizes.You have to learn how pipes are made to understand this concept.

Fixed outside diameter is the basis for the manufacturing of NPS 18 to NPS 12.The inside diameter of the pipe decreases if the wall thickness increases.There is an OD and ID of the pipe.

The Nominal Size of a pipe is related to the manufacturing of NPS 14 and above pipe OD.You have more clarity of the concept with this example.

From the table, you can see that the Pipe ID is close to the NPS and the OD is the same.

TheNominalBore is often referred to as NPS.There is no difference between the two.It is an American way to refer to pipe dimensions.When the dimensions of the pipe are shown, people refer to the sizes in New Zealand.When someone says 25 or 50 pipes, they are talking about the same thing.

The European equivalent of NPS is called Diameter Nominal and it is an International designation.You have to note that the sizes of the pipes are different from one another.

The 2” pipe is referred to as DN 50.You can get any NPS with 25.The table below is easy to understand.You don’t see a change in other dimensions when you use DN.

From this table, you can see that the initial pipe size increases by 14 and then by 1.Form 6” to 42” increases by 2 steps.

The pipe schedule talks about pipe wall thickness.The schedule number is based on Barlow’s wall thickness formula and is designed to simplify the ordering of the pipe.

The schedule number indicates the approximate value of the expression 1000 x P/S where P is the service pressure and S the allowable stress, both expressed in pounds per square inch.

Schedule 40 is a pipe thickness designator.For a given material, schedule 40 pipe can tolerate a certain amount of pressure.

Schedule 40 pipe is thinner than schedule 80 pipe.The allowable stress for material at a given temperature is fixed in the above formula.Increasing the service pressure schedule number will increase the pipe wall thickness designator.

The cost of carbon steel pipe is lower than that ofstainless steel.The advancement of high alloy stainless steel and fusion welding less thickness pipe can be done without fear of failure.

Different schedule numbers have been introduced to reduce the cost of material.The Schedule no with “S” is introduced for the pipe.10S is an example.

The available schedule numbers for carbon steel and STAINLESS steel pipe are summarized in the table below.

You can use the formula given below to calculate the ID of the pipe.

There are common dimensions listed in A530.Each product has its own requirements and when given in that specification will govern over the A530.