pipe size and types

PIPE AND PIPE SIZE

Pipes are the common medium to transport any fluid, anywhere even it is in gas, liquid or solid-state.

INTRODUCTION

The pipe is a hollow cylinder, that is used to transport the fluids from one place to another place .it may be in different size and shape. Pipes are used widely in today's era with its various kinds, size, and shape.

PIPE SIZE

To identified pipe size, there are three common methods are used worldwide like NPS, DN, and Schedule

NPS

Nominal Pipe Size: NPS represents the size of the pipe according to the American system and it shows the size of the pipe in the inches. If it's looked at scientifically, then the VALUE between OD and ID is called NPS. However, this definition only applies up to 12 inches. NPS, above 12 inches, NPS is equal to OD, which means if there is a 14"pipe, then NPS = OD means 14".Similarly, NPS 18 "means OD of the pipe is18".Now the question arises that how to get the size of pipe below 12 "?There are some codes prescribed by ASME for this, according to which we can get the size of pipe below 12 "like ASME B36.10 For wrought steel and ASME B36.19 For Stainless steels.

Example

If we look at the OD of NPS10"pipe, according to ASME Chart, 10" = 10.750",but above 12" it will be same like:NPS14"=14"OD

DN

The second way to measure the size of the pipe is DN, here it is a notable point that the standard value for DN is 25. it is according to British standard and its measurement is in millimeters.In this method, we take the size of the pipe is in "mm", as we know that 1" is 25.4 millimeters but here it takes NPS 1"= DN25 ie 1"= 25DN, NPS 2"= 50DN.

Example

Now we take an example of 2" pipe, now we know that 1"=25.4mm SO 2"=25.4 x2 =50.8mm but as per ASME B 36.10, the OD of 2" pipe is 2.375" SO 2.375" x25.4 = 60.325 mm That means DN50 = 60.325mm.Similarly for 10 ", NPS 10"=DN250=>As per ASME B36.10 Chart,the OD is 10.750"(273mm).Now we move to the next term which is Schedule that is used in piping repeatedly.

SCHEDULE

Get Full Chart

So far we have learned the OD/size of the pipe,  to know the OD of any pipe, see its NPS, now we will discuss the thickness of the pipe, The schedule indicates the wall thickness of the pipe. The formula that is to be used for this, which we also know by the name of Barlow's Wall Thinks' formula, it is a calculation that is used to show the relationship between internal pressure, allowable stress, nominal thickness, and diameter. The formula is: P = (2xSxt) / D, where: P = internal pressure, psi S = unit stress, psi t = nominal wall thickness, in. D = outside diameter of the pipe, in.

PIPE DATA

A complete pipe data including pipe weight chart,

Click to get

Get a full chart To be continued