difference between pipe and tube

zola25 · **Joined:** Tue Aug 31, 2010 3:47 pm **Posts:** 14

what is the difference between pipe and tube?

please give your opinion.

sooeey2u · **Posted:** Fri Nov 12, 2010 9:44 pm

For a ASME/ANSI B 36.10 Welded and Seamless Wrought Steel Pipe the inside diameter - ID - of a NPS 2 inches pipe with

•schedule 40 is 2.067"
•schedule 80 is 1.939"

The inside diameters are close to 2" and the nominal diameter related to the inside diameter. Outside diameter are 2.375" for both schedules.

Since the outside diameter of a single nominal pipe size is kept constant the inside diameter of a pipe will depend on the "schedule" or the thickness of the pipe. The schedule and the actual thickness of a pipe varies with the size of the pipe.

The tolerances are looser to pipes compared with tubes and they are often less expensive to produce.

The inside diameter of a tube will depend on the thickness of the tube. The thickness is often specified as a gauge. If we look at Copper Tubes - ASTM B88 the wall thickness of 0.083"of a 2" pipe is gauge 14.

The tolerances are higher with tubes compared to pipes and tubes are often more expensive to produce than pipes.

Dr. Koelbl · **Posted:** Sat Nov 13, 2010 1:37 pm

In ASME: The difference is the use:
Pipe is used for fluid transport: feedwater pipe, main steam pipe, NPS1" nozzle pipe
Tube is used for heat transfer: HX tubing, Superheater tubes.

In London the subway is called "the tube".

DK

zola25 · **Joined:** Tue Aug 31, 2010 3:47 pm **Posts:** 14

Dr. Koelbl wrote:

In ASME: The difference is the use:
Pipe is used for fluid transport: feedwater pipe, main steam pipe, NPS1" nozzle pipe
Tube is used for heat transfer: HX tubing, Superheater tubes.

In London the subway is called "the tube".

DK

in heat exchanger, pipe is use as spacer (spacing between baffle to baffle)...any clarification?

Dr. Koelbl · **Posted:** Sun Nov 14, 2010 5:51 pm

Zola,

The pipe and tube definition depends on the INTENDED use, also with respect to sizing by the material manufacturer.
ASME COde allows to use pipe also for HX, tubes for transport of fluid. But please note there are different material specs, like SA-312, SA-213.

DK

mkp · **Joined:** Wed Aug 03, 2011 1:05 pm **Posts:** 3

Apart form application there is also difference in Geometrical shapes.
Pipe = Round.
Tube = Square, rectangular, Hexagonal.

Pipe - OD constant
Tube - Defined on ID basis

sooeey2u · **Posted:** Wed Aug 03, 2011 4:36 pm

Tube is also round in shape...

lordsteel · **Joined:** Wed Aug 10, 2011 4:20 pm **Posts:** 18

I think we shall refer to ASTM or ASME standard.
In the standard, you can obviously see what is used for tube and what is used for Pipe.
And the answer is open, i also agree some of opinions in this topic.
I attached standards for tube and pipe, if you like, you can refer it.

epipeinfo · **Joined:** Tue Dec 21, 2010 1:47 pm **Posts:** 2

Pipe is always round in shape and open at both ends but tube always close at one end at other end is always open.

kotharilm · **Posted:** Mon Nov 07, 2011 3:10 am

epipeinfo wrote:

Pipe is always round in shape and open at both ends but tube always close at one end at other end is always open.

Tube is used for mass transfer
If mass is not transferd mean pipe for small size

Thanks & Regard
Lalit Mohan Kothari
TUV-NORD Delhi,India

difference between pipe and tube

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