The Difference Between Tubes and Pipes

Check here:

http://www.tpatube.org/

Quote:

The difference between pipe and tube is simply in the way it is sized. PVC pipe for plumbing applications and galvanized steel pipe for instance, are measured in IPS (iron pipe size). Copper tube, CPVC, PeX and other tubing is measured nominally, which is basically an average diameter. These sizing schemes allow for universal adaptation of transitional fittings. For instance, 1/2" PeX tubing is the same size as 1/2" copper tubing. 1/2" PVC on the other hand is not the same size as 1/2" tubing, and therefor requires either a threaded male or female adapter to connect them.

from: http://en.wikipedia.org/wiki/Water_pipe

One rule of thumb is if it's small or flexible enough to easily fit into any of your body's orifiaces, it's a tube. Otherwise, it's a pipe.

Oops, I meant:

One rule of thumb is if it's small or flexible enough to easily fit into any of your body's orifices (except the mouth) , it's a tube. Otherwise, it's a pipe--hence, rule of thumb.

Does that mean that my girlfriend has got a tube in her beside locker ?

Beside locker?? Is that where she keeps her pipe?

That makes sense.

IPS (Iron Pipe Size) is a nominal dimension which approximates the actual ID of standard (Schedule 40) pipe. However, the ID is greater for lighter schedules, and less for the higher schedules (viz. Schedule 80, XXHY, etc.) because of the difference in wall thickness. For iron pipe, the outside diameter remains constant. This means that any schedule of threaded iron pipe of a nominal size will mate with a fitting of the same nominal size, if the thread is the same.

Here's a table: http://www.bakersfieldpipe.com/pipechart.html

The words "pipe" and "tube" are almost interchangeable. The use of one word or the other is determined more by convention or individual preference than by any intrinsic difference between the two.

Refrigeration pipe sizes or in O.D..Plumbing pipe sizes are in I.D. the same tubing is used but the fitting sizes are measured differently.

Just a week back we had a thorough discussion on this subject

http://cr4.globalspec.com/thread/31577

pl check the previous threads. Why repeat the same subject ?

Why repeat the same subject ? -because some people have little else to do, they just love to hear the sound of their own voice (or in this case the tapping of the keyboard). I bet if I posted this question next week that I would get the same responses.

And a year back we had:- http://cr4.globalspec.com/thread/11077 which went into great detail, great detail, great detail! There's a hell of an echo around here!

The strange thing is that some of the original commentators from a year ago have changed their views on the subject today! Now why would that be?

Hi all,

One difference as I understand is that the tube can have any section, (square, elliptical ans son on)...the section for the pipe will be always a circle.

Regards

Ernesto

Wher can I find my conduit?

Seeing as how the OP was posted in The Instrumentation Section, now I'm wondering whether or not you've all been had!

Dear Shiha,

In a pipe, you transfer fluid along its lenth.

In a Tube, you transfer Heat through its thickness.

Regards,

Sayed Sarhan

Its acturally quite simple.

Pipe size is based on internal diameter (ID). For example a 1 inch pipe has an ID of 1.049 inches.

Tubing size is based on outside diamter (OD). For example a 1/2 inch copper tube actually has a 5/8 inch outside diameter.

I hope this helps.

I think your example of tube only serve's to confuse!

Tube of 12mm has an OD of 12mm!

I think that your tube of 1/2" size with 5/8" OD was either PIPE or 5/8" Tube!

Foul! The answer given begs the question; hence is fallacious. Consider: how would you distinguish a pipe from a tube if having nothing (else) but a measuring instrument by which to be guided?

The pipe size dimension is the accepted industry designation, not the actual measured size. To determine pipe size, measure the outside diameter (OD) of your pipe. If the unthreaded pipe OD measures 1.90", the corresponding pipe size is 1 1/2". Unlike pipes, the measurement of a tube (ie 2") corresponds to it's outside diameter (OD). So the outside diameter of a 2" tube is truly 2".

Apart from that, the term "tube" usually has a connotation of flexibility, even though tubes can be made of metal and rigid plastic. Pipes, on the other hand, are not generally thought of as being flexible, even when made of materials that do bend.

In Instrumentation mostly use tubing that size is 6mm, 8mm, 10mm, 12mm,14mm and also use 1/2" pipe also .But the difference between them consider the pipe OD(Outer diameter) and for pipe concider inner diameter.

Sorry mate, don't understand your comments at all. Have you made some typo's?

Tubing is relatively soft and malleable. Pipe is relatively hard and non-maleable.

Tubing is relatively soft and malleable.

How can that be when it is STRUCTURAL! Some high pressure hydraulic tube requires powerfull benders. Box tube isn't soft and malleable either, or is it? Perhaps thats why my trailer snakes along behind my car!

The use of the words pipe and tube are very vague. Now for example, in instrumentation, tubing is used to transfer the system pressure to the transducer. This tube is somewhat malleable and easily manipulated(alot of frustration from non instrumentation workers carelessly stepping on and crimping/bending.). In another case, for building construction piping is used to contain a fluid (water,gas, etc.) while tubing is used as a structural element. In this case the tubing can be round, square, or what ever shape that it has been made into per the design specification (Asked my Architectural Engineering pal).

So, we see that the definition of words will depend upon the industry that it is used in. So let's not get all uptight about this and for further post to this Forum (It is Instrumentation Forum, isn't it?) Tubing will used to connect instruments to process pipes.

So after three separate discussions on the subject, spread well over a year with over two hundred individual contributions, the jury is still out! Perhaps this is an un-answerable question.

I don't think that, where this discussion is posted (Instrumentation) should make any difference to it's outcome!

I beg to differ. Due to the various definitions for the same word in the English language, the context that a word is used in does matter. Otherwise, we would never know what is being talked about. (I don't want this to turn into an English usage debate, this thread has been beaten to shreds.)

As with the spirit of this website, everyone is entitled to their opinion and can freely voice it. In matter of fact, I welcome it.

It's answerable. I stand by mine (post #22) and I see several others say about the same thing.

There is only one remarkable difference between PIPE and TUBE.

It is, TUBE can have c/s other than circle but PIPE c/s shall be only Circle. Rest all explanations will hold same for both PIPE and TUBE.

Regards,

Sabir