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[doug3030]

Ok lets have a look at the link posted by Bedford in this thread to explain the difference.

[/FONT]edford;1704183]Difference between Pipes and Tubes

"Pipes

The purpose with a pipe is the transport of a fluid like water, oil or similar, and the most import property is the capacity or the inside diameter.

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."


So if pipe is sold by the Inside Diameter, why is a 2" ID pipe either 2.067" or 1.939" depending on whether it is schedule 40 or 80, yet the OD remains constant?
Well of course it is so that schedule 40 and schedule 80 pipe will both fit into the same fittings.

If you ask for 2" pipe neither the ID or the OD are 2". Looks a tad confusing to me

"Tubes

The nominal dimensions of tubes are based on the outside diameter. If we look at Copper Tubes - ASTM B88 the outside diameter of a 2" pipe is 2.125", relatively close to 2".

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 atCopper 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."






So Tubes are made to higher tolerances but a 2" tube OD actually measures 2.125"! So if you ask for a 2" tube neither the ID or the OD will be 2" either.

In summary, tubes are sold by the OD but the OD you ask for is not what you get, and pipes are sold by the ID and the ID you ask for is not what you get either.

If I was in the business of selling this stuff to hobbyists I would not generally expect them to know this stuff. If I was selling to trade then I would expect them to know.

I asked the same questions of major suppliers as well but they were all helpful, and a tad expensive and far away when it came to the offer I got to cut them all to length.

I chose not to argue with "Mr Cheese Shop" days ago but it just goes on and on in here.

It is obvious that the ID and the OD are a nominal figure and are not in any single case at all an accurate measurement. It is just a label to give it a name to sell it by and give a rough idea of the size. They could just as easily called a b c d e f etc.

I got exactly what I wanted with the same opening question and was understood by everyone else who I asked about their product.

I am going back to the shed to fit some brass ferrules cit from a brass tube with an ID of approximately half an inch, whether they exist or not.

Cheers

Doug

[FenceFurniture]

I chose not to argue with "Mr Cheese Shop" days ago but it just goes on and on in here.

Maybe I'll get my money's worth after all.

Ten minute argument please, with all the trimmings.

[doug3030]

Maybe I'll get my money's worth after all.

Ten minute argument please, with all the trimmings.

Sorry, you are in the wrong room. It's being hit on the head lessons in here.

Doug

[Bedford]

Without getting involved with shopkeepers etc, one reason tube is referred to by the OD is that it often goes with a matching fitting where the ID is not so critical.

Things like towel rail ends need the correct OD so they fit properly, Towel Rail End Brackets, Economy Range, Chrome from Miles Nelson

And also things like fittings for copper TUBE (that everyone calls pipe!) Copper Compression Fittings With O-Ring - China Copper Fittings, Copper Fittings With O-Ring

[doug3030]

one reason tube is referred to by the OD is that it often goes with a matching fitting where the ID is not so critical.

And yet, as I quoted above, for pipe, where its the ID that supposedly counts:

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."


So the pipe, which is sold by a nominal ID, which is never the same as it actually is, also maintains the same OD over the different wall thicknesses, so that only one size of fittings or ends are needed.

Its the same argument but one is ID the other is OD and neither are accurate.

Its a wonder anything more complicated than my little ferrules ever gets done under this system.

Cheers

Doug

[Bushmiller]

Doug

Really we have only just started. Tube, I think, qualifies for that term when it's wall thickness is of a sufficient thinness . Once the wall becomes suitably thick it becomes pipe, which is then described as, for example 2" NB where the NB stands for nominal bore.

However, if that has made things clear, it shouldn't have done, as it is nowhere near as simple as that. Fortunately, the steel makers produce Steel Mass books. These are not super-powered Jesuit priest hand books, but a pretty good guide to all the steel profiles including inside and outside dimensions as well as weights.

For tube, you can't go past a digital vernier gauge, although I accept it has it's limitations over the phone .

Regards
Paul

[doug3030]

Really we have only just started.

Thats for sure Paul, I have been looking further into some of the stuff on the link Bedford posted. I am not blaming you for the content Bedford. I am just using your name to identify the link, OK?)

To quote:

"Pipes

The purpose with a pipe is the transport of a fluid like water, oil or similar, and the most import property is the capacity or the inside diameter."

Well if the capacity is so important and there is such a big variation in the capacity of a section 40 2" pipe compared to a section 80 2" pipe?

Schedule 40 pipe - ID 2.067" = cross section of 3.3556 square inches

Schedule 80 pipe - ID 1.939" = cross section of 2.9529 square inches

That's a whopping 17% difference in cross section which may result in over 20% difference in volume of fluid that can pass through in a given time under given conditions but they are both classed as nominally 2" pipe - because capacity is the most important factor in pipe which is why it is measured by its ID (but not accurately)

No wonder I asked for tube

Cheers

Doug

[Bushmiller]

No wonder I asked for tube

Cheers

Doug

Doug

If you ever get to grips with tube and want to further your knowledge with pipe, this may help:

http://www.bjhowes.com.au/Know%20You...eel%20Book.pdf

Regards
Paul

[FenceFurniture]

THE SCENE: Man sitting at a desk, staring at an old black 1970s phone on a desk. His hand is at the ready, waiting to pounce on the handpiece.

RING RING

HIM (with authority): “Hollow Metal Cylinders Incorporated, hello”

ME (tentatively): “Yes, I was wondering if you could help me please? Do you look like Michael Palin with a false moustache, spectacles and a white technician’s jacket? Blue shirt, striped tie, and so on?”

HIM (surprised): “Funny you should mention that Sir. I do, as a matter of fact, but only for today, and only while I’m here. I’ve been waiting for your call Sir!. How can I be of assistance to you today?”

ME (surprised, and a little feisty): “Oh good, because I look like John Cleese in a wet suit, with a fish in each hand, which I am prepared to use. (cautiously) I’d like to buy some Hollow Metal Cylinders please”.

HIM (gratified): “YES SIR. What size would you like?”

ME (knowingly): “Oh no you don’t – you won’t trick me like that with your silly salesman’s tricks!”

HIM (bemused and confused): “Beg pardon Sir?”

ME (confidently): “I said your salesman’s tricks won’t fool me. I know exactly what I want!”

HIM (with a slight rise in arrogance): “Glad to hear it Sir. Would you mind telling me what it is that you want?”

ME (needing reassurance): “Well, as long as you don’t laugh.”

HIM (reassuringly, but with choked laughter - already): “No, no, not at all Sir.”

ME (hesitantly reassured): “Alright. I’d like a brass hollow cylinder with an internal diameter of ½”

HIM (confident again): “Yes Sir. Would that be tube or pipe you were after?”

ME (on the ball): “AHA! YOU SEE? Playing games already! I told you, you won’t trick ME! You can call it what you like, but as long as it has an internal diameter of ½” and a wall thickness of approx 1mm then that is what I want.”

HIM (professional): “Hmmmm. I’ll just need to clarify that sir. Yes, you’re mixing Imperial and Metric measurements together, so I’ll ask you to use just one system to avoid confusion – yours and mine, Sir. AND, you really must tell me if the hollow metal cylinder you require is tube or pipe. There’s a difference you know!”

ME (aggravated): “NOW LOOK! I’ve already told you everything you need to know! Do you have a product that matches that description, or not?”

HIM (arrogant): “Well we probably do Sir, but in tube or pipe? I mean it’s a pretty simple question. You do understand the very simple question, don’t you Sir, or should I rephrase it? Yes, perhaps I will - pipe or tube sir?”

ME (confused): “I thought I was John Cleese??”

HIM (apologetic): “Quite right Sir. My apologies! Now then, tube or pipe?”

ME: (gambling): “Ah, I’ll take the, ah, ….just a sec……I’ll take the ….p…. no, the tu…..no, it’s PIPE that I want!”

HIM (confident again): “Ah, excellent choice Sir. I do believe that we may have that in stock!”

ME (relieved): “Well thank kee-rist for that. I thought I was going to order the wrong thing. I happen to know, you know, that tube doesn’t have an internal diameter!”

HIM (indignant): “Yes it does!”

ME (confused again): “What ever do you mean? Just because the inside is circular, it doesn’t mean it has an ID. You know that as well as I do!”

HIM (smartarse): “Ah, that was just a trick to make sure you REALLY knew what you were on about. Well done Sir, I see you know your tubes from your pipes eh? No fooling you sir! May I ask, what did Sir wish to use these Hollow Metal Cylinders for?”

ME (back on my own territory, and confident): “Oh well, I want to make some ferrules, but I guess you don’t know what they are. Yuk, yuk, they have an ID AND an OD, you know! Bet you’ve never heard of that before!”

HIM (to someone in the background): “HEY BERT?! This bloke just wants some Ferrule Hollow Metal Cylinders in Brass. How much have we got?”

ME (indignant): “WHAT? You mean you have an actual product specifically for Ferrules??”

HIM (also indignant): “Well yes of course we do. You only had to ask for it, you know. Sheesh! Tsk tsk tsk!”

ME: (irate now): “Well how the hell would I know that you know what I want? And you're being John Cleese again!”

HIM (perfunctorily): “Well if you said what you mean, instead of playing these stupid games, we could all have a laugh. As it is I’ve had to prise the information out of you. Typical bloody customer. Think they know everything, when all they really know is what they want! Starve the crows, I'm sick of know-alls like you! And WE have to do all the brainwork. I’m thinking of resigning you know.”

ME (completely bamboozled, bemused and amused): “What, because I asked for a specific item, AND got the terminology correct? You're balmy mate!”

HIM (curtly): “That it then, SIR!? Anything else? Hollow Metal Squares with non 90° corners perhaps?”

ME (ineptly controlling laughter): “No, that WILL be all for today. Thank you for your excellent help! OH! WAIT! There is just one more thing. What is the diameter of the outside of these pipes”

HIM (knowingly): “Ah, I see you’re learning Sir! Well done! I thought for a moment there you were going to ask for the Outside Diameter, but we both that pipes don’t have one eh?! The diameter of the outside is of course 14.7mm give or a take 1/128 of an inch.”

ME (relieved): OH FANTASTIC, it’s just the tube I’m after!”

HIM (outraged): “I’m sorry, did you say ‘tube’?”

ME (backpeddling fast): “No, I profoundly apologise! I meant to say pipe”.

HIM (in the knowledge that he has won): “HA! TOO LATE! No way am I selling it to you now! I’d rather eat sandwiches for dinner than sell this t…….pi……hollow metal cylinder to you, YOU FOOL! Goodbye, and don’t call again!”

Beep…beep…beep…beep





Man, I’m glad I didn’t ask why it’s called a ferrule, when it’s made of brass.

[Bushmiller]

Brett

Can I take it there won't be any pipe or tube for sale at the BM GTG 3: Just Oil and glue. Do we bring our own containers and will I get more if it is a large tube container or a large pipe container? Also how much is it to argue the toss? Could I bring Sybil to argue on my behalf? Oh, wait a moment, she might be contracted to a different mob .

You tell a good story .

Regards
Paul

[Sawdust Maker]

Fency

you're a sad sad man!

[rwbuild]

Best laugh I've had all day Fency

[FenceFurniture]

Brett

Can I take it there won't be any pipe or tube for sale at the BM GTG 3: Just Oil and glue. Do we bring our own containers and will I get more if it is a large tube container or a large pipe container? Also how much is it to argue the toss? Could I bring Sybil to argue on my behalf? Oh, wait a moment, she might be contracted to a different mob .

You tell a good story .

Regards
Paul

Well, Mr W. Bush Miller, before we go any further, answer me this: is a Didgereedoo a tube or a pipe?

DO be careful how you answer!

[A Duke]

FF or TT for tripe writer of the year?

[rustynail]

That was obvious but the salesman should have realized this and explained this to help the customer. He could have been helpful and gain a sale. In these times every sale is important and a salesman upsetting a customer will do so at it's peril. Gone are the days that you can treat a customer as an idiot for with the internet one upset customer can, by using YouTube or Facebook, bring a big company down. If this was posted on Facebook it would go viral within the hour.



All I can say that to me that sounds like a load of codswallop for your prejudice seems to be showing.


Peter.

What exactly strikes you as codswallop and what exactly have I said that you find prejudicial?
Every business has, from time to time, had to deal with dissatisfied customers. The manner in which they do this plays a large part in determining their success. To say a salesman upsetting a customer will do so at its peril is not necessarily correct, in that it breaks both ways; the customer upsetting the salesman can also produce a less than desirable outcome. I think both parties have a case to answer and therefore the need for one to ridicule the other is somewhat unnecessary. Why is it that people can't tolerate shortcomings in others, yet sweep their own under the carpet as if they dont exist? Nobody likes criticism, I should know, Ive copped enough of it here. May I suggest, an important character trait is the ability to own your mistakes. None of us are perfect.
We all fall short from time to time, but the ability to accept those short comings in others makes for a better society.
Please, if nothing else, could we agree that pipe is pipe and tube is tube? ID and OD?