# How much water in a copper tube?

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• posted on March 15, 2005, 6:05 pm
I am putting a tankless gas water heater in my home. All of the copper is in the concrete slab so I am going to run an insulated copper tube "up and over" to the kitchen. The water heater will be a foot from the two bathrooms and showers. the "up and over" tube will feed the kitchen sink and dish water - nothing else.
How much water is in a 100 foot by 1/2 inch copper tube? How much water is in a 100 foot by 3/4 inch copper tube? How much water is in a 100 foot by 1/4 inch copper tube?
I am too lazy to look it up - I am wondering if any of you experts on here have the info off-hand. I am thinking of putting thinning tubing to the kitchen because less water would be in it to cool down etc.
Right now I am running two 50 gallon electric water heaters in a house for two adults - I am wasting alot of energy keeping all that water hot - and the tanks are far away from where the hot water is needed anyway running thru a cold concrete slab.
Harry

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• posted on March 15, 2005, 6:16 pm
Harry Everhart wrote:

I found a formula for the different sizes on google.

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<%-name%>
• posted on March 15, 2005, 6:27 pm

ID x ID x .7854 x length = volume
[231 cubic inches = 1 gallon = 128 ounces]
Rich http://www.garage-door-hardware.com

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• posted on March 15, 2005, 6:33 pm
Harry Everhart wrote:

I made up a little spread sheet. It assumes 1/32" wall on the pipe.
OD    ID    Area    cu-in    cu-ft    cu-ft              per ft     per ft     per 100 ft 0.500    0.469    0.173    2.071    0.001    0.120 0.750    0.719    0.406    4.869    0.003    0.282 0.250    0.219    0.038    0.451    0.000    0.026
I had to replace the copper pipes in my slab. I ran the new ones in a channel chiseled in the slab to get passed doors. For the heating system, I used 3/4" thick-wall copper pipe and wrapped it in duct tape to prevent future corrosion. The fresh water runs are 3/4" to laundry and kitchen, and 1/2" for the rest. The run to one bathroom is approximately 75 feet. It takes about 30 seconds to start getting the hot water at the end.

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<%-name%>
• posted on March 15, 2005, 7:03 pm

Pipe is measured by ID, not OD. Tubing is measured by OD.
Wayne

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<%-name%>
• posted on March 15, 2005, 9:46 pm
Wayne Whitney wrote:
wrote:

pipe.
That is a common misconception Try taking a ruler to 1/2" nominal Schedule 40 pipe sometime.
Pipe of the same nominal size is the same OD regardless of schedule, but the nominal size is always less than the actual OD, and usually less than the ID too. It may be that the nominal sizes were established by taking the ID of schedule 40 pipe and subtracting some nominal allowance for accumulated scale but I have never seen that in writing anywhere.
However tubing IS measured by the OD and the nominal size is the same as the OD.
--

FF

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• posted on March 16, 2005, 12:06 am
snipped-for-privacy@spamcop.net wrote:

but not the same regardless of material. E.g. nominal 3/4" steel, copper, PVC, and CPVC pipe are different sizes.
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

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• posted on March 16, 2005, 3:20 am
Doug Miller wrote:
snipped-for-privacy@spamcop.net wrote:

3/4" schedule 40 steel pipe has an OD Of 1.050" and a wall thickness of 0.113" for an ID of 0.774".
See:
http://www.interpipe.com/Pipe_Dimensions_and_Weights.htm http://www.gkctcc.com/pipe_dimensions.htm or http://www.inter-mountain.com/line_pipe.htm
(all good sources)
3/4" schedule 40 PVC pipe has an OD Of 1.050" and a wall thickness of 0.113" for an ID of 0.774".
http://www.pvcplus.com/PVC%20schedule_40_&_80_pipe.htm
Looks the same to me.
I didn't check on other materials but it appears that ASTM D-1785 codifies the dimensions. That'd be the place to see if the standards vary by material.
--

FF

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• posted on March 16, 2005, 12:40 pm
snipped-for-privacy@spamcop.net wrote:

[snip]
Quick measurements of actual pipes in my basement shows the following ODs for nominal 3/4 pipe: galvanized steel 1.060 sch 40 PVC 1.055 black steel 1.030 sch 40 CPVC 0.885 copper 0.875
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

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• posted on March 16, 2005, 9:17 pm
Doug Miller wrote:
snipped-for-privacy@spamcop.net wrote:

schedule,
ODs for

I'll bet the copper 'pipe' is actually 7/8" rigid copper tubing. Perhaps the same is true for the CPVC. Are they labeled ASTM D-1785 3/4" schedule 40?
--

FF

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• posted on March 16, 2005, 8:20 pm

So what's your point? 1/2" sched 40 is .680" OD. I think you are confusing mechanical tubing with sched 40 pipe.

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• posted on March 16, 2005, 9:11 pm
bill a wrote:

[that pipe is measured by ID, FF]

My point is stated in the article. I'll repeat it now. Pipe is not measured by ID. It is measured by OD and wall thickness.

No, I am not.
--

FF

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• posted on March 17, 2005, 2:02 pm

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<%-name%>
• posted on March 17, 2005, 5:29 pm
bill a wrote:

Dear Mr Troll:
The OD for 3/4" schedule 10 pipe is 1.050". The OD for 3/4" schedule 40 pipe is 1.050". The OD for 3/4" schedule 80 pipe is 1.050".
The ID's are different for each.
--

FF

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<%-name%>
• posted on March 18, 2005, 4:19 pm
snipped-for-privacy@spamcop.net wrote:

Why did you not say that the OD for *1.050* schedule 10 (or 40 or 80) pipe is 1.050" ? Because to most of the plumbing world (and yourself), it's known as 3/4" nominal ID pipe, not 1.050 OD. Are we arguing over how a pipe is "measured" or "sized" vs. how it is "named" or "called"? How are we to reconcile that 3/4" pipe is named for its nominal ID, yet it is hardly ever called 1.050" pipe, unless it is called by something for which it is "measured"?
Because the ID was the most important characteristic in terms of determining the pipe's resistance to flow, water pipe was named for its ID. The 3/4" pipe size was thus established by some 'primordial 3/4" ID pipe' whose OD turned out to be 1.050". When they made pipe with other wall thickneses, for the sake of compatibility with existing fittings (and dies) which thread onto the OD, they varied the ID slightly to be able to keep the OD constant. Nevertheless, they persisted in calling it by its nominal ID.
However, some types of tubing were always named for their OD, thereby avoiding this whole mess.
%mod%

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<%-name%>
• posted on March 18, 2005, 6:34 pm
snipped-for-privacy@worldnet.att.net wrote:

yourself),
No, not to me. Further, I have never heard anyone else refer to pipe that way either. It is referred to as I did above, by nominal size and schedule. '3/4" nominal ID pipe' is an oxymoron. Nobody calls it '3/4" nominal ID pipe. They call it '3/4" pipe', or '3/4" schedule 40 pipe', or whatever schedule they are using.
They are all 3/4" pipe. I've never heard anyone refer to pipe as 'nominal pipe', 'nominal ID pipe', or 'ID' pipe.
The nominal size for pipe does NOT corresond to a specific ID, it corresponds to a range of IDs. Without knowing the schedule you cannot determine the ID for pipe from the nominal size. However if you know the nominal size you do know the OD, that is unambiguous. Therefor to say that pipe is 'sized by ID' is wrong.
? Are we arguing over

"called"?
yet
something
Again, pipe is not mesured by ID and it is never called 'nominal ID' or even 'nominal' either. 3/4" pipe is called 3/4" pipe, understood to be schedule 40 unless otherwise specified and also understood to have no dimensions equal to 3/4" unless the speaker or the listener does not understand pipe.

its
ID
other
be
I suspect, though I cannot verify this, that nominal pipe sizes were established by taking the actual ID and subtracting an allowance for accumulated scale (corrosion allowance). Since I haven't verified that, I didn't suggest it befor now. I think my GUESS is as good as yours. The fact is that for any given nominal size AND schedule the standard SPECIFIES the OD and the wall thickness, from which the ID may be calculated. Without knowing the scedule you do not know the ID. Pipe is not sized by ID.
Further, if you are doing a flow calculation, as I have, you will use the ID appropriate to the schedule and not a 'nominal' ID.
The actual ID for schedule 40 pipe is ALWAYS larger than the nominal size so calling it nominal ID makes no more sense than calling it nominal OD etymology notwithstanding. Adding 'ID' or 'OD' to the word 'nominal' does not convey any additional information and may, in fact, mislead people as to the dimensions of the pipe.

And I have not, as someone suggested, confused tubing with pipe.
--

FF

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<%-name%>
• posted on March 18, 2005, 6:48 pm
snipped-for-privacy@spamcop.net wrote:

For a given material, perhaps. As a general rule regardless of material, definitely not: 3/4" steel, copper, and CPVC all have different OD.
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

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• posted on March 18, 2005, 10:56 pm
Doug Miller wrote:
snipped-for-privacy@spamcop.net wrote:

material,
After writing this:
I was so sure you were confusing pipe with tubing that I almost didn't look for this:
http://nrha.web-pros.com/How-To/plumbing/copipe/copper.htm
Amusingly enough the actual ID for copper tubing is ALSO larger than the nominal size.
Copper and CPVC pipe indeed is made to a common dimentional standard that is different from the ASTM standard for steel, SS, or PVC.
E.g. Two standards, ASTM D-1785 for steel (including Stainless), and PVC, but ASTM D-2846 for copper and CPVC.
However, it appears that ASTM d-1785 refers to PIPE while ASTM D-2846 refers to TUBE, and the sources for CPVC refer to it as CPVC PIPE in copper-TUBE sizes and far too many sources on the web use the terms pipe and tube interchangeably for copper and CPVC. E.g. according to THOSE people, pipe IS tube for copper, regardless of the meaning of 'is'.
SO I think I'll stick with my earlier contention that the copper and CPVC in your basement are TUBE (though 3/4" tube, not 7/8" while the galvanized and black steel, and the PVC are PIPE for those of us who distinguish between the two.
This looks like it might be a very good source:
http://www.pipefitter.com/Pipedatabk.html
--

FF

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<%-name%>
• posted on April 15, 2014, 9:11 am
On Thursday, March 17, 2005 10:29:15 AM UTC-7, snipped-for-privacy@spamcop.net wrote:

================================================================ Dimensions and Physical Characteristics of Copper Tube: TYPE K 3/4" has a .875 Outer diameter...inner .745
Dimensions and Physical Characteristics of Copper Tube: TYPE L 3/4" has a .875 Outer diameter...inner .785 .251 CONTENT PER FT
Dimensions and Physical Characteristics of Copper Tube: TYPE M 3/4" has a .875 Outer diameter...inner .811 .269 CONTENT PER FT
Dimensions and Physical Characteristics of Copper Tube: Medical Gas, K and L 3/4" has a .875 Outer diameter...inner .785 .336 CONTENT PER FT
Dimensions and Physical Characteristics of Copper Tube: ACR 3/4" has a .750 Outer diameter...inner .666 .242 CONTENT PER FT
(ACR)Copper tube for air-conditioning and refrigeration field service is designated by actual OD, outside diameter.

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• posted on April 15, 2014, 1:08 pm
On 4/15/2014 5:11 AM, snipped-for-privacy@gmail.com wrote:

Nine years later, did we find answer?
--
.
Christopher A. Young