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-- Mlloydmequon 17:29, 31 July 2006 (UTC)MikeIs this article a business directory listed at the bottom? is that policy?
31July06: The article is useful as it is. But it suffers a bit from its apparent perspective in potable water distribution. To wit: It omits several important classes of flowmeters:
1) Flowmeters providing visual flow information such as:
a. rotameters with poppets positioned by flow/gravity interaction b. totameters with poppets positioned by flow/spring interaction c. vane type flowmeters
2) Low cost "mechanical" flowmeters
a. paddlewheel flowmeters with pickups using reed switch or Hall effect or optical or ?? sensors b. turbine flowmeters with various pickups
3) Other flowmeter types:
a. Fluidic oscillation meters (related to vortex shedders, but different enough to justify their own mention) b. Target meters (related to pitot meters, but, again, different enough for mention).
4) Beyond this, venturi meters and orifice meters should be classified as "head flowmeters" or something similar. This would then be a reasonable place to include open channel flowmeters such as:
a. V-notch wiers b. Parshall flumes.
I'm sorry that my expertise is not up to the task of providing actual improved text for the Wiki entry. Hopefully, some expert will take my (probably still incomplete) list and use it to extend the entry.
Dear all,
Is that anyone come across this issue before? How does the density or viscosity affect the total flow? for example, with different density of gases, will they have same quantities if their flow with same units (1000 m3/hr, etc)?
Regards,
Lee
Is it really enough to say that a venturi meter constricts flow 'in some fashion'? I believe a venturi flowmeter must use a venturi tube, just as a orifice plate meter must use an orifice of a very specific size in order to function.
Hi
I need help on a formula that I can use in spreadsheet or database to calculate total quantity of fluid passed over a period of time.
Example pressure 25 psi, pipe bore 2 inches, length 12 feet, fluid = water time 20 minutes.
I would appreciate an answer from anyone who can spare the time please
Nb I would be using MS Excel or Access (sad I know but limited resources).
Thanks
Allan
Unfortunately Allan, the calculation isn't as simple as your question implies.
The simplest equation for calculating flow looks like this:
V = Av
where:
(V) is the Volumetric flow rate (in your example, probably in cubic feet per minute [cfm])
(A) is the cross-sectional area of the pipe. In your example the area would be the pipe radius (half the diameter or 1 inch) squared times pi (3.14) or 3.14 square inches. For most flow equations in standard units, you will want the area of the pipe in square feet, which in this case would be 0.0218 square feet.
(v) is the average fluid velocity. This is where your example gets harder. The flowmeters in this article really only measure fluid velocity because the pipe size (and thus the cross-sectional area) is fixed by the meter itself. If you don't know the fluid velocity in your example, you can't calculate flow. If we could measure flow with the example information you provided, flowmeters would be unnecessary, you could measure flow with a pressure gauge and a tape measure.
However let's say you did know the velocity, and you didn't list it because you didn't know it was important. Lets say for example it's 20 feet per second (fps). The volumetric flowrate would be 0.0128 square feet times 20 feet per second or 0.256 cubic feet per second. Cubic feet per minute is a more standard unit of measure, so converted that would be 15.36 cfm.
There are 7.48 gallons in one cubic foot of water, so in gallons per minute (gpm), that is 15.36 times 7.48 or 114.9 gpm.
If it was mass flowrate that you wanted, the above equation is still necessary. The following equation is then applied:
m = Vρ
where:
(m) is mass flowrate
(V) is volumetric flowrate from above
(ρ) is the density of the fluid (in this case water)
Density of pure water is a function of temperature. If the temperature of the water in your example is constant and known, you could look up the density on a table. For now, we will use 62.3 pounds per cubic foot, which is the approximate density of water at 70°F.
Using the volumetric flowrate we calculated above, the mass flow rate would be 15.36 cfm times 62.3 pounds per cubic foot or 956.928 pounds per minute.
After you calculate the flowrate the rest is the easy part. Take the flowrate (we'll use the 114.9 gpm from above) and multiply it by the time that has passed to get total volume. From your example we will use 20 minutes times 114.9 gpm and we see that a total of 2298 gallons of water have passed through our 2 inch pipe in the 20 minutes alloted.
Although I'm sure this entry didn't get you closer to your spreadsheet equation, I hope it shed some light on flow calculation in general, as well as the variables required to calculate flow.
Brandon W.
Dear Brandon Kindly let me know if the medium is air for the above what would be the flow if the input pressure is 6kg/cm2 and the does the size of the pipe matter and what is the relation. If an orifice is used in the valves what effect does it make. I have an enclosure of say 50cuft and would like to purge out 100cuft of air with a 6kg/cm2 pressure air with me what would be the size of the tube at inlet /outlet and what would be the time required for the same.
Pramod
How would an instrumentation engineer differentiate between the measurement of flow and pressure? Plz help —The preceding unsigned comment was added by 61.0.17.157 ( talk) 02:00, 3 April 2007 (UTC).
Wikipedia is not a place for advertising. I took out an enormous quantity of far-too-specific text and pictures with a whole bunch of registered trademark logos on it. The information duplicated other info that was found in the rest of the article, was way too specific, linked to proprietary websites and generally looked like a paste from a company representative. I re-worked what I could but most of it I just took out. WLU 20:15, 18 July 2007 (UTC)
how to find the required diameter of pipe if we know discharge,velocity of flow and density of fluid in sewerge net work —Preceding unsigned comment added by 121.247.154.101 ( talk) 10:59, 9 April 2008 (UTC)
When water needs to be pumped for a distance of 3 kilometers, and a constant pressure of 3 bar is supplied what is the optimal diameter of pipe that can be used? What formula can be used to calculate the diameter of pipe to be used when the pressure substance (water) and distance are known. Can anyone provide me with information? Arjaa ( talk) 09:14, 4 August 2008 (UTC)
1. Explain the difference between a quantity metre and a rate-of-flow – flow metre. —Preceding unsigned comment added by 122.55.116.49 ( talk) 07:38, 29 July 2009 (UTC)
Why does the text use "flow meter" instead of "flowmeter"?. There are lots of instances where concatenating the word "meter" with the preceding noun is common i.e. calorimeter, odometer, speedometer, ammeter, barometer, anemometer, velocimeter, etc BluesLewis ( talk) 01:19, 11 December 2011 (UTC)
Updated the information on ultrasonic flow meters to make it clear that Doppler and transit time are two separate methods. Also reduced the marketing spin about natural gas (these technologies are used for so much more). I will be updating the Ultrasonic flow meter page shortly for similar clarity issues. AussieMueller ( talk) 20:16, 23 April 2013 (UTC)
One commonly-used method of verifying the accuracy of a liquid flowmeter (particularly if the liquid is water) is to let the liquid flow at some measured flow rate into a bucket for a specified period of time, and then weigh the liquid (taring the bucket, of course). Mass of liquid divided by time is the mass flow rate. It's extremely low-tech, but can yield surprisingly good accuracy. Accuracy can be improved by increasing the flow time - this reduces errors due to reaction time with the stopwatch, but you need a bigger bucket and scale. 152.51.56.1 ( talk) 13:48, 14 June 2013 (UTC)
" The density for a liquid is almost independent of the liquid conditions; however, this is not the case for gas, the density of which depends greatly upon pressure, temperature and to a lesser extent, the gas composition."
There is so much wrong in this statement. First of all saying density of liquid is almost independent of the conditions is wrong. Density of water changes ~4% between 0 - 100 degree Celsius, how is that not a significant change? It would be right to say relatively less dependent compared to gas. Second density of gas is depends to a lesser extent on the gas composition. What does this even mean? This implies if i mix gases its density doesn't change, which is completely wrong. Changing a fixed volume of pure hydrogen to same volume of 50% hydrogen and 50% Argon increases is density by 40 times. Ray Lightyear ( talk) 14:24, 14 June 2013 (UTC)
I think that section confuses MAFs and AFMs (Air Flow Meters) which measure volume rather than mass. The two specific examples I'm aware of are moving-vane type AFMs which incorporate a temperature sensor so that the engine control module can calculate air mass from the measured volume and temperature; and a heated-wire type MAF which measures mass directly by determining the current necessary to maintain a platinum wire suspended in the air stream at a predetermined temperature. Dbeierl ( talk) 04:05, 8 July 2013 (UTC)
The section "Turbine Flow Meter" mentions a phenomenon called "Dog mix interference" which only appears on Wikipedia and copies of Wikipedia articles...and nowhere else. I'm virtually certain it's a translation error, but am unsure what to replace it with. Turbulence?
(The only other place I can find that isn't a copycat article is Water metering#Turbine meters, which is pretty obviously a copy-paste from this article, or vice versa)
Cicero225 ( talk) 17:36, 2 April 2014 (UTC)
I've copied the following from my talk page, where it was posted under the heading "flowmeters and reliable sources", so that the discussion is kept with the article and other editors can join it. NebY ( talk) 19:40, 28 December 2015 (UTC)
Dear NebY,
Thank You for your attention.
I must take issue with several things.
First, I suggest that the class being referred to as 'linear resistance meters' is too easily confused with apparatus for measuring ohmic resistance. I suggest returning to 'Viscometric flow meters' and moving the somewhat hypothetical 'multi-tube', and porous element meters to their own sub-classifications of 'pressure differential types'.
Also, I don't see the point of pointing out that a longer tube yields a larger pressure differential, this is evident from the equation. Indeed, a reason the viscometric flowmeter became viable was improvement in technology to take reliable and inexpensive low differential voltage measurements, which correspond with shorter sensing elements. Indeed, shorter elements are preferred since they do not induce as great a pressure drop in the system as would a longer element.
Also, these devices are not restricted to 'very low flows', and are not restricted to laminar flows except in the special case of those 'pressure differential' types which do indeed use the Hagen-Poiseuille relationship.
Also, I'm not sure why the US Patent office does not classify as a reliable source. Seems independent, rigorous, and staffed by reasonable subject matter experts. On further research, I see how to properly cite a patent as a sounrce here: /info/en/?search=Template:Cite_patent
Also, there is the 'viscometer', and there is the 'flowmeter', and there is a 'viscometric flow meter', which performs either function at a given time.
Also the last edit seem to infer flowmeters using "a bundle of such tubes, or a long porous plug" are governed by the Hagen-Poiseuille relationship, and this is not the case.
Lastly I suppose I would say it is somewhat misleading to characterize the viscometric flowmeter as having a similar temperature related error characteristic as the super-set of linear resistance meters, as viscometric flow meters specifically measure and compensate for temperature variation over some range. This is the charachteristic which separatesthem non-temperature compensated implementations.
Please advise. Regards, Herr baumeister ( talk) 02:52, 21 December 2015 (UTC) Herr Baumeister. — Preceding unsigned comment added by Herr baumeister ( talk • contribs) 02:21, 21 December 2015 (UTC)
Italic comments/rebuttals/etc inline with below are from Herr baumeister in response to NebY's edits of the section on 'Linear Resistance Meters'.
Dear NebY, First with regard to a technical error about increasing the tubing length and the associated pressure induced flow error....... The actual flow of any device under test does change as a function of backpressure (hydraulic loading). Contrary to what we were taught, fluids compress. Additional backpressure due to a measurement device having a longer (rather than shorter) flow sense tube (given identical radius) will cause additional compression of the fluid, changing mass in a given volume of fluid. For this reason, regardless of the source (cited does not necessarily mean correct) I removed your insertion regarding the suggestion to improve resolution by increasing tube length. The tube selection based on modern instrumentation sensitivities is the correct engineering approach. Second, the previous edit separated the single tube 'viscometric' flowmeter from the other types which were introduced and wrongly asserted as conforming to Hagen Poiseuille. Therefore, it made sense to separate the single tube laminar flow device from the multi-tube and porous element types. Additionally, the single tube type (viscometric) can indeed directly calculate viscosity in traditional units, based strictly on Hagen Poiseuille, whereas the other types (multi-tube and porous element) cannot. So it seems entirely appropriate to create a sub-class of linear resistance measurement types. Last, Regarding patents as sources, though patents are not included in or excluded by the Wikipedia policy, and since Wikipedia policy acknowledges that even among scholarly sources there is a variety of robustness of review, one could reasonably argue within the interest of providing additional sources of study that an abandoned patent has a reasonable chance of furthering a readers knowledge without chance of providing falsehoods......at least no greater chance of promoting what is false than any other type of citation. I ask what is a citation fundamentally? They are not by any means validation and proof of truth. One must follow the citation and ultimately make various judgements. Since policy regarding patents is not in the guidelines, I suggest this topic of truthfulness and reliability of citations, particularly as specific patents compare to currently accepted citations, be forwarded to the appropriate Wikipedia policy body.
Rebuttals/comments to immediate previous post above added in italics.
Herr baumeister ( talk) 01:49, 29 December 2015 (UTC)Herr baumeister
Advantages and disadvantages of orifice meter and venturi meter and Differences between venturi meters and orifice meters are strange titles for free-standing articles. Any unique salvagable content should be brought to this article. -- Wtshymanski ( talk) 18:33, 22 October 2017 (UTC)
The talk page at Variable area meter suggests a merge with this page. "Variable area meter" essentially duplicates the contents at the section in this article. The link to a seond article isn't helpful here because there's no additional content. -- Wtshymanski ( talk) 19:50, 12 January 2018 (UTC)
Eric Lotze ( talk) 17:11, 4 October 2022 (UTC)