Type of flowmeter for large water pipe

[birkATO]

Would anyone have a recomendation for the type or perhaps even a brand of flowmeter to install in a particular applicaiton? The pipe is 20" and 30" steel pipe pumping water at a rate of 2000-5000 GPM. The site happens to be fairly remote. Power is available, but no buildings. I am a little bit familiar with how magnetic flowmeters work, but have never installed one or sized one up for a particular application. Would this type of meter be a good choice? Would a nonconductive section of pipe have to be spliced in to make it work? Maybe there are cheaper options. I'm just looking for a starting point or any helpful pointers. Thanks!

 

[Latexman]

Looking for a starting point on a 20" / 30" water line? Google "mag meter" and contact a vendor. They'll be glad to get you started for that large of a meter. A nonconductive section of pipe is not required. Your water just has to be conductive, > 1 micro mho if I recall correctly.

Good luck,
Latexman

 

[Ashereng]

We have used wedge meter for crude oil at 700 m3/h (3080 USGPM). It works well. Low tech. You have power. Your turndown is about 3:1 so this seems a good fit.

Ultrasonic works well. The clamp-on type are really good if you need to service or replace. Dependin on accuracy required of course.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[stanier]

Magnetic flowmeters would be ideal if you wanted tiht control or custody transfer. For general flow data & chemical injection you may consider ultrasonic flowmeters as they are less costly and are adequate for the water industry.

Geoffrey D Stone FIMechE C.Eng;FIEust CP Eng

http://www.waterhammer.bigblog.com.au

 

[quark]

Annubar(averaging pitot tube) can be a cheaper and better option. Excellent for 3:1 turndown and can work upto 9:1.

Check with Fischer Rosemount. I saw Annubars working even for custody transfer application.

 

[jmw]

Insertion mags are very affpordable.
You could try Peek (now under Thermo electron?) who even provide mag meter solutions for open channel (river) flow measurements or an insertion turbine or vortex... try your seach with "insertion" and you get a large range of manufacturers to sort through looking for one that does your size... typically in the $1500 to $3000 price range.
This one, for example:

http://www.seametrics.com/flow_meter/agEX100.html

JMW

http://www.ViscoAnalyser.com

 

[Latexman]

Ashereng,

Is "wedge meter" the same as vortex shedding meter?

Good luck,
Latexman

 

[Ashereng]

Latexman,

No. Vortex shedding meter is a vortex shedding meter.

A wedge meter is a DP meter. Instead of a orifice, for example, there is a literal "wedge" or simiilar engineered constriction in the pipe. This also creates a pressure drop, though not as much of one as an orifcie. Hence, usually used in larger flowrates. The wedge is usually only on one side of the pipe.

Here are links with good schematics:

http://www.preso.com/resources/tech/COIN_Instructions8.5-11Rev2.pdf

http://www.solartronisa.com/products/primaryflow/wedgeflowmeters.php

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[rconner]

Not claiming to be an expert in this field but for whatever reasons I have seen at least some significant water utilities over the years also employing "venturi" type meters for measuring water flow in often quite large pipelines. These particular meters themselves are typically quite large (and I suspect are often by far NOT the "cheapest"!)and also occupy/require some notable length of piping -- you may be interested in the site at

http://www.inh2o.org/Articles/WaterArticles/1_Purpose_of_meters.pdf

it appears discussing advantages/disadvantages of many different types of meters.

 

[Alanator]

McCrometer makes a V-cone flow meter. It is a differential type that has a cone placed in the flow stream. This helps to condition the flow, so the flow meter does not require a lot of straight piping upstream/downstream.

 

[stanier]

I agree with Randy Conner, Venturi meters are very common in large pipes. They are easily maintanined as the presure translitter is external. If you have a magflow and need to remove it you have to shut down the pipeline. You may then need a bypass if the water supply is critical.

Geoffrey D Stone FIMechE C.Eng;FIEust CP Eng

http://www.waterhammer.bigblog.com.au

 

[jmw]

Hot-tap insertion would be the next bet if you want to go with mags or vortex or turbine... actually there are some nice insertion turbines out there.
In other words, there are lots of options and it now depends on finding the balance of features/costs/benefits.

JMW

http://www.ViscoAnalyser.com

 

[Ashereng]

Due to the remote site - and by extension, I am assuming 2 visits a year? - I would go with something that needs little to no maintenance between visits.

Clamp on ultrasonic is immune to what is inside the pipe. If you cover the outside with a box, it is well protected.

A DP with diaphram seals is also good to protect against stuff getting clogged, from junk in the fluid.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?