WOOT! I got me a flowmeter!
 

Check it out!

"BLUE WHITE" Flometer
model#: F-44500LH-8
Flow range: 0.5 to 5.0 gpm

(It's my first flowmeter, pardon the excitement!:D :D :D )

ah Null-A Ben, welcome
your first flowmeter lesson

it is interesting (distressing ?) that their instructions do not give the device's head loss curve, but they no doubt have one if you request it

also they do not specify the straight pipe length required on the inlet and discharge side
(Brooks recommended 1.5' inlet and 1' for the discharge for the unit I had)

yes Null-A Ben, that is where I started too (oh so long ago it seems)

report back, eh ?

Duly noted, kind sir! (I'll certainly read over the installation manual very carefully)

When I saw the relatively small size of the marker, and considering that the connections are 1/2 NPT, I assumed that the headloss through it wouldn't be too great. The entrance is pretty narrow, but it is short.

The website was quite useless:
http://www.cie-inc.com/Manufacturers...f440_specs.htm

I found most of the info here:
http://www.kingsolar.com/catalog/mfg...f44500lh8.html
(note how the picture is incorrect)

This 1 page PDF confirmed the flow range for me:
http://www.fabcoplastics.com/catalog/section4/4-15.pdf

as did this page:
http://www.burtprocess.com/phplus/pr...m&series=F-440

and this 3 page PDF:
http://www.harringtonplastics.com/Ca...n5/5_43-45.pdf


Either way, at $6.50 (+$7.50 s&h), I think I'm off to a good start.

Ah! I found a good reference: the original Blue-White website :rolleyes:

The dimensions

The specs

The manual

(still nothing about pressure drop, and installation details, but I will certainly contact tech support, thanks Bill!)

I posted in the rad thread, but here again.

Blue-White shows a max pressure drop of 2psi for your flow meter Ben. Found it by going through the differant steps as if I were ordering one. You'll come to a data page.

Does not say at what flow rate the 2psi head loss will happen at. Hhhmmmmmmmmmm.

pH or BillA,

As you have and have used one of these, why are they so restrictive & just how restrictive are they?

On a small pump many use I can understand 2psi being pretty notable. But I thought both of you have larger pumps, wrong again?

Well, seems reasonable to me that the max pressure drop will occur at the maximum rated flow (I'd assume that the meter is only calibrated to read to a certain value). Given that it's a "variable area" flow meter, I would assume it's some sort of a constriction (i.e. a Venturi Meter) that uses two pressure readings and the energy equation to solve for flow.

no, the flow rises vertically and 'supports' a slug
5 % ?
that is a sad joke
the slug bobbles around like Janet Reno's hand

and look at the divisons
do I see a tick at each 0.5 gal ?
if so,
that is what can BE READ, interpolations are just to amuse

my old rad data was run with a spring loaded "variable area" flow meter with a magnetic sensor giving 0 - 5 VDC output
- I worked my butt off 'calibrating' it, then later had to revise all the data

I still have a couple of them, $20 ea + shipping

N.B. a magnetic flowmeter at $300 is a MUCH better deal

EDIT: gd qwerty keyboard

It's clearly a rotameter.

Ben, you do realize this must be mounted perfectly vertical? And you're sure the rotameter is calibrated for water?

Alchemy

Yes, I understand the requirement. I'm still waiting for a reply from tech support on the leading and trailing straight pipe length.

2 psi is correct, but I would suspect that that could be above 5 gpm.

2PSI eh? The conversion is (I think) 0.433 PSI per ftH2O so

~4.6 ft H2O pressure drop. What's your pump rated at again? Most of the ones I use in my system's cooling loop can't push the little bell up far above 1.2 GPM...

Yep, 2.0 psi is 55.36" of water, or 4.6 feet. ( www.convert-me.com )

My pump can do max 14.6 feet of head. At 2 psi, it would flow 440 gph, or 7.3 gpm (assuming that there are no other restrictions).

If I can get a couple of pressure gauges, or slap together a manometer, I should easily be able to take some flow measurements of a heatercore.

Hummmm ...manometer...

Work any of these work with little loss?

LOL! the pressure drop chart is there, but no units are specified!

Assuming it's in psi, you'd want to stick with the 1/2 NPT connections.

The turbine wheels have a huge drop.

Yes, I would also assume PSI also :)

For the 1/2" low flow units, the pressure drop for 3 GPM (180GPH) rate is very low (ie almost zero)

Most of us are lucky to get more that 90 GPH (1.5GPM) flow thru our systems.

But I see now that they only go down to 1.5GPM. Oh well, you guys with higher flow rates might want to look at this

There's one that'll take measurements between 0.5 and 5 gpm.

Either way, pHaestus is right, I can't use my flow meter permanently in a loop, at least not until I get rid of the core, for the #rotor chiller, and even then...

EBay alert setup...

It's no good.

The flow range from 0.5 to 5 gpm is only for the 1/4" port, which drops 3 psi at 3 gpm. The units with the 1/2" ports start measuring flow at 4gpm.

Oh well.

Which takes us back to the idea of just using a differential pressure transmitter on inlet and outlet of radiator and choosing a rad that BillA had tested. You measure deltaP and then can calculate Q. Simple enough and no added restriction.

I have a GPI paddle-wheel type for my test system, but I don't see the need for flowmeters in cooling loops I am actually using. The deltaP measurement I could go for, however :)

My feelings exactly

Or simply, I could build a manometer, and use the flowmeter to measure individual components. Whoever said that all I want to measure is the dP through a heatercore?

But I still need a cheap build guide for a manometer. Google time. The pressure gauges are starting to look better.

pHaestus,

So if I wanted to get a rough estimate of a whole systems flow, I would need a pressure gauge near the pumps outlet and another near the intake. Then the differance between the two gauges in psi can be converted to head loss, correct?

Thank you,

BE

If you know the pump's curve, yes, with a tiny bit of error, but "good enough".

Been doing some more looking around at Blue-White. The digital flow meter data sheet shows 0 pressure drop. But just the fact of adding in a T fixture has a head loss, so what is up with that?

Also looked at more flow meter data. Of the 4 I checked all have a max. head loss of 2 psi. Accuracy levels do change, ones I looked at were from 2% to 5%.

Nice Digital meter. Zero head indeed: it's probably a paddle type (not paddlewheel) meter.

Also costs <$400.00

You must consider the application of the equipment FIRST.

Look for spec sheets and prices and such when you know what is required to answer a question. Otherwise you either get sold something much more expensive than needed, or you buy junk that doesn't work.

This is about the sum of the lessons I can provide; still sorting out the good stuff from the junk at my house :)