Any air experts? air ammeter needed

[jason udallParticipant @jasonudall57142]

Can only offer what I would have done.
.
If a leak can be “heard”.. or otherwise detected..
Isolate chunks till leak goes away.

Thusly your need for a flow meter. ..

Now the u/s detector might be steep but really is this so expensive in comparison to three expensive guys waiting round….
What I would have done was isolate a bay at a time and Isolate the culprit.

Isolate and watch pressure drop…think RC discharge. ..the rate of pressure drop will indicate consumption
…either way you are needing to isolate and monitor. .

[Ben SpicerParticipant @benspicer30986]

Hi.

At work we used an ultrasonic leak detector. Our compressor room if extremely noisy with 7 large oil free 2 stage compressors screaming away. It comes with noise cancelling ear defenders which connect to the detector.

The detector itself has some sort of crystal in the end which becomes "excited" when in contact with an air leak. This the actually gives you a totally individual sound of each leak. You can even get a rough idea of the size of the leak, it sounds that good. It will also guide you to the leak if your in the rough area, as the crystal becomes more excited you will hear the leak becoming more intense.

I'm NOT connected to this manufacture in anyway, its just a useful piece of kit we use. I'd imagine that you would have to take all the panels off anyway to attach a "meter" of some sort.

We've found loads of leaks all over our site, ones that you wouldn't hear or feel before. Hope this helps.

Ben.

[mark mcParticipant @markmc72333]

What about a bit of uv dye put into the airline, same method as aircon leaks in cars? Hell of a lot cheaper than fancy detectors, 20 quid would buy the dye and torch.

[Trev67Participant @trev67]

Hi Ian

Sounds like you need the equivalent of a leak down tester, used on engines to test for cylinder leakage.

Basically it is an orifice ( in the case of cars they use 40 thou) with a pressure gauge either side.

If you plumb the tester in at A in your diagram, and there is no air leak or flow both gauges will stabilize to the same value, the more flow the greater the difference in the gauge readings. So if you can either turn off all the valves and open one at a time to find the greatest pressure drop, or have them all open and shut off one at a time to find which one makes the biggest difference.

If you have no idea what size restrictor orifice to use between the two pressure gauges, you can put a shut off valve in, and use a bit of trial and error to get a meaningful reading.

Because it is only a comparison tool there is no need for absolute accuracy or calibrated gauges, you are just comparing the flow through the machine against the flow through the restrictor, and if it is significant it will show up as a pressure drop.

Hope this helps

Trevor

[Ian ParkinParticipant @ianparkin39383]

I have sorted the problem now with the flow meter bought off ebay

I tried it on my compressor in my workshop connected up at 150psi for about an hour ( gauge rated to 100psi)

It seems fine its solid acrylic 1" x 1.5" with 2 tapped connections,I'm not sure what would happen if it failed coud it explode with shards of perspex eveywhere?

Anyway on connecting to the machines supply it was a simple matter to isolate each unit until one was apparent it was consuming lots of air at rest so panels off and the leak was obvious.so good result with lots of time saved

after repairing the leak the flow meters ball was just off its rest at the bottom rising fully to the top if I actuated one valve so its nice and sensitive ( the scale is marked at 0-20 SCFH )

Ian

Ben how much roughly is that skf gadget?

[Ben SpicerParticipant @benspicer30986]

Hi Ian,

The SKF detector is about £900 +VAT from what I can see online. There might be a newer one out now or something but that's the price that's online. I wouldn't want to drop it .

Ben.

[Les Jones 1Participant @lesjones1]

Hi Ian,
How about using a water flow meter. Although they are designed for water I cannot see why they should not work with compressed air. (The calibration would probably be wrong but I suspect you only need a comparative reading.) They work by the flow rotating an impeller. If my conversion is correct then 4 cu ft per minute would be 113 litres per minute so one like this would probably be OK

**LINK**

They are rated at 2 megapascals which is 290 PSI

The output is a frequency so you should be able to find a digital multimeter that has a frequency range to display the output. It would also have the advantage that you could have along lead to the display so you could see the result of opening and closing valves to isolate sections of the machine.

Les.

[Ian ParkinParticipant @ianparkin39383]

Les

that looks great i'l order one of those to play with

Ian

[Les Jones 1Participant @lesjones1]

Hi Ian,
Overnight it occurred to me that the 4 cu ft per minute may be the free air delivery rating of the compressor. (Rather than the volume of air per minute actually at 150 PSI) If this is the case then the actual volume of air at 150 PSI would be about a tenth of this. (0.4 cu ft per minute or 11.3 litres per minute.) If this is so then a smaller flow meter would be more suitable. If you search on ebay for "flow meter" you will find many flow meters that amy be suitable. You can also find "ultrasonic leak detectors" on ebay.

Les.

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