Pressure guages

[tmuir]

Another newbie question.

Can someone explain the differences to me for pressure gauges used for air / steam or water, or if there is any differences.

I would like to get a pressure gauge to do basic hydrolic tests on small simple pot boilers I plan to make.

These would all be 200ml or less in size with operating pressures below 15 or 20 PSI.

Just for my own peace of mind I would like to test them but I'm unsure what gauge I would need to get.
I've seen gauges sold to use for hydrolic testing but with huge price tags. I really wouldn't be testing over 60PSI so see no need to get one this expensive, and I wouldn't care if it was off by 5 or 10%.

Thanks

 

[Majorstrain]

I'm another newbie interested in the answer also. :noidea:
Phil

 

[RobWilson]

Hi tmuir, There is no real difference between an air gauge or steam gauge,true steam gauges are built to a higher standard,there is a difference with a hydraulic gauge in that they are oil filled to acted as a damper.
So any small air gauge will do fine at the pressure you will be working at
Rob

 

[PTsideshow]

The biggest problem could some of the cheaper import air gauges might not be up to the heat and shock of steam impacting the internals. Also make sure you have a pig tail or siphon to protect what ever type of gauges from thermal shock.
Because even steam gauges aren't made for steam/heat on the internals

The biggest thing is if you have a known correct working gauge you can test the new one against and then test it on the steam you will have a good idea if it will work.

An indication of one that doesn't work correctly is when doesn't go back down to the 0zero peg after the pressure is gone. some of the cheap gauges will appear to work but, are damaged when steam is applied
;D

 

[tmuir]

For actual steaming I have a spare Stuart gauge to fit. I just don't want to use a 1/2 inch guage for hydrolic testing of the boiler, want something easier to see for that.
Will have a dig around on ebay for a cheap pressure gauge then.

 

[shred]

I used a cheap surplus gauge when building my little loco, and it worked well enough for that. I got a selection of them from www.surpluscenter.com a while back for a few dollars each so I don't feel too bad if one gets destroyed in testing or use occasionally. I did bend the pipe 360' as a pigtail for steam use, although when I did the hydro it was just straight pipe.

http://www.homemodelenginemachinist.com/index.php?topic=2049.msg34194#msg34194

 

[Majorstrain]

Flea Bay has some Fuel pressure gauges in the range of 0- 21psi and 0- 30 psi, some oil filled and some not. All are under $50 AU.
Too low for hydro testing but has anyone used them? and how did they go, on air or steam?

Phil

 

[tmuir]

Would this one be ok for Hydro testing up to 60PSI.
http://cgi.ebay.com.au/New-100-PSI-7-Bar-Rain-Water-Pump-Tank-Pressure-Gauge_W0QQitemZ280337779004QQcmdZViewItemQQptZLH_DefaultDomain_15?hash=item280337779004&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A1|39%3A1|240%3A1318|301%3A0|293%3A1|294%3A50

 

[Kermit]

going digital would cost about $200 or so.

$100 for the transducer of 'good' quality. and the other hundred for the required display/converter.


One place to have a look-see
http://www.sensortechnics.com/index...0&aps=0&blub=767d33b3f7b4b95e9d35420c978c9c61

Omega would be an equivalent American manufacture/dealer.

Just showing some options. We use this type of setup for 99% of the pressure gauge-ing @ work. Mostly with 4-20ma transducers. MiniDin size displays can be found for under a hundred as well.

 

[firebird]

Hi

If you look at my small boiler topic and the current small steam engine project you will see the hydrauilic test I did and the guage I used. I bought it for £10.00 at a steam fair.

Cheers

Rich

 

[Stan]

With bourdon tube gauges, it is preferred to have the working pressure at the center of the gauge scale. To measure 60 PSI you need a 100 PSI gauge so that you don't damage the gauge with overpressure. A 100 PSI gauge will not be reliable at 10 PSI.

You would be best served with two gauges, one a 30 PSI ad one a 100 PSI. When measuring either high pressure or high temperature it is best to have a gauge with a safety back that will fail in case of a bourdon tube failure. You don't want hot high pressure blowing out the glass cover in your direction.

 

[bob ward]

The beer reticulation industry uses relatively low pressure CO2, 10 psi or so, to push the beer around, the gauges they use typically max at 40 to 50psi.

Andale is one company in the business in Australia

I imagine most pubs will have an old CO2 gauge or two sitting in the store room, you may have to visit a few pubs in your search

 

[bearcar1]

Aye lad, now THAT is a brilliant idea. After a few Old speckled Hens and a few attempts at the servers telly number and provided you don't get thrown out first, you could politely inquire of the tender if he has an old gauge he would be willing to part with. Then, with it carefully stashed in your coat pocket stumble your way back to the cottage and fall asleep, smug in the knowledge that you not only found the piece you needed but also got a new number to call. Rof}

BC1