# pressure canner gauge



## freelove (Jun 17, 2005)

I have inherited an old National pressure canner and I would like to learn to use it. I know that the dial gauges need to be calibrated. I have called cooperative extension and they do not do calibration and it seems no one locally does it. 

DH is a multi-talented engineer, machinist, and has other abilities too numerous to list. He has a machine shop and most every tool known to man, I am sure he could do it. My question is, how is a pressure canner dial gauge calibrated? Does anyone here do it? 

Thanks!


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## PlicketyCat (Jul 14, 2010)

First, you should determine what model you have, then contact the manufacturer to see if the gauge can be adjusted, if they will calibrate it for you (and the cost), or if they sell a replacement. In most cases, it's safest to simply replace old gauges of unknown condition.

If the manufacturer won't calibrate it and you can't find a replacement, you can calibrate pressure gauges using another accurate pressure gauge and something that creates stable and adjustable pressures (like a compressor). Measure the pressure of the same thing with each gauge, and then adjust unknown gauge if necessary. If there isn't a way to adjust the gauge, just mark the gauge with "reads X psi low/high".

I've only adjusted one pressure gauge (not my canner) by hooking it up to my air compressor. In that case, the end fit the hose quick-connector perfectly; but you might need an adapter for something with a non-standard end.

Personally, if I couldn't get a proper calibration or a replacement gauge, I wouldn't trust it for safe operation or safe food preservation... just use the old canner as a BWB or heavy stockpot.


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## Guest (Jun 27, 2012)

does it have a weight?


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## Ruby (May 10, 2002)

If it has a weight you can use that instead of the gage.


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## freelove (Jun 17, 2005)

Thank you all for your help. I have found a website that still sells gauges for old Nationals and think I will order a new one.

Thanks, again!


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## PaulNKS (Jan 11, 2009)

Before assuming you need a new gauge, have your local extension service check the gauge. Many of them do that for free or a very minimal cost.

My old canner is a National. Check your gasket as well. If you are going to order a new gauge, order a new gasket so that you have a spare on hand.


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## freelove (Jun 17, 2005)

Thanks, Paul. I checked with cooperative extension and they do not calibrate canners. Good advice on ordering an extra gasket.

Thanks again.


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## margoC (Jul 26, 2007)

I have an old national #7 that I refurbished. I ordered an all american vent tube and jiggler. I simply purchased a new guage and a couple of gaskets. The thing works great!

I try to find the thread I started on it when I get home.

I personally wouldn't mess with a canner that did not have both a jiggler and guage, it's just too much trouble. I like having backup ways to monitor my canner.


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## freelove (Jun 17, 2005)

Thanks, Margo. 
I will be very interested to see the thread you started.


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## PaulNKS (Jan 11, 2009)

freelove said:


> Thanks, Paul. I checked with cooperative extension and they do not calibrate canners. Good advice on ordering an extra gasket.
> 
> Thanks again.


I didn't say to have them "calibrate" it. None of the extension offices will do that. All they do is test it and tell you how far off it may or may not be. For example, if they test it and it reads 12 pounds when it should read 10, then you know that when you are using the canner, just bring the pressure two pounds higher than the canning instructions call for.

If your county doesn't test them, call another county, if it isn't too far from you. well.. by the time you drive to another county, you may have been able to pay for a new gauge with the gas money. lol


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## po boy (Jul 12, 2010)

You most likely have a national # 7....
Margo mentioned her conversion and way back when she posted her info I PM'd her about her conversion and did mine. It works great!
Thanks margo.

Here is the info she sent me:
*National #7 Conversion* 
Here is the link to the jiggler
All American Pressure Regulator Weight 68

Here is one to the vent tube
All American Vent Pipe 69


I just replaced both of them with the all american parts in the links. I used a little teflon tape to put the vent tube in. I was concerned that the jiggler would not work properly because the lid has a slight curve to it but it doesn't seem to make a differance.

Here is a link to old national #7 parts. I replaced the gasket and the over pressure plug while I was at it. 

Notice there is a pressure canner regulator kit in that last link. I am not familer with it, that's not the one I got. Mine are both the same now so I can use either one as a back up just in case. 

The refurbished old national is lighter and easier to use when I don't have as much. It's nice having both of them, I have crunk them both up a time or too.


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## freelove (Jun 17, 2005)

Ok, Paul, wrong terminology. My error. My county extension office doesn't test them either. I am checking around and might have found one that will test it, but it is not very close to me and transportation is a problem. I might be able to mail it.

Po Boy, thanks for the info and links. Yes, it is an old #7. I really want to get this canner up and running for a couple reasons. First, I can't afford a new one. I would not spend money on a cheap one and a really good one is way, way out of my price range. Second, this canner has been in my family for a couple of generations and it is nostalgic for me. 

I really appreciate everyone's input and wisdom, thank you.


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