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George Shirley
 
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Default Health Pressure cooker/canner

James Cooper wrote:
> Meg > wrote in message >. ..
>
>>On 29 Feb 2004 07:31:42 GMT, (BCHUKB) wrote:
>>
>>
>>>Your County Home Economist can test the guage and tell you how to use it.

>>
>>
>>Thanks for the suggestion. I need to find a convex 2" glass gauge
>>cover before I do that. I'm concerned if I put the cover on after it's
>>tested, I may change the reading on the gauge. I'd rather take it in
>>to test when it's in final condition.
>>
>>So far I haven't found any 2" convex glass dial glass, I'll look in
>>the flea markets.

>
>
> The glass is basically just a dust cover. If the guage is working
> properly, removing or reinstalling the glass should have no effect on
> the reading. It's more important to not let water flow into the guage
> when you wash the underside of the lid. Do not unscrew the guage from
> the lid unless absolutely neccessary. This is because the guage pipe
> is stainless steel and the lid is aluminum. It's so easy to
> cross-thread this putting it back on and the stainless steel cuts
> through the soft aluminum threads like butter = start looking for a
> new canner. Perhaps someone knows why these guages even need to be
> calibrated as they have nothing to do with regulating pressure and
> seem to only be good as a warning in case the pressure climbs too high
> allowing one to turn off the heat and take cover, preferably in an
> adjacent building, while it cools down. Having the pressure regulator
> calibrated, or both the guage and regulator, would make more sense.


On many canners, specifically the one from Sears that I use, the gauge
is used to determine the pressure that one will process the food at.
Mine has a "jiggler" just as a safety, ie it will jiggle at 17 lbs psig.
There is also a "blow out" port in the middle of the lid that is rubber
with a stainless middle port that moves. When the stainless middle part
comes upright the canner has positive steam pressure. Air is vented
through the port where the weighted jiggler sits and when a steam flow
is established for a few minutes one puts the jiggler on the port. From
this point on you are regulating heat by increasing or decreasing the
burner until you reach the processing point, in most cases 11 psig. That
pressure is then held by manipulating the heat control to stay at the 11
psig mark. As a consequence and to ensure an accurate gauge it should be
calibrated and reset at least annually and more often if it is in heavy
use.

Many county extension offices can arrange for this calibration or one
can find a gauge repair shop and pay them to do this job. Such shops are
generally in areas where hydrocarbon processing is the main heavy industry.

You are correct about the gauge glass though. While not absolutely
necessary it is used to a) keep the gauge face clean and readable; b)
keep the gauge arrow (pointer) from being manually manipulated or
damaged; c) prevents material from getting into the gauge and gumming up
the works.

There are many websites where one can buy new gauges, typically about
US$35.00 and where you can buy a replacement glass and/or face cover.

George