I just did this to my Magic Seal 16 qt model. This was a Wards model like the Sears Maid of Honor series, but they were all made by presto. I bought mine from pressure cooker outlet listed above. The part number of the outlet fitting is 1058. That replaces your older version and it screws in to the threaded hole in the lid. Easy does it as to much force will strip Aluminium threads. I used Teflon tape on mine, just like plumbing. I also bought the 3 pc weight set. I also found the outlet on ebay $9 shipped. My gripe with the PC outlet $9 shipping which made the total $30 for the outlet and weights. I still love the older machined PC's and these upgrades make them run like a new one. Hope this helps. Larry

Ok, I had to chime in as I repair autoclaves for a living. With the RIGHT autoclave, sterility, safety, and flavor can be maximized. I have two Pelton Crane OCRs (10in diameter chamber,) one Midmark M9 (9in diameter chamber,) and one Tuttnauer 2540m (10in diameter chamber.) Of all the units I have used, the older Pelton Crane units seem to be the most viable for home canning, as I personally use them for this task. This autoclave uses a bellows to allow air in the chamber to be displaced by steam as the chamber heats up. It has a safety valve which will open in an over-pressure condition, usually at either 35 or 40 PSI. The analog temperature control is fully adjustable, regulated by a chamber steam temp sensor and TRIAC circuit. If you are worried about gauge accuracy, remember that there is a direct correlation between steam pressure and temperature. (See attached picture for a chart listing correlation points between temperature and pressure.) As long as the temp and pressure gauges correlate, it should be accurate. If you have doubts, a max register lag thermometer can be used to confirm the max temperature. If the max temp displayed on the thermometer matches what was shown on the gauge, and the temp and pressure gauges correlate, there is nothing to worry about. (If you are not running back to back cycles. More on this later.) When I am canning (or sterilizing liquid growth media or IV fluids) in it, I just run it at a lower temp for liquids, and only partially vent it at the end of the cycle to allow the water at the bottom of the chamber to exit. After the venting sound switches from water to steam bubbling through the condenser tube in the water reservoir, I allow the pressure to get down to about 5 PSI before closing the valve and allowing the unit to cool down naturally before opening the door. This will allow the pressure in the jars to come down some, and prevent exploding. This is mainly an issue if you are running cycles above 252F. For reference, pressure canning is usually done at 240F / 10.5 PSI, which is EASILY achievable in an autoclave. Lastly, when using an autoclave, you MUST remember to allow the unit to cool down enough for the bellows for it to open the chamber air vent valve. Failure to do this will cause air in the chamber to not be displaced by steam, leaving a space in the autoclave that DID NOT get up to temperature. -Adam Nash

As others have said you can use the pressure canner if it allows 2 inches of boiling water above the jars. Be very careful, however. Two years ago I was using this method and had locked down the lid leaving the vent open as JodieMo suggested earlier. A small amount of pressure had built up and when I removed the lid, the superheated water exploded up out of the canner and burned me quite badly. I still have the scars to prove it. This was a very old canner (it has since been retired) and did not contain the pressure lock that modern Presto models have. However, I will never again lock a pressure cooker lid down for boiling water processing. Either remove the seal or search for a lid that fits the pot.

Dare I say something in defense about a steam canner? I have used one for many years now and it uses about the same amount of water a pressure canner uses. It has proven it worth here by giving me many canned items that are not overcooked. I especially like it for jellies and pickles. Neither are difficult to can, or process. Because I add extra acid to both, safety issues are not a big concern. I had done many temperature tests on these, and have found that the recovery temps are quite fast, when it comes to the canning water coming to a boil again. As everyone knows, heat rises, cold drops. With room temp, water filled jars inside, and the canner water previously boiling, it can take at least 10-15 minutes for the canner to reach boiling again, even though the jars are not even touching the water. Also, the measurements I did were done with thermocouples and a device that is able to chart out 6 locations within an area. These temperature measuring devices are very accurate and when I had jars filled with water only, and measured the internal temps, they came up faster in heat than a boiling water bath. I am not saying a pressure canner is in the same class, as it is not. Pressure canners are used for low acid foods and offer higher processing temps above 212 degrees of boiling water. This is the reason for the high pressure used in a PC. The steam canner has a slight pressure when boiling, as it jets out a strong steam from just two tiny holes down near the water level. This indicates to me that the jars inside, are in fact exposed to something that is at least 212 and is under slight pressure. I measured an internal temp of 212 degrees inside a water filled canning jar after 10 minutes. That jar was filled with boiling water prior to the test however. I would never consider using this canner for any low acid products. For pickles, I prefer full 5% strength vinegar too. The jellies get an added acid blend of malic, tarteric, and citric acid.