National Canner Questions

[jessireb]

I have an older National Canner #7 and just bought a new seal for it. Included in the with the seal was an automatic air vent. The instruction say to replace the air vent, but I can't figure out where it goes. Anyone who can help me I would appreciate it.

[mcnerd]

I have no idea what an old NC #7 looks like, but you should have one center vent (on the lid) that either has a dial gauge or a stem for a weight gauge. There should be at least one and possible two other vents, with either another vent to hold a weight (coincides with a dial gauge), a rubber stopper, and/or a popup vent. I would assume your replacement piece would look like what you are replacing or your canner may be older than represented.

[Michael in FtW]

I was unable to find pictures of an old Model 7 but I'm going to venture a guess that it might look similar to the old Model 12 below. To the right of the guage is the vent tube where you probably put the pressure weight, and the stub to the left is the pressure relief plug. I can only guess that the new automatic air vent/pressure relief would replace this plug.

I would suggest you contact someone who may actually be able to give you the correct answer. The Cooking and Canning folks (check the site for email and toll-free phone number) - since they sell the parts for the old National Model 7 they should be able to tell you how to replace the old parts with the new ones.

[jessireb]

In the center of the lid between the gauge and the petcock (screw vent) there is a metal type disc that is soldered underneath. I assume this is a safety feature that will blow if too much pressure builds up. Those three are the only things on top. The last picture shows the top better.
Nothing that looks like the vent that came with the gasket/seal.

[Michael in FtW]

Originally Posted by jessireb

In the center of the lid between the gauge and the petcock (screw vent) there is a metal type disc that is soldered underneath. I assume this is a safety feature that will blow if too much pressure builds up. Those three are the only things on top. The last picture shows the top better.

Nothing that looks like the vent that came with the gasket/seal.

The over-pressure valve that you got with your sealing ring (as a kit) is a retrofit replacement part that would go into that hole between the petcock and pressure guage if you had blown the original over-pressure plug, or if you wanted to upgrade to the new style valve. It probably looks like this:



So, yes - you are right ... your canner has nothing that looks like it. You could have bought just the sealing ring alone - without the plug.

Is there a reason to retrofit it before the original valve fails? I don't know. I still suggest you contact someone who works with these things for a living and has the answers. I gave you that contact info in my previous post.

[jessireb]

thanks so much for your help. I will be emailing them or calling to see if I need to replace it.

[margoc]

I got an old national 7 and refurbished it with all american parts, like the vent tube, jiggler, and new guage.



Since then I added new bakelite handles. It works awesome! I have an all american 921 and tried the parts out to make sure they fit first, then got parts to fit. The 921 has greater pint capacity but the national 7 works great too, it's easy to close without all the nuts, not that it's that big a deal.

It's nice to have 2 pressure canners, plus if I have to I can use the parts off one for the other.


The nice thing about the new presta pressure valve pictured is that it has a metal pin in the center so when it depressurizes it won't make a vaccume. I keep an eye on mine but it's still nice to know. Supposably it's an automatic venting valve, according to the manual, the metal thing stays open till it's vented supposably.