Last updated: August 23, 2026
A canner that has been in the family since the seventies is usually still a good canner. What it is not is a sealed unit. The rubber in it has been through hundreds of heat cycles, the gauge has been knocked around in a cupboard, and the parts that keep it working are consumables that somebody was supposed to replace at some point.
The trouble is finding the right one. Model numbers are stamped somewhere unhelpful, part listings talk about cookers and canners in the same breath even though the parts differ, and the search results are full of aftermarket rings that fit almost. This guide sorts out which parts wear, how to tell when, and how to match a part to your canner without guessing.
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Quick Answer
Which pressure canner parts wear out and how do you match them?
- Find your model number first. It is stamped on the canner body or the underside of the handle, and parts are sold by model, not by size alone.
- The sealing ring and the overpressure plug are rubber and they harden. Replace them as a pair.
- Dial gauges drift. The NCHFP recommends having them tested each year, and a failed test means a new gauge.
- All American canners have no gasket at all. Their metal to metal seal needs cleaning and care instead of parts.
Bottom line: model number first, then the rubber, then the gauge. Buy the parts the canner maker lists for your model.
Find Your Model Number Before You Shop
Every parts mistake starts here. Presto stamps a model number on the canner, and the same brand sells different rings for its pressure cookers than for its canners even though they look similar. Ordering by capacity alone is how people end up with a ring that sits a fraction proud and leaks steam all season.
Look on the body near the handle, on the underside of a handle, or on the base. Write it down and keep it somewhere you will find it next August, because that is when you will need it and the canner will be full of jars.
Cooker Parts Are Not Canner Parts
This trips up a lot of buyers. Presto lists part 09936 as a sealing ring and overpressure plug pack for its smaller pressure cookers, and part 09985 as the canner sealing ring and overpressure plug pack for its 16, 18 and 23 quart canners. The numbers are one digit apart in the search box and completely different parts on the shelf.
The Sealing Ring
The ring sits in the channel around the inside of the lid and is squeezed between lid and body to make the steam tight seal. Heat cycling is what kills it. It goes from supple to firm to glassy hard, and once it stops springing back it cannot fill the gap, which is when steam starts escaping from the rim instead of the vent.
Check it by pinching. A good ring gives and rebounds. Look for flat spots, cracks at the inner edge, tackiness, or a ring that has stretched enough to fall out of the channel when you turn the lid over. Wash it in warm soapy water rather than the dishwasher, and store the lid upside down on the canner rather than clamped on, so the ring is not compressed all winter.
Aftermarket Rings, Honestly
Third party rings for popular canners are everywhere and the quality genuinely varies. Owners report both good service and rings that harden within a season, and the failure mode is a leak rather than anything dramatic. If your canner is your main preserving tool, the maker’s own part is the version that removes the variable.
The Overpressure Plug
The small rubber plug in the lid is a safety device. It is designed to release if the vent pipe blocks and pressure climbs beyond the working range, and like the ring it hardens with age. A plug that has gone stiff may not release when it should, which is precisely the scenario it exists for.
Replace it with the ring. Presto’s canner sealing ring packs include the plug for that reason. Installation is a push fit from the underside of the cover, and the plug is marked so you know which face goes up, so check the orientation in your manual rather than pressing it in either way round.
Gauges, Weights and the Vent Pipe
A dial gauge is a spring instrument and drifts over the years. The NCHFP recommends having dial gauges tested for accuracy annually, and county extension offices commonly do the test. If it reads off by more than the tolerance your extension office gives, or if the needle does not rest at zero cold, buy a replacement gauge rather than mentally adding a correction.
Weight style regulators do not drift, which is their main practical advantage. They can be damaged or lost, though, and a canner without its weight is not usable. Keep the weight in the canner rather than in the drawer of small kitchen things.
The Vent Pipe
Not a part you buy, a part you clean. Hold the lid up to a window and look through the pipe. If you cannot see daylight, clear it with a pipe cleaner or a straightened wire before the next batch. A blocked vent is the condition the overpressure plug exists to handle, and you do not want to find out whether yours still works.
All American Canners Are Different
All American canners use a machined metal to metal seal closed by wing nuts, which the maker describes as an exclusive metal to metal sealing system with no gaskets to replace. There is no ring to buy and nothing rubber to harden in the seal itself, which is the main reason people buy them.
They are not maintenance free. The two machined faces have to be clean and undamaged, the manual specifies a light film of lubricant on the sealing surfaces, and the wing nuts are tightened in opposing pairs so the lid pulls down evenly. They still have a gauge and safety components that need attention. Our comparison of Presto and All American goes through what that difference means in practice.
Parts, Symptoms and Timing
The table pairs each part with the symptom that points to it. The gauge testing recommendation is the NCHFP one; replacement intervals for rubber parts depend on how much you can and how the canner is stored, so treat them as inspection prompts rather than schedules.
| Part | Symptom when it fails | How to check | When to act |
|---|---|---|---|
| Sealing ring | Steam from the rim, slow pressure build | Pinch for suppleness, look for cracks | When it stops springing back |
| Overpressure plug | Hard, discolored or dished plug | Press it, compare with a new one | Replace with the ring |
| Dial gauge | Needle off zero cold, odd readings | Extension office test | NCHFP recommends testing yearly |
| Weight regulator | Lost, chipped or wrong weight fitted | Compare with the manual | Before the season starts |
| Vent pipe | Poor venting, erratic pressure | Look through it at a light | Every season, and after a messy batch |
| Handles | Cracked, loose, scorched | Wobble test when cold | Any crack, they carry a full pot |
Frequently Asked Questions
How often should I replace the sealing ring? There is no fixed interval, because it depends on how many batches the canner runs and how it is stored. Inspect it at the start of every season and replace it when it has hardened, cracked or flattened. A ring that no longer springs back when pinched is finished regardless of age.
Which Presto sealing ring fits a 23 quart canner? Presto lists part 09985 as the pressure canner sealing ring and overpressure plug pack for its 16, 18 and 23 quart canners. Part 09936 is the equivalent pack for smaller pressure cookers, so check the model number on your canner before ordering.
Do All American canners need a gasket? No. All American describes its canners as using a metal to metal sealing system with no gaskets to replace. They do need clean sealing surfaces, the lubrication the manual specifies, and wing nuts tightened evenly in opposing pairs.
Can I get my dial gauge tested locally? Usually yes. Many county extension offices test dial gauges, often free or for a small fee, and the NCHFP recommends having it done each year. Call ahead before canning season, since the testing equipment is in demand in July and August.
Is a hardened ring dangerous or just annoying? Mostly it leaks, and a leaking canner may not reach or hold the pressure your recipe requires, which means low acid food that was not processed as the tested recipe intended. That is why it is a safety issue rather than a nuisance. Replace the ring and reprocess or refrigerate anything you are unsure about.
The Bottom Line
Write your model number down, buy the ring and plug the maker lists for that model rather than the closest looking one, and inspect the rubber before every season instead of during a batch. Get a dial gauge tested each year as the NCHFP recommends, clean the vent pipe, and remember that an All American needs care of its machined faces rather than a gasket. Read next: pressure canner troubleshooting for the free checks, and pressure canners if the old one is past saving.