Replacement & Storage of 123 filler cap washers & pips?

Discussion in 'Fettling Forum' started by Pinnah, May 19, 2020 at 9:19 PM.

  1. Pinnah

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    Short and direct version:
    1) What is the best way to store 123 filler caps (or washers) so that they don't get hard with age?

    2) Is it best to replace filler cap washers at a regular interval even there are no visible problems and if so, what is a good interval?

    3) Do pips need to be replaced regularly and if so, should this be done by time interval or is there a mechanical test that can be performed (without the need of a special fitting and compressor)?


    Long and rambling version:
    I have a 123R I've been using regularly since '85. The first year I got it, I over heated it and experienced the 4' flame thrower that Colin Fletcher described. Not knowing any better, I just replaced the o-ring (knew nothing about pips) and used that gap for another 10 years.

    Eventually, I got a new cap and have been using that cap for decades. Stove gets used 12 to 4 trips a year depending on lots of factors and has always been stored with fuel in it and cap snug. Never a problem.

    Some years ago the stove lost its power so to speak and on a recommendation from A&H, I replaced the wick which went smoothly and revived the stove. At the same time, I purchased 2 new filler caps to hold in reserve.

    The past 5+ years I've been using the Svea only 1 or 2 times a year for car camping; relying on a Trangia for 3 season backpacking. For some reason, I started storing the stove dry and I'm not sure if that is good or bad.

    This past week, I took the Svea out on a birding trip to make tea for my wife and the very old cap started leaking slightly out of the pip.

    So, I swapped out the filler cap for one of my reserve caps that has been sitting in my gear box for 5-10 years and the stove wouldn't pressurize. Some testing with a lighter showed leakage at the bottom of the filler cap. (Over) Tightening the cap with a 10mm wrench confirmed the diagnosis and the stove fired right up. Same thing happens with the 2nd spare cap (same vintage).

    Obviously, I don't trust any of my current caps. Over tightening a cap isn't the fix for a bad o-ring and I'm in the process of ordering new o-ring/pips from The Fettle Box.

    But this raises three questions for me.

    1) How can I store filler caps in a manner so they don't go bad as my back ups have? Related, is it better to store a user Svea wet or dry?

    2) Should I just get new o-rings regularly and if so, how often?

    3) Do I need to replace pips that aren't leaking? I assume that too hard means it won't release properly? I'm pretty intimidated by pip replacement so there's that.

    Thanks for any guidance you have.

    Here's a shot of the stove in use 2 years ago. Dinner by a backcountry river... IMG_1820.JPG
     
  2. Tony Press

    Tony Press Australia Subscriber

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    @Pinnah said:

    1) What is the best way to store 123 filler caps (or washers) so that they don't get hard with age?

    A: If you use quality Viton washers and pips, they should last for years (5 to 10) unless they get distorted in use. I store mine in small ziplock bags, in a moisture free environment.

    2) Is it best to replace filler cap washers at a regular interval even there are no visible problems and if so, what is a good interval?

    A: See above. Best practice is to test the stove before taking it into the field, and carry spare washers if you’re out in the wilds for some time.

    3) Do pips need to be replaced regularly and if so, should this be done by time interval or is there a mechanical test that can be performed (without the need of a special fitting and compressor)?

    A: Ditto. Testing before going into the field is good practice.

    ...

    But this raises three questions for me.

    1) Related, is it better to store a user Svea wet or dry?
    A: If good quality Viton is being used it should be ok to store “wet” if it’s used regularly.

    2) Should I just get new o-rings regularly and if so, how often?

    A: Which part is the O-ring. Is that on a cap for a mini pump? Don’t replace flat washers with O-rings except emergency or short-term use.

    3) Do I need to replace pips that aren't leaking? I assume that too hard means it won't release properly? I'm pretty intimidated by pip replacement so there's that.

    A: See answers above. The pip should last quite a while, and testing before use will let you know if there’s a problem.

    Cheers

    Tony
     
  3. Pinnah

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    How does one test a pip with a compressor type set up?

    Sorry about the confusion about o-ring vs washer. I meant washer.

    thanks for the help!
     
  4. Ed Winskill

    Ed Winskill United States Subscriber

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    I just put them in the basement and take them out again in hiking season. No special precautions. I'll let my offspring worry about the next seal and pip changes.
     
  5. snwcmpr

    snwcmpr Subscriber

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    I do not store them specially.
    I replace the pip if I replace the gasket.

    An old cap will most likely have an old seal. Even a New Old Stock cap might have an unusable hard gasket and pip.
     
  6. Tony Press

    Tony Press Australia Subscriber

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    I test the pip by lighting the stove and boiling some water for tea and see if it leaks.

    Tony
     
  7. Pinnah

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    I admit to not understanding the internals of the SRV in the slightest. Searches on how to test pips function leave me wondering if they can be safely replaced.

    Do pips ever fail by not opening?

    While annoying, a leaky pip isn't catastrophic. Especially in the field if you carry a spare cap.

    But I do get scared of a pip failing to open if I overheat the stove. That would be horrible.
     
  8. Ed Winskill

    Ed Winskill United States Subscriber

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    It would be troublesome, but not horrible most likely.
     
  9. Tony Press

    Tony Press Australia Subscriber

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    If the safety release valve is (was) set up correctly, then a pip that goes hard with age won’t jam shut. It will most likely release pressure “prematurely”.

    The “failure” of the SRV would be release of vapour or fuel.

    Tony
     
  10. Radler Switzerland

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    @Pinnah
    You can test all gaskets easily with a wooden toothpick: press the pick against the gasket an see if it's soft. If the gasket is harder than the wood, it's time to replace it.
    Pips in the safety valves can fail it they are sticky. Old oil can become like glue. Check if the valve outlet-hole is clean. With a non-pointed stick you can feel if the pip does move or not through the hole at the inner side.

    Regards Radler
     
  11. Pinnah

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    Super helpful !!!

    Thanks
     
  12. pysen78

    pysen78 Subscriber

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    As for storage:
    I used to have some gaskets in zip lock bags in the same cupboard where i store my fuel. That means butane, coleman fuel, kerosene and, alcohol in more or less air tight containers.
    It turns out all gasket materials have turned brittle i a matter of a few years.
    Spares stored elsewhere are still in good shape.

    Conclusion, don't store your spares with your fuel!