Can you trust the NRV of the Optimus Hiker+ when using gasoline?

Discussion in 'Stove Forum' started by Skopar, Dec 6, 2019.

  1. Skopar

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    Hello. Despite the fact that I joined the forum a few years ago, and that I have been reading you for even longer, I have never posted anything until now. I was learning a lot just by reading, and all my questions were always answered with a bit of search.

    This time I have, what I believe to be, a question non-dealt with yet. Thanks to readning you, I have understood the secuirity of the Coleman's Non-Return-Valves in gasoline stoves, the fact that the rest of the NRV always fail sooner or later (I have a kerosene Optimus 111 and a German Army's Geniol that failed), that this is not an issue for self-pressure gasoline stoves because thet have no pumps, and that the failure of NRV is only dangerous if you are dealing with gasoline. This last statement is because kerosene does not behave like gasoline, should the NRV fail.

    Now my question is about the lastest and discontinued version of the Optimus Hiker+, which is suposed to use white gasoline, car unleaded gasoline, kerosene and JET-A/1. How safe if the Optimus Hiker+ if I use it with white gasoline? Am I risking a NRV failure like I got with my Optimus 111 and then, because of the gasoline, getting a ball fire? Can I trust the Optimus Hiker+ when used with gasoline, if not as much, at least close to what I would trust a Coleman stove?
     
  2. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi @Skopar Welcome to posting on CCS.

    It is generally accepted that if you only have a single barrier between a pressurised inflammable liquid and an ignition source, you need to be very careful to ensure that the barrier is of good quality and well maintained.

    As far as I know the Optimus Hiker+ design, like its ancestor Optimus 111- type stoves, relies on the NRV as a single barrier between fuel and potential ignition.

    The Coleman approach of a screw-down barrier, in addition to the NRV seal, is intrinsically safer.

    Best Regards,
    Kerophile.
     
  3. Tron

    Tron Subscriber

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    With all respect, I believe the most important safety feature of the Coleman system is not the way their NRVs are made, but that the NRV is inserted in a tube that rises up above fuel level, to the top of the tank. So, in event of a failure, the NRV vents air/gas, not fuel. All Coleman GPAs are made that way, Lanterns, Suitcase stoves, Hiking stoves etc.

    Optimus, actualy Katadyn, changed their pumps for remote tank stoves to copy this concept sometime around 2010, their pumps now have the NRV sticking out 90 degree from the pump body, opposite of the fuel pick up tube. In normal operation, if the NRV fails it will vent the air at the top of the tank, not fuel. I do not know if they have extended this feature to the Hiker+, although I imagine it would be easy enough to do. Someone need to ask Katadyn, or cut open a Hiker+ tank.

    Personally I would never thrust an Optimus 111 style pump/NRV system with volatile fuels. I you do not really use it, but just fire it occasionally or operate it in the yard and take necessary precautions, it will be fine of course. But I need to trust my stoves to be safe to use in a tent or Lavvu, and safe for my kids to operate, so I stay away from anything that might fireball unexpectedly.

    Tron
     
  4. Marc

    Marc Subscriber

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    I think Coleman's multi tiered approach is best. Coleman's metal ball check valve NRV is more reliable and doesn't degrade over time like a leather/rubber pip will, plus the redundant manually locking valve, plus only venting the air above the fuel and not the fuel itself in case of failure, each step adds an additional level of safety. Coleman appliances, and appliances without an NRV, are the only white gas appliances I trust.

    It's for this reason that I consider the modern MSR and Optimus stoves to be kerosene stoves, regardless of how much they're touted as multi-fuel. The ability to burn gasoline is a bonus, a way to get someone out of trouble or out of a jam by being able to use gasoline if that's all that's available, but gasoline should not be considered the primary fuel for these stoves. It's worth going to some trouble to make sure kerosene is kept on hand.

    Putting it lightly, my views are not shared by everyone here.
     
  5. snwcmpr

    snwcmpr Subscriber

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    I have voiced my opinion. I do not use them. Others have used them safely for many years. I think it only takes a few seconds for the problem to surface. It is unlikely that a person will remove the NRV every time to check it before ise.

    Coming around this forum has made me like kerosene much more.
     
  6. Retro Camper

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    I got rid of my petrol/gasoline stoves a few years ago - kerosene only for me these days as a pressurised fuel. Incidentally, I presume alcohol in a 111T has to be treated with the same respect as petrol/gasoline.
     
  7. snwcmpr

    snwcmpr Subscriber

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    Alcohol flame would most likely be invisible.
     
  8. Doc Mark

    Doc Mark Subscriber

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    Greetings, @Skopar ,

    I guess I'm one of the oddballs, here, in that I definitely trust my Optimus, MSR, and some other similar stoves, when using Coleman Fuel. I've used it for many years, and never had a single problem. I guess I should say, I've only had ONE problem, and that was when one of MSR's crappiest pumps (when REI owned the company) failed and I got a fireball out of it!!! I simply turned a bucket upside down over the stove, and that took care of it! Now, I only use the good MSR pumps, and wouldn't even consider using one of the pumps from when REI was cheaping them out, and making them dangerous!!

    I began using Optimus 111B's, and 22B's many decades ago, and again, no problems. Once, I did see a 111T pump rod begin to slowly rise, which is a signal that the NRV is leaking. So, I quickly turned off the stove, and when it was cooled down, changed the NRV and it tested fine. So, I restarted the stove, and continued cooking my meal. Other than that. Those stoves are, IMHO, safe to use with Coleman Fuel, and also, for the "T" models, with Meths, IF they are regularly and properly maintained!! Those models of stoves have been used and trusted here in the US since they first were offered here. Others obviously have a different opinion than mine, and that's no problem. I trust these stoves with gas, not because of someone's opinion, but because lf my long experience with the stoves and that fuel!! For what it's worth.... Take care, and God Bless!

    Every Good Wish,
    Doc (who loves Meths, Kerosene, and also Coleman Fuel!!)
     
  9. pyro_P Australia

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    ^^^What Doc Mark said. I would trust hands on experience more, than I read it on the internet.
    The pump rod starting to protrude while burning, is the first sign of a problem.
    If uncertain, remove the NRV, fit a new pip & the stove will be good for a lot more years.
    By the way, in my opinion, you have purchased a fine stove.

    EDIT: you do realise, this stove runs well on kerosene?
     
    Last edited: Dec 6, 2019
  10. Cookie

    Cookie United States Subscriber

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    Amen to that snwcmpr
     
  11. Harder D. Soerensen

    Harder D. Soerensen Denmark Subscriber

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    +1 on @Doc Mark (without his many years of experience ;-)) and @pyro_P remarks regarding the “tell-tale signs” of the moving pump rod.
    I recently sat down in the woods on a small hike and had a brew on my Juwel 34 wondering what would happen if the SRV would blow as the stove was running on full throttle - when it suddenly caved in. It gave a small flame on around 10 cm lenght out of the tin and had me quickly turning the stove off and I could just blew the flame out. (Bad breath?)
    Glad it didn’t happen during a dry summer though - but nothing scary.
    Almost the same happend on my newly aquired Vesta. I had checked the filler cap seal which seemed soft and OK, but during the first brew in the woods, that seal just melted like if it was made of old gummy bears = an app. 15 cm. flame shot out from the filler cap and I repeated the same procedure as with the Juwel.
    I have a deep respect for these volatile fuels, but I am not afraid of them.
    Saying no to CF stoves would also remove quite a bit of the small camping/army stoves from my small collection, which I like very much.
     
  12. Skopar

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    Tron, your explanation about Katadyn changing in 2010 the place of the NRT, in a way that it can only expell air/vapour if they fail, as it happens also with the Colemans, is very interesting. If that was case for the latest Hiker+ stoves, it would make them as save to use with gasoline, as the Colemans. 2010 is before the second generation of Optimus Hiker+, with a brass tank (and a much higher sale price) came to the market. So the posibility that the technology had been implemented into the Hiker+ model that has a brass tank seems plausable and worth researching. I am going to ask Katadyn. If I learn something about it, I'll post it back on this thread. Thanks a lot for your help guys!
     
  13. HunterStovie

    HunterStovie United States Subscriber

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    Just my 2 cents,

    I've had more o-rings fail than NRV pips, and the failed o-rings leaked way more fuel. Luckily all of the leaks were caught in time which is why you should never leave a stove unattended. I also always pump up the tank the night before a trip to make sure all is good if I have not used the stove in a while and I have not had a problem with any stoves that have had the seals and pips replaced by me. I understand the risks involved with using Coleman fuel and accept those risks.

    Mike
     
  14. Odd

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    Personally I find it highly questionable Katadyn would do such a modification to what is in essence a 111 (original 11 even) tank design;
    the pump tube is solidly fitted into the tank - how would a change-out of the NRV be done if it is in any other accessibility direction than straight down?!? And remember, the Hiker+ production were on its very last legs during the 2010's (final production ended - was it last year?)…
    /Odd
     
  15. theyellowdog

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    On a 111, a NRV mounted on top of the pump tube, pointing up, would still have the NRV seal submerged in the fuel.
     
  16. Marc

    Marc Subscriber

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    $10 Amazon endoscope will tell the tale about the 111.
     
  17. Tron

    Tron Subscriber

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    I strongly doubt it too, but it can not be more difficult to apply than the Coleman system, mount the NRV inside the pump tube and let the tube taper down and bend up to the top of the tank.

    Tron
     
  18. itchy

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    Last edited: Dec 10, 2019
  19. snwcmpr

    snwcmpr Subscriber

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    Not meaning to feed the debate, but, fumes are more a problem than just liquid.
    Having the NRV above the level of the liquid does not negate the concerns.
    Safe usage is a learned trait. People learn it from places like this forum. Kudos for sharing the topic.
     
  20. afoton

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    I am more concern of liquid. Because the same leak will leak alot more liquid than fumes, and what vapurised inside the tank will also wapurise inside the pump. So leaking liquid will makes alot more fumes than leaking fumes. Otherwise the safety valve should also be at the bottom of the tank…