PYRO, domestic roarer, ~1910(?)

Discussion in 'AB Pyro' started by SMolson, Aug 28, 2013.

  1. SMolson

    SMolson Subscriber

    Feb 24, 2009
    A PYRO stove, not numbered, brass, 2 quart, domestic, roarer burner circa 1910.

    Some information (opinion, lol) here about these types. She came complete, but no prickers, instructions and the flame spreader was not original to the stove - it was Primus labelled. As a result it did not sit properly on the burner's rim and was a tad high/tight to the burner.

    This stove saw very little use, she was in great shape, no dings or scratches, wonderful patina so she won't need to be cleaned or polished up (phew).

    At first look (and second...) she's a very attractive, unique stove in design and size.

    A lot about her goes against convention, but she performs very well. Nice tank markings include the large 'PYRO' stamping, 'MADE IN SWEDEN', AKTIEBOLAGET PYRO STOCKHOLM.

    And 'PATENT'. No markings on her side or spirit dish.

    PYRO-labelled roarer burner, reversed from the norm flame spreader support (lowered outside perimeter, raised center)

    Horse-shoe shaped, shallow spirit dish with venting hole.

    The longest (and most impressive) venting screw I've seen. Right through one of her pot supports/legs with a t-bar in place to prevent loss and nice wooden handle.

    Fuel/pump cap (one in the same) labelled 'PYRO PATENT' with a star logo separating each word. Unlabeled pump handle, pump rod is steel.

    Standard knurling.

    The pump rod assembly is in 2 main parts, much like that from a Coleman/Aladdin M-1950, M-1942, some Enders models, etc. To fuel her you have to remove the assembly from the tank. Unscrews and pulls out.

    Spring on the steel pump rod, original washer was dried out and replaced.

    Pump cup is leather, NRV on the outside of the pump cylinder for easy access. Luckily this one's PIP/spring were fine and did not need to be replaced (or the NRV even unscrewed).

    I don't think this particular model was used much but was well taken care of/stored. Her pump leather is still in great shape and it did not need to be replaced. Interesting assembly and manner of locking it in place.

    Keeping to the originality of her design, the legs were flattened steel (allowing for that hole to be drilled for the venting screw).

    Underside of her fuel tank is unmarked, but it's also the unusual storage location for her fuel cap (for use if you don't want to pump the stove, e.g. marketed as 'pumpless' and 'efficient on fuel').

    Fuel cap labeleled like her pump cap: 'PYRO PATENT'. Original washer had long since dried to hard clay and it was replaced with one cut from 1/16th" viton.

    After pressure tests, washer replacement, etc she was deemed operational to run. To test her ability to self-light and her tank 1/2 full of kero, I kept the vent screw closed and primed her once (no pumping).

    Within 15 seconds, some sputtering, more flames as the fuel rushed to escape the increasing pressure. Her somewhat 'squat' design and short burner to tank distance helped heat the tank quickly and generated pressure.

    After a few minutes (5), her flame gradually (e.g. very slowly) gathered strength. This all with no pumping. That is why they describe it as fuel efficient (low heat/flame output when not pumping)

    I put a kettle on to boil for Chinese green tea, and unlike most other common burners the space between top pot support and burner on this one was very slim, maybe .4 cm. With the mis-matched flame spreader it was dwindled to .25. This resulted in a flattened flame pattern. Any lower and it would have been problematic. Perhaps these were designed to be used with a pan ring? The horizontal length of the pan supports (very short) would also lean one to conclude the same.

    Underside showing the squashed flame pattern.

    Despite that problem, she boiled up 3/4 liter of water in typical time, 4-5 minutes. She never lost pressure or flame intensity, but I cheated and 1/4 way through the boil time I did pump the stove to increase the heat output. The flame intensity/audio grew and she ran as well as any other pump-enabled stove. She worked very well, and to extinguish the flame you open the vent screw which forces vaporized fuel out into the combustion area above the jet and the flame went out, no big bang or fireworks display (I was at least hoping for the latter).

    I really like this stove, good performer, nice unique design, meets the performance attributes described in the review. I find it funny how they would include a fuel cap when if the user did not want to pump they, well, would just not pump. They don't have to replace the pump cap with the non-pump cap, lol. Because of how high the burner sits in relation to the pot supports, it would not be my first choice for single-burner cooking models. It may be problematic for some lower-pot bellied pots (unless I find a pan ring for her).

    Otherwise a big thumbs up from me (always pulling for the underdog). :thumbup:
    Last edited by a moderator: Jul 2, 2015
  2. Klasse

    Klasse Subscriber

    Jun 27, 2013
    That´s a really nice stove Stephen!

    Sometimes I got a feeling that you have a wekness for swedish stoves. ;) :thumbup:

  3. loco7stove

    loco7stove Subscriber

    Sep 30, 2010
    Great stove & super flame shots 8) :thumbup: , a very nice find indeed , well done :D :thumbup:

    Stu :mrgreen: :thumbup:
  4. Sparky

    Mar 20, 2010
    Houston, Tx area
    Great photos of a very interesting stove!
  5. SMolson

    SMolson Subscriber

    Feb 24, 2009
    Thanks, and yes I was impressed with her too. Reading other PYRO postings I had the impression they were slightly poo-pooed a bit, awkward and more for marketing, etc. But she surprised me and performed well, up to published specs. Quality constructed like most Swedish stoves, innovaed design, etc. Perhaps she was too ahead of her time which led to poor(?) sales and the demise of the company. She's with good company if that's the case.

    Edit: Klas - ha ha, yup, must have been a Viking in a past life.
  6. optipri

    optipri Subscriber

    Oct 28, 2005
    I agree, indeed an interesting stove. And it also has an interesting history. In these days Primus was the most sold brand but a man named Paul Urbanus Bergström, who was running a big department store named PUB in Stockholm, descided to compete with Primus. So he ordered some engineers to invent an even better stove that he was planning to sell himself. The stove migh be more effective, not for sure though, but some accidents when the stove exploded ended the story for this model. I guess it was in production for a few years only but a number has been made as we have seen some here at CCS.
    As information I can tell that the Pyro company also made blow torhes and carbide lamps in the beginning of the 1900:s

  7. Christer Carlsson

    Christer Carlsson Moderator SotM Winner

    Nov 12, 2005
    And those "non-dripper" carbide lamps from Pyro are some of the easiest to run and maintain.
    Not the prettiest, but very simple and reliable.
  8. SMolson

    SMolson Subscriber

    Feb 24, 2009
    Because of the shortened distance between burner/pot, if they were not designed to be used with a pan ring perhaps PYRO had their own set of specialized pots to support it? A type with a lowered edge to sit on and catch the pot leg rim properly and a bellied up (e.g. concave) pot/fry pan to coddle the burner flame? I have a little English(?) alcohol trench stove with similar pot supports and its cup has a carved out bottom to sit on it properly. Also similar to a Primus 71 K with her pot supports. Or perhaps they just thought it would be more efficient to keep the burner as close as possible to the bottom of the cooking vessel.