Svea 123: Difference between revisions
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Because the '''Svea 123''' is made of brass and has only one moving part – the control valve (the later Svea 123R model has an additional moving part, the internal self-cleaning needle) – the Svea has a well-established record of reliability and can withstand years of heavy use with only minimal maintenance.<ref> C. Townsend, "The Advanced Backpacker: A Handbook of Year Round, Long-Distance Hiking ," pp. 161-62 (Ragged Mountain Press 2001)</ref> Some users have reported clogging and other operational problems with the self-cleaning needle on the 123R, such as that the stove may not simmer as well as the earlier Sievert models,<ref> R. Wood, “The 2 oz. Backpacker: A Problem Solving Manual for Use in the Wilds,” p.94 (Ten Speed Press 1982)</ref> but reports from years of field use of the Svea on the [[Appalachian Trail]] indicate that it has the lowest record of clogging among stoves used on the trail.<ref> R. Mueser, “Long Distance Hiking: Lessons Learned from the Appalachian Trail,” p.58 (Ragged Mountain Press 1997)</ref> |
Because the '''Svea 123''' is made of brass and has only one moving part – the control valve (the later Svea 123R model has an additional moving part, the internal self-cleaning needle) – the Svea has a well-established record of reliability and can withstand years of heavy use with only minimal maintenance.<ref> C. Townsend, "The Advanced Backpacker: A Handbook of Year Round, Long-Distance Hiking ," pp. 161-62 (Ragged Mountain Press 2001)</ref> Some users have reported clogging and other operational problems with the self-cleaning needle on the 123R, such as that the stove may not simmer as well as the earlier Sievert models,<ref> R. Wood, “The 2 oz. Backpacker: A Problem Solving Manual for Use in the Wilds,” p.94 (Ten Speed Press 1982)</ref> but reports from years of field use of the Svea on the [[Appalachian Trail]] indicate that it has the lowest record of clogging among stoves used on the trail.<ref> R. Mueser, “Long Distance Hiking: Lessons Learned from the Appalachian Trail,” p.58 (Ragged Mountain Press 1997)</ref> |
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Some common but unrecommended practices can adversely affect the Svea’s performance and reliability. For example, when using a wind screen or shield other than the built-in wind screen (such as the flexible aluminum foil windscreens used with stoves made by [[Mountain Safety Research]]), care should taken not to wrap the windscreen too tightly around the stove because this may cause the stove to overheat and the fuel tank to over-pressurize. This in turn will cause the pressure-relief valve on the filler cap to open and the over-pressurized gas vapor to escape, which may catch fire and result in a dangerous "flareup" or large fireball.<ref>“Outfitting,” Backpacker Magazine, p. 101 (June 1997)</ref> In addition, while the Svea is capable of burning [[Gasoline|unleaded automobile gasoline]], only [[ |
Some common but unrecommended practices can adversely affect the Svea’s performance and reliability. For example, when using a wind screen or shield other than the built-in wind screen (such as the flexible aluminum foil windscreens used with stoves made by [[Mountain Safety Research]]<ref>"Stoves: Brand-Specific Hints," Backpacker Magazine, p. 57 (March 1994)</ref>), care should taken not to wrap the windscreen too tightly around the stove because this may cause the stove to overheat and the fuel tank to over-pressurize. This in turn will cause the pressure-relief valve on the filler cap to open and the over-pressurized gas vapor to escape, which may catch fire and result in a dangerous "flareup" or large fireball.<ref>“Outfitting,” Backpacker Magazine, p. 101 (June 1997)</ref> In addition, while the Svea is capable of burning [[Gasoline|unleaded automobile gasoline]], only [[naphtha]] or "[[Coleman fuel]]" is recommended: Coleman fuel contains [[Rust inhibitor|rust inhibitors]] and is specially refined for use in camping stoves, while automotive fuel contains [[Gasoline additive|additives]] that vaporize when burned and leave gumlike deposits behind that causes clogging.<ref>"White Gas vs. Coleman Fuel," Backpacker Magazine, p. 10 (December 1976)</ref> The stove should also not be allowed to run dry because doing so will burn or char the cotton wick inside the fuel tank, which will inhibit the wick’s ability to draw fuel to the vaporizing tube.<ref>J. Fleming, "The Well-Fed Backpacker," p. 53 (Vintage Books 3d Ed. 1985)</ref> |
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== References == |
== References == |
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Revision as of 18:25, 3 January 2010
The Swedish-made Svea 123 is a small liquid-fuel (naphtha, commonly referred to as “white gas” or “Coleman fuel”) pressurized-burner camping stove that traces its origins to designs first pioneered in the late 1800s.
History
Svea stoves were first made by Nybergs Lödlampfabrik, which also manufactured blowtorches as well as other machinery and equipment. Founded by Carl Nyberg, the firm later became one of the largest industries in Sundbyberg, Sweden. In 1922, the business was taken over by Max Sievert, an early associate of Nyberg’s, and renamed Sieverts Lödlampfabrik (later known as Sievert AB). The Svea 123, introduced in 1955, is considered to be the first compact backpacking white gas stove[1] and one of the most popular camping stoves ever made.[2] Its distinctive “roaring” sound has been likened to that of a jet engine at takeoff.[3] In 1970, the Svea brand was acquired by Optimus, another Swedish manufacturer of portable stoves, which continued production of the Svea 123 for another three decades. Because of its simple design[4] and reputation for dependable performance,[5] even under extreme conditions,[6] the Svea 123 enjoys a devoted following.
The popularity of portable camping stoves such as the Svea coincided with the increase during the 1950s and 1960s in the awareness of the environmental impact of backpacking,[7] particularly in heavily-traveled areas,[8] and the rise of the Leave No Trace ethic in the 1970s and 1980s.[9] At the same time, scarcity of fuel in over-used camping areas as well as regulatory requirements (open-fire bans) also contributed to the need for a substitute for open campfires for "wilderness" area cooking.[10] Eventually stoves that were lighter in weight than the Svea, as well as those of other designs that were capable of burning a wider variety of fuels (useful when camping in other parts of the world where white gas is difficult to find) knocked it from its perch as one of the most popular backpacking stoves after nearly 50 years of production.[11] However, the rugged and durable Svea 123 -- often described by long-time users as "bomb-proof"[12] -- still remains popular and continues in wide use.[13]
Construction
Made of solid brass, the Svea 123 weighs about 500 grams (19 ounces), measures 100 mm x 130 mm (3.9” x 5.1”) and will burn for over an hour on full tank (about 4 ounces) of fuel. Later models (designated the “Svea 123R” and also sold as the Optimus “Climber”) were made with a built-in cleaning needle to keep the burner jet from clogging by pushing soot or other impurities outward; early Sievert models without the self-cleaning needle came with a small wire pricker that is used to clean the burner jet manually. These older models are distinguishable by their downwardly-angled spindle, which houses the control valve and to which the adjusting key is attached. The spindle on a Svea 123R with the self-cleaning needle is at a right angle to the stem. A brass windscreen attaches directly to the stove, and has built-in pot supports that fold inward for storage. The aluminum lid comes with a detachable handle and can also be used as a small cook-pot.[14]
How it Works
To light the stove, the fuel tank must first be pre-heated and pressurized by lighting a small amount of fuel poured into the primer pan (a small well) on top of the tank at the base of the vaporizer (the vertical stem connecting the fuel tank to the burner). The tank can also be pressurized by an optional pump that may be attached to the filler cap, but this is generally not necessary except in extreme cold. Fuel from the tank is fed by a cotton wick inside the tank to the base of the vaporizer. The heat and pressure created by the priming flame vaporizes the fuel inside the vaporizer. When the priming flame is nearly burnt out, the control valve is opened by turning the adjusting key. This allows the vaporized fuel to flow under pressure through the burner jet (a small opening at the base of the burner), where it mixes with oxygen and burns with a blue flame. Adjusting the flow of the vaporized fuel that is forced through the burner jet controls the flame size and heat output. The control valve (a spindle) is threaded in the vaporizer's housing, and as it is opened (by turning the adjusting key) it opens like a faucet and the vaporized fuel flows through the burner jet. Closing the spindle closes the fuel supply. A small plate on the top of the burner (a flame spreader) spreads the flame outwards. The heat generated in the burner and vaporizer maintains the internal pressure in the fuel tank.[15][16]
The cleaning needle on the Svea 123R model has two small toothed cogs that face each other, which cleans the burner jet from both the inside and outside when using the stove. The cleaning needle moves upward and downward when the spindle is turned; when the spindle is fully opened, the needle clears the burner jet’s opening. As the spindle is closed, the needle retracts into the burner housing. In this way, any soot that may clog the burner jet is expelled.
Reliability
Because the Svea 123 is made of brass and has only one moving part – the control valve (the later Svea 123R model has an additional moving part, the internal self-cleaning needle) – the Svea has a well-established record of reliability and can withstand years of heavy use with only minimal maintenance.[17] Some users have reported clogging and other operational problems with the self-cleaning needle on the 123R, such as that the stove may not simmer as well as the earlier Sievert models,[18] but reports from years of field use of the Svea on the Appalachian Trail indicate that it has the lowest record of clogging among stoves used on the trail.[19]
Some common but unrecommended practices can adversely affect the Svea’s performance and reliability. For example, when using a wind screen or shield other than the built-in wind screen (such as the flexible aluminum foil windscreens used with stoves made by Mountain Safety Research[20]), care should taken not to wrap the windscreen too tightly around the stove because this may cause the stove to overheat and the fuel tank to over-pressurize. This in turn will cause the pressure-relief valve on the filler cap to open and the over-pressurized gas vapor to escape, which may catch fire and result in a dangerous "flareup" or large fireball.[21] In addition, while the Svea is capable of burning unleaded automobile gasoline, only naphtha or "Coleman fuel" is recommended: Coleman fuel contains rust inhibitors and is specially refined for use in camping stoves, while automotive fuel contains additives that vaporize when burned and leave gumlike deposits behind that causes clogging.[22] The stove should also not be allowed to run dry because doing so will burn or char the cotton wick inside the fuel tank, which will inhibit the wick’s ability to draw fuel to the vaporizing tube.[23]
References
- ^ Outside Magazine, April 2002, “The Gear Years 1875-2002.”
- ^ H. Manning, "Backpacking: One Step At A Time," p.274 (Vintage Books 1980)
- ^ Outsideonline, Nov. 12, 2002, “Gear Guy – Do you know of a camping stove that’s not too noisy?”
- ^ B. Mason, "Song of the Paddle: An Illustrated Guide to Wilderness Camping," p.50 (Firefly Books 2004)
- ^ R. Mueser, "Long Distance Hiking: Lessons learned from the Appalachian Trail," p.58 (Ragged Mountain Press 1997)
- ^ F. Bouwman, "The Practical Camp Book," p.84 (Horizon 1998)
- ^ C. Jensen & S. Guthrie, "Outdoor Recreation in America," p.31 (Human Kinetics 6th Ed. 2006)
- ^ S. Cox & K. Fulsaas, "Mountaineering: The Freedom of the Hills," pp.123-24 (Mountaineers Books 7th Ed. 2003)
- ^ A. McGibney, "Leave No Trace: A Guide to the New Wilderness Etiquette," pp. 29, 31 (Mountaineers Books 2d Ed. 2003)
- ^ M. Mouland, "The Complete Idiot's Guide to Camping and Hiking," p.74 (Alpha Books 2nd Ed. 2000)
- ^ C. Townsend, "The Backpacker's Handbook," p.216, 221 (International Marine/Ragged Mountain Press 2d Ed. 1996)
- ^ C. Latimer, "Wilderness Cuisine," p.65 (Wilderness Press 1991)
- ^ A. Getchell & R. Getchell, "The Essential Outdoor Gear Manual," p.96 (International Marine/Ragged Mountain Press 2d Ed. 2000)
- ^ Optimus Svea 123 Instruction Guide (undated), circa 1983.
- ^ "Backpacking Stoves," Backpacker Magazine, p. 47 (August 1976)
- ^ Optimus Product Guide, p. 6 (undated; circa 1980)
- ^ C. Townsend, "The Advanced Backpacker: A Handbook of Year Round, Long-Distance Hiking ," pp. 161-62 (Ragged Mountain Press 2001)
- ^ R. Wood, “The 2 oz. Backpacker: A Problem Solving Manual for Use in the Wilds,” p.94 (Ten Speed Press 1982)
- ^ R. Mueser, “Long Distance Hiking: Lessons Learned from the Appalachian Trail,” p.58 (Ragged Mountain Press 1997)
- ^ "Stoves: Brand-Specific Hints," Backpacker Magazine, p. 57 (March 1994)
- ^ “Outfitting,” Backpacker Magazine, p. 101 (June 1997)
- ^ "White Gas vs. Coleman Fuel," Backpacker Magazine, p. 10 (December 1976)
- ^ J. Fleming, "The Well-Fed Backpacker," p. 53 (Vintage Books 3d Ed. 1985)