The mixture is heavier than air, low-toxic (toxicity refers to the fourth group), has a pronounced odor at a concentration of 1:100 mg / m 3 .
IAF is available in propane cylinders (red) for liquefied gases (GOST 15860-84) equipped prokalovym gear.
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| Methylacet |
- in general safety precautions when working with the IAF must comply with safety precautions used when working with propane;
- LPG explosion and fire, explosion limit in air is IAF 3,4-10,8% oxygen - 2,5-60%;
- avoid contact with the IAF alloys containing more than 65-67% of copper, as this may lead to the formation of explosive acetylides of copper;
- in contact with the human body liquefied gases can cause frostbite of the skin;
- at concentrations in the air more than 300 mg / m 3 can have a mixture of LFA anesthetic effect;
- at low concentrations of vapor in air using IAF filter masks, and at high concentrations - insulation hose masks with forced clean air;
- production facilities must be equipped with forced ventilation.
As a substitute for acetylene LFA can be used in gas welding, cutting and surface separation , soldering , plating and other processes of flame treatment of metals. At the same time apply a little modernized acetylene torches and cutters. The outlet orifice reams drill 3 mm in diameter to a depth of 3.5 mm. Due to this increased heat output of the flame, and ensures a more stable mode of the burner flame job.
Effective temperature of the combustion flame zone IAF (2927 ° C) is close to the temperature of the acetylene flame (3087 ° C). MAF saves a lot of heat transfer on the heated metal, even at a distance of 12 mm from the hottest point of the flame.
Depending on the ratio of oxygen flow to the IAF
beta = V O 2 / V IAF
Flame LFA (as well as any hydrocarbon flame) can be
- carburizing (recovery), β ≤ 2,2;
- normal (neutral), β = 2,3-2,5;
- oxidation, β> 2,5.
When welding with a mixture of the LFA as a filler material is usually used wire marks SV08G2, SV08GS, SV08G2S, SV12GS.
When welding low carbon steel gas flow rate is determined by the IAF by the formulas:
V = (60-70) δ - method for the left gas welding;
V = (75-90) δ - for the right way to gas welding,
where δ - thickness of the metal (welded edges), mm.
TABLE. Some comparative characteristics of the IRF-gas, acetylene and propane
| Parameter | IAF | acetylene | propane |
| The sensitivity to impact, safety | stable | unstable | stable |
| Toxicity | minor | ||
| Explosive limits in air (%) | 3,4–10,8 | 2,2–81 | 2,0–9,5 |
| Explosive limit for oxygen (%) | 2,5–60 | 2,3–93 | 2,4–57 |
| The temperature of the flame | 2927°С * | 3087°С | 2526°С |
| Reaction with conventional metals | Avoid alloys with a copper content of more than 65-67% | Avoid alloys with copper content over 70% | minor restrictions |
| The tendency to kickback | minor | significant | minor |
| The rate of combustion in oxygen (m / s) | 4,70 | 6,10 | 3,72 |
| The gas density at 0 ° C (kg / m 3) | 1,70 * | 1,17 | 2,02 |
| The density of liquid at 15,6 ° C (kg / m 3 ) | 575 | – | 513 |
| The ratio of oxygen consumption to fuel gas (m 3 / m 3 ) in the normal flame | 2,3–2,5 | 1–1,2 | 3,50 |
| * - data "Naftan" plant "Polymir" (Belarus), a manufacturer of IAF | |||
| Thickness | Application rates on the 1st of the weld | |||
| The mass of weld metal (kg) | The mass of the filler wire (kg) | (m 3 ) | Oxygen (m3 ) | |
| no groove | ||||
| 1 | 0,028 | 0,029 | 0,013 | 0,030 |
| 1,5 | 0,040 | 0,051 | 0,023 | 0,053 |
| 2 | 0,070 | 0,074 | 0,034 | 0,078 |
| 2,5 | 0,084 | 0,088 | 0,044 | 0,101 |
| 3 | 0,094 | 0,103 | 0,051 | 0,174 |
| for joints butt joints with a Y-shaped groove | ||||
| 3 | 0,123 | 0,140 | 0,063 | 0,145 |
| 4 | 0,178 | 0,187 | 0,104 | 0,240 |
| 5 | 0,224 | 0,235 | 0,139 | 0,320 |
| 6 | 0,265 | 0,278 | 0,197 | 0,450 |
gas welding technology
flame cutting
types of gas cutting
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