Gases
Acetylene gas — dissolved acetylene (DA) made and filled by KIGL since 1947
Dissolved acetylene (DA) gas is acetylene (C₂H₂) held in solution in acetone inside a porous-mass cylinder; it is the hottest common fuel gas, burning at about 3,100 °C with oxygen. KIGL has made it in India since 1947 at ≥98 %, its own specification, conforming to IS 308 for impurities.
By Mithillessh Garg, Director (Gas Supply)
₹350 – ₹450 per Nm³ Indicative. Your quotation is the figure that counts — price moves with quantity, cylinder size, contract term and delivery.
What acetylene gas is
Acetylene (C₂H₂) is a hydrocarbon gas of two carbon atoms joined by a triple bond. That bond is what makes it useful and what makes it dangerous. Breaking it releases more energy than any other common fuel gas, which is why an oxy-acetylene flame reaches about 3,100 °C and nothing else in a workshop gets close. The same bond lets acetylene decompose on its own, with no oxygen present, which is why IS 14814 : 2023 limits free acetylene to 0.62 bar g and the gas is never compressed like oxygen or nitrogen. It is dissolved in acetone, held in a porous mass that fills the cylinder, and the industry calls the result dissolved acetylene, or DA.
Industrially, acetylene is made by reacting calcium carbide with water in a generator, then cleaning and drying the gas before it is compressed into cylinders. KIGL does both halves of that: it builds the acetylene gas plants and it fills the gas at its own works.
Three grades of acetylene gas
| Grade | Purity | Solvent | Made for |
|---|---|---|---|
| Industrial dissolved acetylene (this page) | ≥98 % (KIGL spec) | Acetone | Cutting, welding, brazing, flame heating |
| High purity acetylene | 99 % | DMF | Processes industrial grade is not clean enough for |
| Ultra-high-purity acetylene | 99.99 % | DMF | Atomic absorption spectroscopy and analytical work |
The grades differ in how far the gas has been through purification and, at the top, in the solvent. Everything KIGL publishes on acetylene, from the plants to the standards and the handling guides, is collected on the acetylene hub, and the short answers are on the industrial gases FAQ. Buying analytical grade for a cutting torch wastes money; running industrial grade through an instrument ruins results.
Dissolved acetylene specification to IS 308
KIGL Industrial Acetylene is generated from calcium carbide, purified and dissolved in acetone at KIGL's PESO-approved Noonmati works. It conforms to IS 308 : 2024 and is filled to KIGL's own specification of ≥ 98.0 % C₂H₂, into acetone-charged porous-mass cylinders built to IS 7312. Phosphine and hydrogen sulphide are the two impurities that carry over from the calcium carbide, and both are removed in the purifying chamber of the generating plant; KIGL fills inside the IS 308 limits for each. The full table of properties, values and their basis is set out below.
Higher purity is available on special order. The standard industrial fill is ≥ 98 %, which is KIGL's own specification — IS 308 caps impurities rather than setting a minimum assay — and it is what cutting, welding and flame heating need. Where a process needs cleaner gas than that, KIGL can supply dissolved acetylene up to 99.99 % on special request for specialised applications — the purity KIGL-built plants already produce — against a specific enquiry: state the purity the process needs and the volume, and KIGL will confirm what it can hold and on what lead time.
Need cleaner flame chemistry? KIGL also fills ultra-high-purity acetylene in DMF for atomic absorption spectroscopy and synthesis.
Filling pressure and cylinder pressure are two different numbers. KIGL fills at 20 bar g at the filling line, which is a process figure for the compressor and manifold. What matters in use is the pressure that settles in the cylinder as received, and that is capped by IS 14814 : 2023 cl 7.2.2 at 15.495 atm, about 14.7 bar g, for a cylinder charged at 15 °C with acetone; Miller (1965, Acetylene Vol. 1) agrees at roughly 15 atm for a full charge. A dissolved acetylene cylinder is not a high-pressure cylinder. Most of the inflated pressures quoted for acetylene in trade literature are a filling-line figure of this kind that has been copied across as though it were the pressure in the cylinder. Specify and design against 15.495 atm.
Acetylene physical properties
| Property | Value |
|---|---|
| Molecular weight | 26.04 |
| State in cylinder | Dissolved gas, in porous mass (in acetone) |
| Sublimation point at 1 atm | −84 °C |
| Liquid density at boiling point | 0.617 g/ml |
| Gas density at 20 °C, 1 atm | 1.09 kg/m³ |
| Relative density (air = 1) | 0.91 |
| Vapour pressure at 20 °C | 44 bar absolute |
| Flammability limits in air | 2.5 % to 82.0 % |
| Autoignition temperature | ≈305 °C |
| Flame temperature in oxygen | ≈3,100 °C |
The 2.5 % to 82.0 % range is the widest of any common industrial gas. Almost any leak that mixes with air at all produces an ignitable atmosphere, which is why ventilation and leak testing matter more with acetylene than with any other fuel gas on a site.
Acetylene applications in welding, cutting and thermal work
One flame, many trades. KIGL Industrial Acetylene covers the full range of hot work.
Setting the flame, the lighting order and the pressures are covered in oxy-acetylene welding and cutting.
Welding and cutting
- Oxy-acetylene welding and brazing of steels and alloys
- Profile cutting of plates and sections
- Gouging and scarfing
- Flame straightening and localised heating
Surface and thermal
- Flame hardening of wear surfaces
- Hardfacing and thermal spraying
- Flame cleaning and descaling
- Carbon coating of moulds and dies
Control equipment is available from KIGL: two-stage brass acetylene regulators with left-hand connection, flashback arrestors for regulator and torch ends, and welding and cutting torch sets.
An acetylene cylinder cascade, manifolded to a single regulated take-off
Guwahati works · agent network
Acetylene gas cylinder: colour, pressure, capacity and refill
| What buyers ask | Answer |
|---|---|
| Acetylene gas formula | C₂H₂ — two carbon atoms, two hydrogen atoms, one triple bond |
| Cylinder colour in India | Maroon body, to IS 4379 |
| Cylinder standard | IS 7312 : 2018, porous mass with acetone |
| Cylinder pressure | 15.495 atm at 15 °C (≈14.7 bar g) is the maximum IS 14814 permits. The gauge reads acetone vapour pressure, not contents |
| How much gas is inside | By weight: cylinder weight minus the tare stamped on the shoulder |
| Working line pressure | Never above 0.62 bar g free acetylene, per IS 14814 |
| Refill | Exchange at the Guwahati works or through an agent; cylinders are weighed in and out |
| Hydrostatic retest | Every two years for the cylinder and porous mass, under the Gas Cylinders Rules |
A dissolved acetylene gas cylinder is not an empty steel bottle. It is packed with a porous mass soaked in acetone, and the gas is dissolved into that acetone at filling. That is why it is heavy for its size, why it must stand upright, and why the pressure gauge tells you the temperature of the cylinder far more than how much gas is left. The cylinder handling guide covers storage, transport and use in detail.
Acetylene gas price in India
Indicative ex-works price for industrial dissolved acetylene from KIGL is ₹350 to ₹450 per Nm³, as published above. Six things move it: quantity and contract term, cylinder size and whether the cylinder belongs to the customer or to KIGL, the grade (99 % and 99.99 % carry their own prices), distance from the Guwahati works, carbide cost, and the current PESO and transport charges. A quotation states the basis, so two quotes can be compared on the same footing. The industrial gas prices guide sets the acetylene figure beside oxygen, nitrogen, argon and CO₂.
Safe handling
Safe handling of acetylene cylinders
- Never exceed 0.62 bar g line pressure — the normal limit for free acetylene under IS 14814 : 2023. A maximum of 1.03 bar g (15 psig) applies only with special safety measures and clearance from the Chief Controller of Explosives. Free acetylene can decompose explosively with no oxidant present.
- Withdraw no more than 1/7th of cylinder contents per hour in continuous service; manifold multiple cylinders for high flows.
- Keep cylinders upright in storage, transport and use, to prevent liquid solvent withdrawal.
- Fit flashback arrestors at both regulator and torch; open the valve no more than 1.5 turns.
- Store ventilated, away from oxygen and oxidiser cylinders, heat and ignition sources.
- Leak-test with soap solution, never a flame.
Full hazard data is in the acetylene safety data sheet; the governing standards are set out on acetylene standards.
Acetylene gas manufacturer in India since 1947
KIGL and The Industrial Gases Limited before it have generated, purified and filled acetylene in India for 79 years. The gas is made at KIGL's own PESO-approved works at Guwahati (Assam), in single cylinders and in cascades sized against measured draw-off rather than total consumption, and supplied beyond its delivery radius through a network of agents across Uttar Pradesh, Madhya Pradesh, West Bengal, Assam, Odisha and other states.
Cylinder exchange and refill programmes are available for regular users. KIGL does not supply liquid or cryogenic acetylene, and nor does anyone else: the product is not stable in that form.
KIGL was formed in 1988 from The Industrial Gases Limited, founded in Calcutta in 1947. The acetylene on this page is made and filled by KIGL at Guwahati.
Why KIGL
Why buy dissolved acetylene from KIGL
Acetylene since 1947, and KIGL builds the plants that generate it as well as filling the gas. Devendra Kumar Garg, KIGL's founder, has sat on the Bureau of Indian Standards committees that draft the standards for acetylene cylinders and generators since the 1970s, and was Convener of the dissolved acetylene cylinders and generators subcommittee for IS 15190 : 2002.
That matters at the point where something is wrong with your gas: the person answering has run a generator, filled cylinders from it, and answered to an inspector about it.
The works holds PESO licences in Forms E and F of the Gas Cylinders Rules for filling and storing dissolved acetylene, first granted in 1984 to The Industrial Gases Limited and transferred to KIGL, alongside separate licences for the calcium carbide and the acetone. The numbers are published on approvals and licences. Indicative pricing and what moves a gas quotation are on the industrial gas prices guide.
Specification
Acetylene gas — full specification
| Property | Value | Basis |
|---|---|---|
| Specification | IS 308 (Dissolved Acetylene) | Bureau of Indian Standards |
| Purity | ≥98 % v/v | KIGL fill specification |
| Solvent | Acetone | IS 7312 : 2018 |
| Cylinder pressure, settled | 15.495 atm at 15 °C (≈14.7 bar g), per IS 14814 | IS 14814 : 2023 cl 7.2.2 |
| Cylinder standard | IS 7312 : 2018 | Bureau of Indian Standards |
| UN number | UN 1001 | ADR 2025 |
| HSN code | 2901 29 | India GST tariff |
| Chemical formula | C₂H₂ | — |
| Purity, special order | Up to 99.99 % v/v | KIGL, against a specific enquiry |
| Phosphorus compounds (as PH₃) | ≤ 100 ppm (0.01 % v/v) | IS 308 : 2024 Table 1 limit; purified in the generating plant, batch checked |
| Sulphur compounds (as H₂S) | ≤ 200 ppm (0.02 % v/v) | IS 308 : 2024 Table 1 limit; purified in the generating plant, batch checked |
| Impurities insoluble in acetone | ≤ 4 % v/v | IS 308 : 2024 Table 1 limit |
| Moisture | ≤ 0.25 % by mass | IS 308 : 2024 Table 1 limit; low- and high-pressure drying stages |
| Cylinder charge | Porous mass, acetone-charged | IS 7312 : 2018 |
| Cylinder pressure, settled maximum | 15.495 atm at 15 °C with acetone (≈14.7 bar g) | IS 14814 : 2023 cl 7.2.2 |
| Filling pressure, at the filling line | 20 bar g | KIGL process specification, confirmed 14-Oct-2026 |
| Flame temperature with oxygen | ≈3,100 °C | Miller (1965), Acetylene Vol. 1, Table VII.11 — 3,114 °C calculated for the neutral flame |
| Cylinder colour | Maroon | IS 4379 |
Documents
Acetylene gas — safety and technical documentation
Questions
Acetylene gas — frequently asked questions
Who manufactures acetylene gas in India?
Acetylene is made close to where it is used, because a dissolved-gas cylinder is heavy and travels badly. India therefore has many regional fillers and only a few companies that both generate the gas and build the generating plant. KIGL is one of them, manufacturing acetylene since 1947, filling at its own PESO-approved works at Guwahati, and building acetylene plants that ship anywhere in India.
Why is acetylene dissolved in acetone rather than stored as compressed gas?
Acetylene decomposes explosively under pressure on its own — it does not need oxygen to do so. Dissolving it in acetone, held inside a porous mass that fills the cylinder, keeps it stable. This is why an acetylene cylinder is heavy, why it must be used upright, and why it can never be filled like an ordinary compressed gas.
Why must an acetylene cylinder be used upright?
Lying it down lets liquid acetone reach the valve. The acetone is then drawn off with the gas, which starves the porous mass, contaminates the flame and damages downstream equipment. If a cylinder has been horizontal, stand it upright and leave it for at least an hour before use.
What is the maximum rate I can draw from one cylinder?
Draw-off is limited, because withdrawing too fast pulls acetone out with the gas. Exceeding the safe rate destabilises the flame and reduces the protection a flashback arrestor can give. Where a high continuous rate is needed, use a cascade rather than a single cylinder; KIGL sizes these against the stated consumption.
What acetylene grades do you make?
Three. Industrial dissolved acetylene at 98 % in acetone, conforming to IS 308, for cutting, welding, brazing and flame heating. High purity at 99 % in DMF, where industrial grade is not clean enough but analytical grade is more than the job needs. And ultra-high-purity at 99.99 % in DMF, for atomic absorption spectroscopy and analytical work. Buying the analytical grade for a cutting torch wastes money; using industrial grade on an instrument ruins results.
Can I use my propane regulator and hoses with acetylene?
No. Acetylene equipment uses different thread forms, materials and pressure ranges, and acetylene attacks copper and high-copper alloys to form explosive acetylides. Use acetylene-rated equipment throughout, keep it free of oil and grease, and fit flashback arrestors and non-return valves.
Do you supply liquid acetylene or bulk tankers?
No. Liquid acetylene does not exist as a commercial product — it is unstable. KIGL supplies dissolved acetylene in cylinders and cascades only.
How do I know how much gas is left in the cylinder?
Not from the pressure gauge, which reads the acetone vapour pressure rather than the gas remaining, and which varies with temperature. Weigh the cylinder and compare against the tare weight stamped on the shoulder. The difference is the acetylene left.
References
- Bureau of Indian Standards. (2002). Acetylene pipelines (IS 15190:2002).
- Bureau of Indian Standards. (2018). Welded and seamless steel dissolved acetylene gas cylinders — Specification (IS 7312:2018, Third Revision).
- Bureau of Indian Standards. (2021). Identification of the contents of industrial gas cylinders (IS 4379:2021, Second Revision).
- Bureau of Indian Standards. (2023). Acetylene — Code of safety (IS 14814:2023, First Revision).
- Bureau of Indian Standards. (2024). Dissolved acetylene (gas) — Specification (IS 308:2024, Fourth Revision).
- Government of India. (2016). Gas Cylinders Rules, 2016 (G.S.R. 1081(E)). Petroleum and Explosives Safety Organisation.
- Miller, S. A. (1965). Acetylene: Its properties, manufacture and uses (Vol. 1). Ernest Benn.
- The Kamrup Industrial Gases Limited. (2026). Company information and manufacturer's data [Company statement].
Read next
Enquiries
Request a quotation for acetylene gas
State the gas or equipment, the quantity or capacity, and your location. KIGL will confirm the grade, the cylinder or plant size, and whether the location can be served from Noonmati, or through the agent network.