Gas welding and cutting equipment is safe, provided it is controlled and used in accordance with the manufacturer's instructions. Of particular importance are the lighting up and closing down procedures.
1. Check for the following:
- Cylinder valves are closed.
- Regulators are set to zero outlet pressure.
- Torch valves are closed
If regulators show a pressure reading on the gauges or indicators, the relevant gas should be vented to atmosphere by opening the torch valve and screwing in and out regulator pressure adjuster momentarily. This will clear any build-up of pressure.
2. Close torch valve.
3. Open cylinder valves very slowly (sudden opening may cause damage to regulator).
4. Do not open more than one complete turn of valve spindle - this is adequate and will pass all the gas required.
5. Set outlet pressures on regulators in accordance with manufacturer's recommendations.
6. Turning adjusting screw clockwise increases outlet pressure.
The gauges on the regulators have colour-coded dials and the working pressures for various welding purposes are clearly defined.
7. Open oxygen valve on torch for 4 to 5 seconds to clear any air/gas mixture from the system.
8. Close oxygen valve.
REPEAT procedure for ACETYLENE.
9. Open acetylene valve on torch and ignite gas flowing from nozzle by means of a spark lighter (not an open flame).
10. Reduce or increase acetylene flow by means of torch valve until the flame just ceases to smoke.
11. Open oxygen valve on torch and adjust flow until flame has well-defined blue inner cone with the merest trace of a feathery white tip.
This is a "neutral" flame suitable for most oxy-acetylene welding applications.