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AC/OX CUTTING/WELDING/BRAZING Operating instructions for Cutting Torch a. All valves are shut at the commencement of work: Cylinder valves (1 and 2) are shut, the regulator adjusting screws (3 and 4) are screwed so far out that they run freely on their threads, and all torch valves(5, 6, 7 and 8) are closed.

i. Press down the cutting Oxygen lever (8) and readjust to normal flame by means of the valve for preheating Oxygen (7). The torch is now ready for cutting. NB. When cutting, the torch Oxygen needle valve must be kept fully open.

b. Select the cutting nozzle (9) to suit the type and thickness of the workpiece. The required nozzle and working pressure for mild steel when using 6 mm (1/4”) hoses 10 m long are given in the cutting table. Other materials and hoses may require other nozzles and working pressures than those given in the table.

j. In the event of sustained backfire, which is recognized by a whistling or hissing sound, first close the valve for preheating Oxygen (7) as quickly as possible, releasing the cutting Oxygen valve lever (8) at the same time. Then shut the torch Acetylene needle valve (6).

c. Slowly open the cylinder valves for Oxygen (1) and Acetylene (2). d. Fully open the torch Oxygen needle valve (5) and the valve for preheating Oxygen (7). Then press the cutting Oxygen valve lever (8), and adjust the working pressure by means of the Oxygen regulator adjusting screw (3).

e. Release the cutting Oxygen valve lever (8) and shut the valve for preheating Oxygen (7). f. Fully open the torch Acetylene needle valve (6), and adjust the working pressure by means of the Acetylene regulator setting screw (4).

g. Slightly open the preheating Oxygen valve (7) to provide a little extra Oxygen to prevent troublesome sooting when the torch is lit.

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h. Light the torch and adjust to neutral flame, using the valve for preheating Oxygen (7).

k. The torch is normally extinguished by first closing the torch Acetylene needle valve (6) and then the valve for preheating Oxygen (7). Finally, relieve the pressure in the hoses and close all valves.

Important

I. After finishing work, release the pressure in the hoses by closing the cylinder valves (1 and 2) and empty one hose at a time, keeping the torch needle valve for the other gas shut. Finally, make sure that all torch valves are shut, and unscrew the regulator adjusting screws (3 and 4) so far that they run freely on their threads.

2. Check the sealing rings at regular intervals for damage, deformation or wear. Replace them if they are defective. To facilitate changes of torch or cutter tips, the sealing rings and sealing surfaces in the torch connection head should be lightly smeared with a special lubricant.

Oil or grease must never be used.