Hard- Surfacing, Building Fusion Welding Carbon Welding Non-Ferrous Metals Heating & Heat Treating Braze Welding Welding Cast Iron Welding Ferrous Metals Brazing & Soldering Equipment Set-Up Operation Equipment For OXY-Acet Structure of Steel Mechanical Properties of Metals Oxygen & Acetylene OXY-Acet Flame Physical Properties of Metals How Steels Are Classified Expansion & Contraction Prep For Welding OXY-Acet Welding & Cutting Safety Practices Manual Cutting Oxygen Cutting By Machine Appendices Testing & Inspecting
6 Tighten all hose connection nuts with a wrench. Test all connections for leaks. First, close both torch valves. Then turn in the pressure-adjusting screw on the oxygen regulator until its delivery-pressure gauge reads about 25 psi (172 kPa). Turn in the pressure-adjusting screw on the acetylene regulator until its delivery-pressure gauge reads about 10 psi (69kPa). Using a suitable leak-test solution and a brush (you can buy such a solution ready-made, or make up your own by dissolving Ivory soap in water), check for leakage (which will be indicated by bubbling) at the cylinder valves, the cylinder-to- regulator connections, and at all hose connections, as indicated in Fig. 6-7. If leakage is detected at either cylinder valve stem, close the valve, release the pressure-adjusting screw on the regulator, remover the regulator from the cylinder, and return the cylinder to your supplier, as directed in Chapter 3. If a leak is detected at either cylinder-to- regulator connection, close the cylinder valve, tighten the regulator connection nut with a wrench once more, re- open the cylinder valve, and test again. If a leak is detected at any hose connection, retighten the connection nut with a wrench and retest. If any connection fails to pass the second test, release all pressure from that side of the system (oxygen or acetylene). To do this, close the cylinder valve, release the regulator pressure-adjusting screw, open the torch valve, and finally turn in the regulator pressure-adjusting screw until no pressure is indicated on either regulator gauge. Then break the leaky connection, inspect the mating seats carefully for nicks or foreign particles which may be the source of trouble. If none can be seen, wipe both seats carefully with a clean cloth, remake the connection, and retest after restoring pressure. To check for leakage through the torch valves you should, after making sure that all other connections are leaktight, dip the torch tip or nozzle in water, or place leak-test solution across the tip or nozzle orifices. If bubbling occurs, open and close each torch valve rapidly to see if that will stop the leakage. If it does not, replacement of one or both torch valve stem assemblies, or reseating of the torch body, may be necessary. After lighting the torch (as directed hereafter) you should use leak-test solution to check for leakage around the torch valve stems, and tighten the valve packing nut or nuts as needed to stop the leaks. Continued on next page...