How to adjust the thimble during gas cutting?
1 Put the guide rail, put the cutting machine on the guide rail, and align both ends of the guide rail. When cutting a circle, adjust the height, distance and angle of the cutting nozzle relative to the trolley to ensure continuous cutting in the plate area.
2 Connect the gas pipeline and distinguish the oxygen pipeline from the gas pipeline.
3 Open the oxygen control valve and gas control valve, and confirm the cylinder pressure and output pressure to ensure adequate and economical gas supply.
4 ignition; Turn on the gas to preheat the oxygen and light it from the side with a lighter.
5. Start cutting; Heat the starting point with preheating flame (at this time, the hyperbaric oxygen valve is closed). The preheating time depends on the metal temperature, and it is generally heated until the surface of the workpiece is close to melting (the surface is orange). Then gently open the hyperbaric oxygen valve and start gas cutting. If the preheating place cannot be cut off, it means that the preheating temperature is too low, and the hyperbaric oxygen should be turned off to continue preheating. The front end of the flame center of the preheating flame should be 2 ~ 4 mm away from the surface of the workpiece, and a certain angle should be paid attention to between the cutting torch and the workpiece. When cutting a workpiece with a thickness of 5 ~ 30 mm, the cutting torch should be perpendicular to the workpiece; When the thickness is less than 5mm, the cutting torch can be tilted back 5 ~10; If the thickness exceeds 30mm, the cutting torch can be tilted forward by 5 ~ 10 at the beginning of gas cutting, and can be perpendicular to the workpiece until the gas cutting is completed. If the preheating area is cut off, continue to increase the amount of hyperbaric oxygen to increase the depth of the incision until it is completely cut through.
6. When gas cutting steel with different thickness, the selection of cutting nozzle and the adjustment of oxygen working pressure are closely related to gas cutting quality and working efficiency. For example, if the nozzle is too small to cut thick steel, the cutting work cannot be carried out smoothly because of insufficient oxygen combustion and injection capacity. Even if it is cut again and again, the quality is poor and the work efficiency is low. On the other hand, if an oversized nozzle is used to cut thin steel, it will not only waste a lot of oxygen and acetylene, but also the quality of gas cutting is not good. Therefore, it is necessary to select the size of the cutting opening. The relationship between the pressure of cutting oxygen and the thickness of metal: insufficient pressure not only slows down the cutting speed, but also makes the slag difficult to blow off, and the incision is uneven and sometimes even impenetrable; When the pressure is too high, in addition to the increase of oxygen consumption, the metal is also easy to cool, thus reducing the cutting speed, widening the incision and making the surface rough.