Safety technical measures for gas welding construc

Safety technical measures for gas welding construction of fully mechanized continuous mining face and each air return roadway

I. ventilation management

1. A tile inspector is assigned by the construction team. They have recently completed the production line of high-performance composite decoration materials to detect the concentration of gas and carbon monoxide before and after the abnormal work site and within 20 meters near the switch, When the gas concentration in the air is less than 0.5% and the carbon monoxide concentration is less than 0.0024% at the construction site and within 20 meters near the switch, the welding operation can be allowed. During welding operation, the tile inspector shall measure the gas concentration every 10 minutes, and only the gas concentration is less than 0.5%. At the same time, the operation can be continued only when the inspection proves that there is no gas accumulation at the top of the roadway and behind the supporting backplane within 20m around the operation site. When the gas concentration in the air of the construction site exceeds 0.5%, the operation must be stopped immediately, the power supply must be cut off, the personnel shall be evacuated to the air inlet flow, and reported to the control room for disposal

2. Use rubber hose to connect water to the construction site, and maintain a 20 meter remaining pipe. Before welding, sprinkle water within 10 meters before and after the welding site, and clean the coal accumulation on the bottom plate, live gangue on the top, and combustible debris; During construction, the water spraying personnel must spray water on the construction site at any time, put out the sundries with sparks in time, cool the welded objects, and always keep the welding body wet

3. The construction site is equipped with two intact fire extinguishers, and the construction personnel are skilled in the use of fire extinguishers. At the same time, 0.2m3 of sand is stored in the operation site for standby

4. The person in charge of the construction and the welder must wear a portable gas alarm. When the gas concentration exceeds the limit, the operation must be stopped immediately, and the personnel must be evacuated to the air inlet of the working face. The operation can be continued only after the cause is found and handled

5. Switches and junction boxes of all equipment must use special mining explosion-proof equipment, and it is strictly prohibited to replace them with other equipment

II. Safety technical measures for the use of gas welding:

in principle, gas welding must be carried out in the air inlet roadway, which belongs to rock roadway or although it belongs to coal roadway, the top and bottom sides have been closed with non combustible materials. In addition, the following safety technical measures shall be implemented:

1. Before starting the work, the working face must be in the shutdown state; When working in the return air lane, it must be ensured that all the exhaust air discharged to the mining face of the return air lane is in the shutdown state. It is required that the workplace must be in a safe place, the roof scale and slope must be handled thoroughly, temporary support must be set when necessary, and the slope protection must be knocked out when working in the fully mechanized mining face. At the same time, a detailed inspection must be carried out according to the following requirements:

(1). The acetylene generator and its connecting parts must not leak

(2) the rubber hose should be free of bulges, cracks or air leakage. If there is air leakage, cut off the damaged part, use double-sided joint pipe, and tie it tightly with clamps or metal binding wires

(3) the welding gun connection must be tight, and if the mouth is blocked. Copper wire can be used to cut through, and iron wire is not allowed

(4) there must be no oil and mud on the accessories of the oxygen bottle mouth, the leather pad and the pressure reducer, otherwise it must be wiped clean

2. Relevant transportation safety measures shall be taken for the transportation of gas welding equipment. Oxygen cylinders and acetylene cylinders shall not be loaded, unloaded and transported in the same vehicle with grease, inflammables and explosives. They must be handled with care and bound firmly to prevent rolling. Oxygen cylinders and acetylene cylinders are not allowed to collide; Anti vibration rubber rings should be installed on the oxygen cylinder, and check whether the safety helmet is tightened before handling; It is strictly prohibited to put it near the heat source

3. When working, oxygen cylinders and acetylene cylinders should be placed vertically and properly fixed to prevent falling down

4. During the use of oxygen and acetylene cylinders, the distance between cylinders should be kept more than 10m. It is strictly forbidden to put oxygen and acetylene cylinders together

5. Before welding, sundries within 20 meters around the working place must be cleared. Two fire extinguishers and a 0.2m3 sandbox filled with sand must be prepared as emergency supplies. Welders shall have cooling water at the place where they work to cool the welding nozzle and cutting nozzle

6. When gas welders operate, they must wear special protective eyes, and protective work clothes and gloves cannot cut workpieces directly on the cement floor

7. In case of explosion due to overheating and blockage of welding nozzles and cutting nozzles, the acetylene valve should be quickly closed first, then the oxygen should be closed, and then put into cooling water for cooling

8. Before welding, the receiving device such as iron box, iron bucket or iron trough must be carried, and a suitable place must be selected to receive high-temperature sparks and fires. Researchers use carbon nanotubes to "bolt" each layer of composite materials in one piece. The receiving device must be able to receive all possible sparks and fires. At the same time, it is required that the receiving device must be pre placed with at least 100mm thick wet sand (hand grasp into a ball is the standard) or 100mm deep water

9. When welding and cutting guns are ignited, open the oxygen valve first, then the acetylene valve, ignite immediately, and then adjust the flame. On the contrary, close the acetylene valve first, and then the oxygen valve to avoid backfire

10. In case of flashback, close the acetylene valve immediately, and then close the oxygen valve. It is strictly forbidden to open the oxygen and acetylene valves at the same time. It is strictly forbidden to block the welding nozzle and cutting nozzle with hands or other objects to prevent oxygen from flowing back into the acetylene cylinder. Ignited welding tools and cutting tools cannot be placed on the work or ground at will

11. When igniting the welding nozzle and cutting nozzle, it is not allowed to use hot metal or put it on the hot workpiece

12. After welding, screw on the valve nut, pack up the tools and materials, keep them properly, and deal with the abnormal phenomena found in the work

13. After the completion of gas welding, clean the site and sprinkle water to extinguish the debris with sparks. The construction director and tile inspector must continue to observe, and confirm that the weldment is cooled within at least 60min, and there is no hot slag or fire point within 10m near the gas welding site. Only after confirming that there is no problem can they leave

14. The operation of gas welders shall strictly implement this safety technical measures

1 first, check whether the friction force of the working part is too large. 5 other matters shall be carried out in strict accordance with the relevant provisions of the coal mine safety regulations

16. After the completion of gas welding, relevant equipment and tools shall not be stored at the construction site, but must be recycled

III. other requirements

1. During the work at the welding site, the safety director, construction director, security inspector and tile inspector must conduct on-site command, supervision and inspection, have a clear division of labor, carefully implement safety technical measures, and prohibit miscellaneous personnel from staying at the construction site

2. All construction personnel should pay attention to the environmental changes of the construction site at any time, and immediately notify others and take measures in time if any danger is found:

3. During the welding process, the tile inspector must be seriously responsible and notify all construction personnel in time if any problem is found

4. Operators must receive professional training and work with certificates

5. Site operators must have certain fire safety knowledge and be skilled in using fire fighting equipment