Pipe sealing technology is a kind of safe, economical, fast and efficient special technology for maintenance of pipeline in service. It can be in uninterrupted pipeline medium transport under the condition of complete replacement of pipeline displacement, change valve and increase regional operations, can also be in the pipeline leakage accidents in pipeline quickly and safely to repair, restore the pipeline operation.
Our country pipeline pipeline plugging business based on foreign technology, through scientific research, the number of independent innovation technology, plugging equipment improvement, sealing ability, specifications, types of business continues to improve, expanding, sealing diameter from 25 mm to 1020 mm of diameter, the sealing pressure up to 10 mpa.
The constant pressure belt pressure sealing technology is safe, reliable and free of pollution. It can not only affect the normal transportation of pipelines, but also ensure the safety, efficiency and environmental protection of the connection between old and new pipelines. Don't stop plugging technology for medium oil, natural gas, water, gas, oil, ethylene, fuel and other non corrosive medium.
(1) excavation and plugging operation pit;
The excavation pit plugging operation, by the construction team unified command excavators, other personnel away from the scene, such as wounding, immediately launched the emergency plan; to avoid plugging pit landslides, the pit surrounding must have a certain slope. If a landslide occurs, the organization should be organized immediately.
(2) welding with pressure to seal three pass
Before welding according to the pipe material, operation parameters and welding material for welding process instruction, according to the welding process instruction after welding welding technology evalsuation, according to the qualified welding welding procedure qualification of welding procedure. Welding shall be carried out according to welding procedures; welders shall be provided with protective equipment to avoid arcing injury; if any injuries occur, they should be sent to hospital immediately. If the phenomenon of welding through, should immediately plug with welding electrodes, and welding dead, such as the emergence of fire, should immediately open emergency response program.
(3) airtight opening;
In case of oil leakage in case of opening, immediate action shall be taken to find out the oil spill point and remove it. If there is a fire, emergency measures should be activated immediately. If the cutting tool, should immediately pull valve, stop the analysis of the causes, restart; if the tool is damaged, should be decisive about cutter, close the valve tool for standby splint.
(4) plugging
When plugging, we should follow the principle of "first high pressure, then low pressure, first inner side and lateral side", that is, first sealing the high pressure end and then sealing the low voltage end. When the lower plug, the valve on the plywood valve closed or lax, resulting in oil spills or fire, immediately start the emergency program at this time.
(5) pumping oil;
Oil discharge should be carried out after plugging successfully. Drain point shall be as far as possible at the bottom of pipeline, and intake point shall be at the top of pipe line as far as possible. If there is oil leakage or fire phenomenon, start the emergency program immediately.
Before pumping, it is necessary to ensure that the insulation layer of the power line is not damaged, and that the oil pump ground is good. If there is an electric shock, start the emergency program immediately.
(6) cut pipe;
Bundled tube cutting machine before, first check the track, is bound to check the motor reversing, to ensure that the chain in a straight line, and be tied tightly to prevent walking pipe cutting machine.
When cutting the pipe, the switch should not be damaged before the power is turned on and the power line is connected well. If there is an electric shock, start the emergency program immediately.
(7) build a grease wall
The construction of a grease wall is performed after the completion of the cutting pipe or the suspension of the old pipe or equipment. First, clean up the dirty oil on the inner and outer walls of the pipe, and use explosion proof tools when cleaning. If there is an explosion, start the emergency response immediately.
(8) pipe collision;
When the pipeline is facing and welding, it is strictly forbidden to knock the vibration pipeline; the construction should be rapid; the shorter the better; if the ambient temperature is too hot, it is necessary to take measures to cool down the pipeline at the wall of the grease.
Because when the counterpart knocks pipelines, the construction time is too long, the weather is too hot, it may lead to cracks in butter wall on the upper part, even butter tube wall, oil and gas overflow, when electric ignition, easy to cause the explosion, at this time should immediately start the emergency plan.
(9) lifting the plug;
Lift the closure must be finished in the pipeline construction, in principle, to lift the low end, the lifting of the high end, equipment removal, to check whether the bypass valve plate closed, and then from the oil discharge outlet of nitrogen into the oil, after the removal of equipment again. If there is no nitrogen, there will be oil flow or serious fire, at this time should start the emergency program immediately.