Non-open-fire leakage blocking method for ammonia refrigeration pipeline
Technical Field
The invention belongs to the field of maintenance and emergency repair methods for ammonia refrigeration pipelines, and relates to a leakage stopping method for maintaining and emergency repairing pipe clamps of tiny leakage points on refrigeration house ammonia refrigeration system pipelines in the food cold chain logistics industry or meeting non-welding repair requirements.
Background
The ammonia refrigeration system pipeline internal conveying refrigerant ammonia belongs to toxic, inflammable and explosive working media, and according to GB50072-2010 refrigeration house design specifications, an ammonia refrigeration pipeline pipe adopts a GB/T8163 seamless steel pipe, and the design pressure of the high pressure side of an ammonia refrigeration pressure pipeline is 2.0Mpa, and the design pressure of the low pressure side of the ammonia refrigeration pressure pipeline is 1.5 Mpa. After a certain period of operation of the refrigeration house, the conditions of sand holes, needle-shaped small holes and the like of parent materials of individual ammonia refrigeration pipelines and welding lines are often met. After the leakage point of the pipeline is enlarged, accidents such as personnel poisoning or fire, explosion and the like are easy to happen.
At present, the conventional treatment generally needs to stop production and empty the ammonia refrigeration pipeline at a section to be maintained, and the leakage point can be welded and blocked under the premise of connecting the atmosphere; however, for an old system with a long pipeline, oil is easy to accumulate in the pipe wall, and the emptying time is long, so that the refrigerating system has long cold stopping time, and goods in a cold storage are easy to deteriorate; if the air is not completely discharged, the oil-ammonia mixture is exposed to electric welding naked flame, so that explosion accidents are easily caused.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide the method for stopping the leakage of the ammonia refrigeration pipeline without open fire, so that the leakage of the ammonia refrigeration pipeline is stopped without electric welding during maintenance and rush repair, the risk of welding leakage accidents is avoided, and the maintenance time and the maintenance cost are saved.
The technical scheme of the invention is as follows:
an ammonia refrigeration pipeline open fire-free leaking stoppage method comprises the following steps:
step 1, when a tiny leak point appears on an ammonia refrigeration system pipeline and leak stopping operation is needed, drilling and tapping are performed at the leak point, and internal threads are formed;
step 2, screwing a leakage point plugging bolt and a leakage point plugging sealing gasket into the thread at the leakage point after drilling and tapping in the step 1;
and 3, the two semi-circular pipe clamps are oppositely matched and tightly pressed on the upper part of the leak point plugging screw plug, two connected ends of the two semi-circular pipe clamps are respectively locked through bolts, spring pads and nuts, the leak point plugging bolt is further tightly pressed, and the leak point plugging is completed.
Preferably, step 1 is to drill and tap the entire pipe wall thickness.
Preferably, in the step 2, the leak plugging bolt penetrates through the pipe wall after being screwed tightly but does not touch the pipe wall on the other side.
The invention has the advantages that the leakage point plugging bolt and the leakage point plugging sealing gasket are directly arranged at the leakage point of the ammonia refrigeration pipeline of the food cold chain refrigerator, the leakage point plugging bolt and the leakage point plugging sealing gasket are arranged in the thread drilled and tapped at the leakage point of the ammonia refrigeration pipeline, and the leakage point of the ammonia refrigeration pipeline is plugged by the leakage point plugging bolt and the leakage point plugging sealing gasket. The whole leaking stoppage process is sealed by a leaking point plugging bolt and the leaking point plugging sealing gasket; because the method of bolts and fixed pipe clamps is adopted for plugging, the method has no influence on the safety of a small amount of oil-ammonia mixture remained in the ammonia refrigeration pipeline, so that the plugging operation can be carried out without nitrogen purging replacement and welding, the explosion risk of electric welding and welding plugging operation open fire due to incomplete emptying of the oil-ammonia mixture of the ammonia refrigeration pipeline can be avoided, the maintenance and first-aid repair period can be shortened, and the cost can be saved.
Drawings
Fig. 1 is a schematic view of a plugging state of a preferred embodiment of the method for plugging an ammonia refrigeration pipeline without open flame according to the invention.
In the figure: 1, semi-circular pipe clamp; 2, bolts; 3, a nut; 4, a spring cushion; 5, plugging bolts at leakage points; 6, sealing gaskets are sealed by leakage points; 7 ammonia refrigeration pipeline.
Detailed Description
Further advantages and features of the invention are illustrated by the following description of embodiments of the invention, given by way of example and not of limitation, with reference to the accompanying drawings, in which:
an ammonia refrigeration pipeline open fire-free leaking stoppage method comprises the following steps:
step 1, when a tiny leak point appears on an ammonia refrigeration system pipeline and leak stopping operation is needed, firstly, drilling and tapping are carried out on the wall thickness of the whole pipeline at the leak point, and internal threads are formed;
step 2, screwing a leakage point plugging bolt 5 and a leakage point plugging sealing gasket 6 into the thread at the leakage point after drilling and tapping in the step 1; the leak plugging bolt 5 penetrates through the pipe wall without touching the pipe wall on the other side after being screwed tightly;
and step 3, the two semi-circular pipe clamps 1 are oppositely matched and tightly pressed on the upper part of the leak source plugging screw plug 5, two connected ends of the two semi-circular pipe clamps 1 are respectively locked through the bolt 2, the spring pad 4 and the nut 3, the leak source plugging bolt 5 is further tightly pressed, and the leak source plugging is completed.
The semi-circular pipe clamp is 2 mm.
The leak source plugging screw plug is made of carbon steel or stainless steel.
The leak source plugging sealing gasket is a tetrafluoro gasket.
Although the present invention has been described in terms of the preferred embodiments, it is not intended that the scope of the invention be limited to the exact construction described above, and equivalent alternate constructions will occur to those skilled in the art upon reading the foregoing description and are intended to be encompassed by the present invention unless they depart from the spirit and scope of the invention.