Ammonia refrigeration pipeline open-flame-free plugging method
Technical Field
The invention belongs to the field of maintenance and repair methods of ammonia refrigeration pipelines, and relates to a maintenance and repair pipe clamp for tiny leakage points on pipelines of an ammonia refrigeration system of a refrigeration house in the food cold chain logistics industry or a plugging method for meeting the need of non-welding repair.
Background
The ammonia refrigerant is transported in the ammonia refrigerating system pipeline, which belongs to poisonous, inflammable and explosive working media, and according to the GB50072-2010 refrigerating design specification, the ammonia refrigerating pipeline pipe adopts a GB/T8163 seamless steel pipe, and the high pressure side design pressure of the ammonia refrigerating pressure pipeline is 2.0Mpa, and the low pressure side design pressure is 1.5Mpa. After the refrigerator is operated for a certain period of time, the conditions of sand holes, needle-shaped small holes and the like of the parent metal and the welding line of the individual ammonia refrigerating pipeline are often met. Accidents such as personnel poisoning or fire and explosion are easy to occur after the leakage point of the pipeline is enlarged.
At present, the conventional treatment generally needs to stop production and empty an ammonia refrigeration pipeline of a section to be maintained, and the leakage point can be subjected to welding and plugging on the premise of connecting the atmosphere; however, aiming at old systems with longer pipelines, oil is easy to accumulate in the pipe wall, the emptying time is long, so that the refrigerating system is stopped for a long time, and goods in a refrigeration house are easy to deteriorate; if the oil-ammonia mixture is not completely discharged, explosion accidents are easily caused when the oil-ammonia mixture meets open flame of electric welding.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides the open flame-free plugging method for the ammonia refrigeration pipeline, so that electric welding plugging is not needed when the ammonia refrigeration pipeline is in maintenance and repair, the risk of welding plugging accidents is avoided, and the maintenance time and cost are saved.
The technical scheme of the invention is as follows:
An ammonia refrigeration pipeline open-fire-free plugging method comprises the following steps:
step 1, when a tiny leakage point appears on a pipeline of an ammonia refrigeration system, and leakage stopping operation is needed, drilling and tapping are carried out on the leakage point, and internal threads are formed;
Step 2, screwing the leakage point plugging bolt and the leakage point plugging sealing gasket into the threads of the leakage point after the drilling and tapping in the step 1;
And 3, relatively matching and pressing the two semicircular pipe clamps on the upper part of the leakage point plugging bolt, and locking the two ends connected with the two semicircular pipe clamps through the bolt, the spring pad and the nut respectively to further press the leakage point plugging bolt so as to complete the leakage point plugging.
Preferably, step 1 performs a drill tap throughout the pipe wall thickness.
Preferably, the leakage point plugging bolts in the step 2 penetrate through the pipe wall after being screwed, but do not touch the pipe wall at the other side.
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, are arranged in threads drilled and tapped at the leakage point of the ammonia refrigeration pipeline, and are used for plugging the leakage point of the ammonia refrigeration pipeline. The whole plugging process is sealed by a plugging bolt and a plugging sealing gasket; because the method of bolts and fixed pipe clamps is adopted for plugging, the method has no influence on safety of a small amount of oil-ammonia mixture remained in the ammonia refrigeration pipeline, thus plugging operation can be carried out without nitrogen purging, replacement and welding, the explosion risk of open flame in welding plugging operation caused by incomplete evacuation of the oil-ammonia mixture in the ammonia refrigeration pipeline can be avoided, the maintenance and repair period can be shortened, and the cost can be saved.
Drawings
Fig. 1 is a schematic diagram of a plugging state of a preferred embodiment of an ammonia refrigeration pipeline non-open flame plugging method according to the present invention.
In the figure: 1, a semicircular arc pipe clamp; 2, a bolt; 3, a nut; 4, a spring pad; 5, plugging the bolts by the leakage points; 6, plugging a sealing gasket by a leakage point; and 7 ammonia refrigeration pipelines.
Detailed Description
Other advantages and features of the invention are illustrated by the following description of embodiments of the invention, given by way of example and not by way of limitation, in connection with the accompanying drawings, in which:
An ammonia refrigeration pipeline open-fire-free plugging method comprises the following steps:
step 1, when a tiny leakage point appears on a pipeline of an ammonia refrigeration system, and leakage stopping operation is needed, firstly, drilling and tapping the whole wall thickness of the pipeline at the leakage point, and forming internal threads;
step2, screwing the leakage point plugging bolt 5 and the leakage point plugging sealing gasket 6 into the threads of the leakage point after the drilling and tapping in the step 1; the leakage point plugging bolt 5 penetrates through the pipe wall after being screwed and does not touch the pipe wall at the other side;
and 3, relatively matched and pressed on the upper part of the leakage point plugging bolt 5 through the two semicircular pipe clamps 1, and locking the two ends connected with the two semicircular pipe clamps 1 through the bolt 2, the spring pad 4 and the nut 3 respectively, so as to further press the leakage point plugging bolt 5 and complete the plugging of the leakage point.
The semicircular pipe clamp is 2mm.
The leakage point plugging screw plug is made of carbon steel or stainless steel.
The leakage point sealing gasket is a tetrafluoro gasket.
Although the invention has been described in terms of the preferred embodiment, it is not intended to limit the scope of the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.