Brazing method of disc labyrinth valve cage assembly structure

Abstract

The invention discloses a method for brazing a butterfly-shaped labyrinth valve cage structure. Nano inorganic high temperature resistant coating, after curing, fill the flow channel with epoxy resin organic filler and / or paraffin filler, and smooth it to align with the butterfly substrate. After curing, apply nano inorganic high temperature resistant coating on epoxy resin Resin organic filler surface, and finally smear brazing material on the non-runner area of ​​the disc base to obtain a pre-sintered disc base; Step 2: Align the pre-sintered disc base prepared in Step 1 layer by layer and add them together , form a caged structure, tighten it with a fixture, and then sinter. By improving the above brazing process, the present invention reduces the sintering temperature, increases the bonding strength between the welded parts, and effectively prevents the flow passage opening from being blocked.

Description

technical field [0001] The invention belongs to the technical field of valves, and in particular relates to a brazing method for a disc-type labyrinth valve cage assembly structure. Background technique [0002] The multi-stage labyrinth pressure-relief valve adopts a labyrinth flow channel regulating valve composed of multi-layer discs. Through the position of the valve core and the disc assembly, the flow of the medium flowing through the valve is adjusted. Its frequent bending increases the resistance along the way, and greatly reduces the pressure of high-pressure gas or steam. Due to the effective multi-stage pressure reduction, the liquid will not produce cavitation, and the noise during the pressure reduction process is reduced. [0003] The labyrinth regulating valve is mainly composed of a plurality of discs, and there are many small flow channels arranged axially symmetrically on the surface of each disc. These flow channels diverge from the central hole in the rad...

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Problems solved by technology

[0006] At present, there are many problems in the cage structure made by the above-mentioned ordinary smearing and brazing process, which are described as follows: firstly, the paint applied on the disc will easily flow into the flow channel due to the siphon phenomenon during the high-temperature sintering process. Finally, part of the flow channel openings are blocked. If more than a certain number of flow channel openings are blocked or partially blocked, the product will be scrapped.

Another situation is that the brazing performance of the solder and the base material of the disc is not good, which causes the part of the welded area to be unreliable, or even completely disengaged.

Another situation is to increase the sintering temperature in order to enhance the reliable performance of welding. Because the process temperature is too high, in this case, during the vacuum sintering process, due to the many symmetrical flow channels in the middle of the butterfly, and the thin sheet shape of the butterfly itself Due to the influence of temperature, a large thermal stress is generated, and finally the surface of the butterfly is bent, so that the butterfly cannot be strictly sealed and the product is unqualified

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