With the continuous development of domestic industry, used on pipeline insulation ball valve demand also will increase, more and more is also high to the requirement of insulation ball valve, the user selects the insulation ball valve, did pay special attention to the valve has good sealing performance to prevent the leakage of the medium.
Due to import insulation ball valve has good reliability, so the user of the more important parts of the imported thermal insulation ball valve, but import insulation ball valve is expensive, delivery cycle is long, after-sales service is not convenient, seriously affect the operation of the whole pipeline.
In order to reduce the cost of pipeline insulation ball valve, realize localization, domestic manufacturer has on the quality of the domestic insulation ball valve, sealing reliability strives for perfection, strive to replace the imported thermal insulation ball valve.
In this paper, aiming at insulation ball valve on the question of high temperature resistant were analyzed and improvement measures are put forward.
One, some questions existing in the field of thermal insulation ball valve is also called the jacket ball valve, is on the basis of the ball valve welding metal jacket, jacket and the valve body between thermal channel, channel and injecting steam or other heat medium, to ensure that the media can work normally in the valve.
Insulation ball valve with good insulation properties, and the valve and pipe diameter, and can effectively reduce the pipeline heat loss in the media.
Is mainly used in petroleum, chemical, metallurgical, pharmaceutical, food and other kinds of systems, in order to transport under normal temperature solidification of high viscosity medium.
Due to the valve seal structure and its corresponding sealing material, its use is less than the temperature of 200 ℃.
And for a long time at 200 ℃ under the condition of use, live shorter lives.
Although seat can choose short time ability 300 ℃ high strength graphite materials, but there are many need to seal in the valve parts still cannot seal in high temperature situation, especially in the radial sealing, high strength graphite materials not suitable for radial seal.
Usually radial sealing insulation ball valve is to use o-ring sealing structure, so use temperature of the valve directly restricted by o-ring used temperature, the thermal insulation ball valve on the use of o-ring is fluorine rubber, and the use of fluorine rubber temperature within 200 ℃, and cannot be used within the limit temperature for a long time.
Far cannot satisfy the requirement of market in many media, such as the working medium of rosin, it demands the use of thermal insulation ball valve temperature is 300 ℃, such ability is helpful for medium to obtain ideal liquid rosin, using o-ring as traditional sealing parts, will not be able to meet their requirements.
Second, the improvement measures according to the problems existing in the insulation ball valve, determine to improve the insulation ball valve sealing material and structure.
In a sealed cavity with high temperature resistant material of flexible graphite seal ring, at the back of the sealing ring with a taper section of the gasket, washer fitted behind the special structure of the screw, so by tightening the plug, plug will be passed to the gasket, washer cone section will squeeze the sealing ring, sealing ring deformation, make its tiejin, both inside and outside the radial bearing ring and body, so that insulation ball valve in the radial sealing structure of high temperature resistant, at the same time, by tightening the screw, produce pre tight seal between the sphere and valve seat, make its seal.
Also make corresponding improvement on the seat sealing structure, the insert structure, and the body bearing ring grooves dug up, groove bottom in sealed superior performance and high temperature resistance of the flexible graphite, can play a role at the bottom of the seat seal, and can play between the sealing deputy for heat bilges cold shrink compensation effect.
In flexible graphite is mounted on the high temperature resistant metal seated, use long time use within temperature to 425 ℃ can be improved, so as to solve the thermal insulation ball valve cannot be used at 200 ℃ or more long time.
And still can choose different material according to the requirement of the actual working condition of the seats.
Drainage role at the bottom of the pipe with plug is threaded connection, when the temperature rises, the threaded portion of seal is hard to guarantee, decided to cancel the plug, in figure 2 plug, which is connected with the bottom over changed into terraced drain plug and end connection with winding gasket sealing, to ensure that the seal at the bottom of the reliability.
By improving the thermal insulation ball valve sealing structure, good sealing performance, especially the improved flexible graphite instead of the o-ring, the temperature & le;
Is widely used on the working condition of 425 ℃.
With the development of domestic industrial level and technological progress, its performance will continue to improve, application scope will continue to expand.
Insulation ball valve is according to the market demand and improve the design and manufacture, the valve has a compact structure, convenient operation, reliable sealing and long service life etc, at present the insulation ball valve in the user running in good working condition, various performance indexes meet the design requirements.
For easy setting, high viscosity liquid medium with excellent performance, especially suitable for thick mass media such as rosin.