Characteristics and application of triple eccentric butterfly valve

Since its appearance, in order to meet the increasingly severe working conditions, the three eccentric disc valve itself has also experienced the process of self-improvement and continuous development Even though the basic zero leakage and three eccentric disc valves of Zui can be achieved in theory, they actually depend on careful design and precise manufacturing On the basis of absorbing and summarizing the advantages and disadvantages of other brands of triple eccentric disc valve, we have launched our own unique triple eccentric disc valve Tritec, which has the following characteristics: 1 API specifications are well known, and API609 has actually become the international specifications of industrial important pipeline valves And Tritec is designed and manufactured in strict accordance with the new 1997 edition of Zui in API 609 What's more, the basic design of Tritec is not limited to API specification, bs5155 ANSI B 16.34, ASME sec VIII and other specifications, which ensures that Tritec can be used in all industrial fields 2 The double safety structure Tritec is in strict accordance with the specification requirements of API609 In order to prevent the butterfly plate deformation caused by the influence of fluid pressure and temperature, the valve rod dislocation, sealing surface engagement, two independent thrust rings are respectively installed on the upper and lower sides of the butterfly plate, so as to ensure the normal operation of the valve under any working conditions; At the same time, in order to prevent sudden accidents caused by stem damage and flying out caused by unknown reasons, independent stem flying out prevention mechanism is designed at the inner and outer parts of the lower end of the valve, which also ensures that the pressure level of Tritec can reach 2500 pounds from the side 3 Dead zone free design Tritec In the design process, the application problems in the field of regulation and control are specially considered, the sealing principle of three eccentric butterfly valve is fully utilized, so that when the valve is opened and closed, the butterfly plate does not scratch the valve seat, and the torque of the valve rod is directly transmitted to the sealing surface through the butterfly plate, that is to say, there is almost no friction between the butterfly plate and the valve seat, thus eliminating the common jumping phenomenon of opening the ordinary valve and eradicating it In the low opening range of the valve, the regulation failure caused by various unstable factors, such as friction, means that Tritec can enter the adjustable region from 0 to 90, its normal regulation ratio is more than twice that of the general butterfly valve, and its regulation ratio is as high as 100:1 This creates a good condition for Tritec to be used as a control valve, especially when it is large diameter, the cost of the stop valve is extremely high, in addition, the stop valve cannot achieve zero leakage, in the case of emergency shut-off, it is necessary to install a shut-off valve on the side of the stop valve, while Tritec integrates control and shut-off, and its economic benefits are extremely considerable 4 There are two kinds of valve seat installation structures of the three eccentric butterfly valve Most of them are installed on the butterfly plate for the convenience of drawing, but Tritec adopts the body seat structure to install the valve seat on the body The utility model has the advantages that compared with the butterfly valve seat, the opportunity for the valve seat to contact the medium directly is greatly reduced, the degree of erosion of the valve seat is reduced, and the service life of the valve seat is prolonged 5 Thin layer valve seat structure Tritec The valve seat is made of stainless steel sheet and graphite sheet This kind of structure can effectively prevent the influence of small solid in the medium and the sealing surface occlusion caused by thermal expansion Even if there is small damage, there will be no leakage, which is unimaginable for the double eccentric butterfly valve or other three eccentric butterfly valve 6 Replaceable sealing pair Tritec When the sealing surface of the butterfly plate is damaged, there is no need to send it back to the manufacturer or break down the valve in a large scale It only needs to change the sealing surface of the butterfly plate This not only greatly reduces the maintenance cost, but also greatly reduces the maintenance cost The maintenance man hour, maintenance intensity and difficulty are also discussed 7 The balanced fixing structure starts from the shape characteristics of the sealing surface of the three eccentric butterfly valve The bolt ellipse distribution is adopted to fix the sealing pair of Tritec, which not only positions, but also equalizes the stress on each bolt, and eliminates the loosening and leakage of the sealing pair caused by the uneven stress distribution 8 Many valves of intrinsic fire-resistant structure claim to have fire-resistant structure, but most of them adopt soft and hard double seat structure in order to reduce leakage, which is actually very dangerous Because the incomplete combustion of soft seal valve seat in fire will cause stress and temperature difference deformation of metal support valve seat, which will lead to failure of fire engine Therefore, at present, Europe and the United States are gradually eliminating this kind of substandard refractory valve Tritrc, because of its zero leakage, does not need the assistance of soft seal, is a true fire-resistant structure, and has obtained the fire-resistant inspection certificate of api607, api6fa and bs6755part2 This ensures that Tritec can be used in oil, petrochemical and other dangerous areas A good example of Zui is the use of valves in the conservative UK and in key parts of its North Sea fields, almost all of which are covered by Tritec.