First, the general description:
In the aseptic production process, the most commonly used shut-off valve is a diaphragm type shut-off valve, often referred to simply as a diaphragm valve. The reason why the diaphragm valve is used in the aseptic production process is because of its simple structure and the low price, which makes it almost no "competitor" so far. The only thing that can compete with diaphragm valves is the so-called bellows shut-off valve, commonly known as the bellows valve. Because of its high price, this bellows shut-off valve is difficult to compete with the diaphragm valve despite its better technical advantage than the diaphragm valve. In this paper, by comparing the diaphragm valve with the bellows valve, the advantages and disadvantages of the two valves are more obvious.
Second, compared with the diaphragm valve, the advantages of the Vesta bellows valve:
"Competition between bellows and diaphragm valves" has a long history in the aseptic process industry. For a long time, diaphragm valves have taken advantage of their simple structure, low cost and convenient cleaning and disinfection. Compared to diaphragm valves, bellows valves are too few in the market. But today, the Vesta bellows valve produced by uchenhagen is filling this gap.
(1) The performance of the Vesta bellows valve is superior in the following aspects:
1. Emptying performance (1) When using a diaphragm valve in a horizontal pipeline, it must be ensured that the diaphragm valve is installed in the horizontal pipeline according to the angle specified by the diaphragm valve manufacturer. Otherwise, the diaphragm valve will be cleared during the operation of the process equipment. To some problems, the medium in the valve body cannot be completely discharged. However, the different diaphragm valve types, diaphragm valves produced by different manufacturers, and diaphragm valves of different nominal flow rates have different installation inclination angles, and often cause great troubles for the design and manufacture of aseptic process equipment. In the T-shaped diaphragm valve, the problem of emptying the valve body is more apparent. Compared with the diaphragm valve, the Vesta bellows valve does not have such a problem. No matter what kind of structure the valve body of the Vesta bellows valve is, there will be no “dead angle†when the process equipment is running at no load, thus ensuring strictness. Ground the pipe. Moreover, it can be installed in the piping system of aseptic process equipment according to different installation methods. 2. In the pharmaceutical manufacturing industry, aseptic process equipment consists of many horizontal pipes and vertical pipes. In the design of pharmaceutical equipment, such bellows valves must be installed and used at specific locations due to pipeline location and technical reasons. For example, if a diaphragm valve is installed in a vertical pipe, it must be connected via a 90° elbow in the same horizontal plane. The T-shaped diaphragm valve has a high production cost. Compared with the diaphragm valve with different valve body structure, the bellows valve has advantages in connection with the installation of the pipe in terms of volume and shape. Due to the different types of structure of the two types of shut-off valves, in the initial stage of the design of aseptic process equipment, it should be selected which type of shut-off valve should be used in each part. 3. Output devices in the fields of medicine, food and biotechnology have a large number of valves that require disinfection. Large valves, such as the Stericom series, have little use in this situation where disinfection is required. Because, in these process equipment, the amount of medium required to be transported is becoming less and less, and for less flow, the diaphragm valve is almost invariably selected. The new bellows valve has a smaller volume and can be used with different pipe diameters, which is superior to diaphragm valves in this respect.
2. The key component of the core component Vesta bellows valve is the cut-off bellows made of TFM1705 PTFE. In addition to its resistance to corrosion by various chemical media, TFM1705 material also meets FDA Federal Regulation 21 §177.1550 on “Perfluoro Carbonized resin" requirements. Its smooth surface (Ra ≤ 0.8mm), reliable sealing, large switching distance and other characteristics are very beneficial for the best CIP / SIP disinfection cleaning. For more than three years, this patented bellows valve has successfully established itself on the market and can strictly isolate the inside of the pipeline from the atmospheric environment outside the pipeline in aseptic process piping.
3. Comparison of equipment utilization
As a user of the device, the device is used for production as much as possible throughout the life of the device, that is to say: the utilization rate of the device should be as high as possible. The maintenance of the equipment means that the equipment must be stopped, and a certain amount of equipment maintenance costs must be invested. Bellows valves generally have wear phenomena; in diaphragm valves, once the valve wears out, the diaphragm must be replaced after a certain period of use. The service life of the diaphragm depends on the corresponding production process. On the one hand, the corrosion of the circulating medium in the process equipment, the temperature during pipeline cleaning and disinfection, the working pressure of the process equipment and the flow parameters will affect the service life of the diaphragm; on the other hand, the deformation of the diaphragm when the diaphragm type shut-off valve is opened and closed It is also an important factor in determining the service life of the diaphragm. The damage to most diaphragm valves is not due to the use in the production process, but rather to damage due to mechanical squeezing. Although diaphragms of diaphragm valves have different degrees of elasticity, different coatings, and different PTFE guards, all diaphragm valves have invisible wear from the outside (surface corrosion and particle adhesion caused by internal media) . Therefore, in order to prevent the aseptic process from being interrupted due to damage to the diaphragm valve, it is common practice to replace the diaphragm before the specified service life. In this way, whether it is the number of forced replacement diaphragms, or the resulting maintenance costs, or the downtime of the equipment, there are obviously more than the PTFE bellows valve, so the bellows valve has good performance and long service life. Another advantage of the Vesta bellows globe valve with pneumatic drive is that it can be used in almost any process.