The difference between center type butterfly valve and double eccentric butterfly valve
Dec 23,2021 Posted by Bundor
What is the difference between a central butterfly valve and a double eccentric butterfly valve? Bundor valve will introduce you.
Butterfly valves can be divided into central butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves, and triple eccentric butterfly valves according to their different structures. Among these types of butterfly valves, the central butterfly valve and the double eccentric butterfly valve are common soft-seal butterfly valves, which are used in low-pressure, normal-temperature pipeline environments. So what is the difference between a central butterfly valve and a double eccentric butterfly valve? Bundor valve will introduce you.
Center butterfly valve, also called centerline butterfly valve, its structural feature is: the center of the butterfly plate, the center of the valve shaft and the center of the valve body channel are in the same position. When the valve is opened and closed, there will be scratches between the rotation of the butterfly plate and the valve seat. Phenomenon occurs. The advantage of the center type butterfly valve is that the butterfly plate and the soft-seal valve seat are squeezed, the sealing performance is very good, and the leakage is 0. But this type of butterfly valve also has disadvantages. The first is the scratching phenomenon mentioned above, which will shorten the service life of the valve seat; the second is that the soft-seal valve seat is not resistant to high temperature and high pressure.
Center-type butterfly valves are mostly used in water supply and drainage pipelines, and the medium used is mostly clean water, steam, etc.
Double eccentric butterfly valve, a high-performance butterfly valve, double eccentric, as the name implies, the center of the valve shaft has two deviations, which deviates from the center of the butterfly plate and the center of the valve body channel. The advantage of this structural design is that when the valve is opened, the butterfly plate can be quickly separated from the valve seat, and the scratch phenomenon between the valve seat and the valve seat is also greatly eliminated, which reduces the resistance when the valve is opened, reduces wear and improves The service life of the valve seat is improved. But because there is no scratching, it means that the squeezing between the butterfly plate and the valve seat is also reduced, which makes the sealing performance of the valve not guaranteed, and there will be a certain amount of leakage.
Double eccentric butterfly valves are more widely used, such as water supply and drainage, sewage, construction, petroleum, chemical, textile, paper, hydropower, metallurgy, energy and other fields.