I believe that those of you who have dealt with valves are not unfamiliar with the names of these butterfly valves. However, Dervos found that there are still many friends who can't tell the differences between a concentric butterfly valve and aWafer butterfly valve, and some may even think that they are different names fora same valve. But it's not. This article will introduce you to the difference between a concentric butterfly valve and aWafer butterfly valve.   Concentric butterfly valve isnamed after the structural form of the valve. In addition to concentric butterfly valve, there are also single eccentric butterfly valve, double eccentric butterfly valve, triple eccentric butterfly valve several.They are named conforming tothe position of the centre of the butterfly plate in the valve body.In terms of structure,the concentric butterfly valve is characterized by the stem axis, the butterfly plate centre and the body centre being in the same position.   The concentric butterfly valve has a simple structure, and usually soft-seated. Rubber or PTFE or other resilient materials are most common;The concentric butterfly valve has very good sealing performance, and can achieve zero leakage. But limited by the sealing material itself, the concentric butterfly valve can only beapplied to normal temperature and low pressure environment. Its not recommended to use them in high temperature and high pressure.   Wafer butterfly valve is named according to the butterfly valve's connection method. In addition toWafer, there are also flange connections,clamp connection,socket-ed,welded and so on. Wafer butterfly valves can be soft-sealed ormetallic-sealed; they can be ofconcentric or eccentric.A concentric butterfly valves may be either clamped or flanged. Aconcentric butterfly valve may be aWafer connection, and aWafer butterfly valve may also be ofconcentric construction.   Therefore, the concentric and Wafer are two different butterfly valve classifications, the two are actually not comparable. Choose the correct butterfly valve according to the different working conditions, and that’s all.   Dervos is a leading valve manufacturer and provider of engineered products for different industries in China. If you’re looking for professional feasible solutions, check out our vast range of high-quality valves which covers gate valves, ball valves, butterfly valves, as well as other control valves and more.   For more information regarding our high-quality products, contact us today!

Can butterfly valves be used for hot water? In previous articles, we have introduced to you that butterfly valves are suitable for fresh water, sewage, sea water, salt water, steam, natural gas, food, pharmaceuticals, oil and other pipelines that require complete sealing, zero leakage in gas tests, high life expectancy and working temperatures from -10 degrees to 150 degrees. Weather butterfly valve can be used in hot water pipeline or not, in fact, the key lies in the valve seat sealing surface material ofthe butterfly valve body that contacts with hot wate rdirectly. The hot water we talk about is generally water above 70℃.There will be no problem at all if you use hard seal butterfly valves at these temperatures. But if it is a soft seal butterfly valve with a rubber sealed seat, can it be used for hot water? If you search the internet for the answer, you will see that many do not recommend the use of soft seal butterfly valves in hot water. The reasonis thatthe rubber seat of a soft seal butterfly valve will age more rapidly if it is exposed to hot water for a long period of time. The sealing performance of the valve will be damaged, thus shortening the service life of the valve. This statement is not a problem, the theoretical temperature range of rubber material is -20 ~ 150℃,but because of the various manufacturers produce rubber quality levels, inreal situations, this temperature range willnarrow down significantly in the hot water environment, of course. However, the soft seal butterfly valve is not completely inadequate for hot water piping. High temperature resistant rubber can be used, which is much more effective and lasts longer. And hard-sealed butterfly valves, ball valves, gate valves and globe valves can also be used instead. Dervos is a leading valve manufacturer and provider of engineered products for different industries in China. If you’re looking for professional feasible solutions, check out our vast range of high-quality valves which covers gate valves, ball valves, butterfly valves, as well as other control valves and more. For more information regarding our high-quality products, contact us today!

The answer is definitely a NO!   In Structure, if space is limited   Gate valve relies on the medium pressure to tightly seal the surface, so as to achieve the effect of no leakage. When opening and closing, the disc and seat sealing surface are always in contact and rubbing each other,which leads to a worn sealing surface. When the gate valve is about to close, the pressure difference between the front and rear of the pipeline is very large, which also contribute to a more serious the sealing surface damage.   The structure of gate valve is more complex than that of globe valve. In terms of the shape gate valveis higher and more narrow than globe valve, assuming they are of same caliber. In addition, stem of gate valve falls into two categories, rising or non-rising, while globe valve’s stem does not. Working Principle Globe valves open and close with a rising stem, which means that when the handwheel is turned, the handwheel moves along with the stem up and down. As for gate valve, the handwheel is turned, stem move up and down, but handwheel itself stays at the same position.   Their flow rates vary. Gate valves have to be full opened or closed, while globe valves do not. Globe valves have a defined inlet and outlet direction, while gate valves do not.   In addition, the gate valve has only two states: fully open or fully closed,and the long travel of the disc results in a longer switching time.The time a globe vale needs is muchshorter. Most importantly, thedisc of the globe valve can stop at a certain place inthe valve body to do flow regulation. The gate valve can only be used for cut-off and has nosuch function. Performance differences Globe valves can be used for both cut-off and flow regulation. The fluid resistance of globe valve is relatively high, and it takes more effort to open and close, but because the distance between the valve plate and the sealing surface is short, the opening and closing stroke is short.   When gate valve is fully open, the medium flow resistance in the valve body channel is almost 0, so the gate valve opening and closingwon’t be very laborious. But the gate plate is far from the sealing surface, opening and closing time is longer.   Xiamen Dervos is an API Certified check valve manufacturing and trading company that specializes in the production of various kinds of valve. In addition to all kinds of common valves such as gate valves, globe valves, plug valves and butterfly valve , we also produce otherunconventional valves as long as our customers file their requirements.To learn more about our industry-leading products, contact us today.

Transfer line valves and decoking valves, or TLV & DV for short, are essential in ethylene pyrolysis, and their performance have a marked impact on the operation and safety of the process. First of all, here comes our Transfer Line Valves (TLV) & Decoking Valves (DV) features: DN differing from 3 to 54 inch, Our transfer line valves & decoking valves can work with almost all types of ethylene pyrolyzer, including CBL(SEI), BYC(Wison), SRT(Lummus), USC(S&W), Pyrocrack(Linde), SC-II(KRB) and other popular types in the market. Transfer Line Valves and decoking valves operate in very demanding service handling high temperature, fouling conditions, high tightness requirements, high reliability requirements and they are critical from a safety point of view.  Thus,we care product design and selection. The main focus lay on the following properties: Firstly, we focus on anti-coking performance, especially in the opening position and switching process; Secondly, particle resistance, which primarily refers to the sealing surface being prevented from being covered by particles. It reduces pressure loss, so as not to lead to seal failure or hampered operation; And finally, we pay extra attention to valve sustainable service and easy maintenance. We are an outstanding player in the valve industry for more than a decade. Located in China, we manufacture valves on our own, at the same time, we cooperate with an array of excellent valve suppliers to meet your various kinds of demands. If you have any needs of or interests in these two kinds of special valves, welcome to contact us for more product information. Or if there is anything we can help with, we shall be more than pleased to do so.

We often regard 2 inch as the dividing line to decide forging or casting of valves. Unlike other valves, the manufacturing method of ball valve is not subject to valve size. Even for big size ball valves, we will use forging way sometimes. Compared to cast steel ball valves, forged steel ball valves can bear more strength and more serviceable. The quality of original material forging is of better quality with less defectiveness. For high pressure working condition, we'd better choose forged steel ball valves. Cast ball valves come with less weight and lower cost than forged one. Xiamen Dervos is an API Certified check valve manufacturing and trading company that specializes in the production of various kinds of valve. In addition to ball valve, we also produce other industrial pipeline valves, such as gate valves, globe valves, plug valves and butterfly valve. To learn more about our industry-leading products, contact us today.

As a component in the pipeline, valves control the connection and cut-off of the fluid. Valve is like a brake pad on the car, one broke, it may lead to unexpected consequences.  Therefore, the valve's performance and service life directly affect the operation of the system. If the valve is damaged, the system must be shut down for maintenance, the losses which brings immensely outweigh the cost of such a few valves. The quality and life of the valve are so important. The bellows sealed globe valve is particularly outstanding in both aspects. Its double seal guarantees zero leakage but also reaches zero leakage in the helium mass spectrometry test. Very safe and reliable. The bellows can be cycled more than 10,000 times without damage, greatly exceeding the service life of an ordinary globe valve packing seal. In addition, the bellows sealed valve can prevent external dust from entering the valve body to ensure the cleanliness of the medium. In conditions such as high-purity silicon powder, pure oxygen, food, vacuum and other working conditions, the bellows globe valves still have a very outstanding performance. In the process of switching, common globe valves will see dynamic friction between packing and stem, and the packing will be worn and fail.  When globe valves are in high and low-temperature occasions, their packing will expand or contract, packing changes, resulting in packing seal failure; As for low-temperature conditions, the packing is easy to freeze,  the packing is easy to be scratched by ice in the witching process. In short, the advantages of the bellows globe valve compared with the ordinary globe valve can be summarized as follows. 1. The bellows globe valve can meet the request of zero external leakage in helium mass spectrometry. 2. The service life of the bellows sealed globe valve is much higher than that of the common globe valve, whose packing is susceptible and replacement frequency is higher. 3. The bellows sealed globe valve has a metal barrier at the stem seal, which can be used in working conditions where absolute isolation is required inside and outside the valve. 4. The bellows of the bellows sealed globe valve can expand and contract, which is not affected by thermal expansion and contraction, and it has very obvious advantages in the occasion of large temperature differences. 5. The bellows valve has double sealing. the bellows instinct, the packing is completely isolated from the medium, which protects the packing well and greatly extends the service life. Dervos is a leading valve manufacturer and provider of engineered products for different industries. If you’re looking for feasible solutions, check out our vast range of high-quality valves which includes gate valves, ball valves, butterfly valves, as well as other control valves and more. For more information regarding our high-quality products, contact us today.