Q: Hi. I saw the butterfly valves in your website. Some of them is equipped with a handle,some a gearbox, and they all look to be about the same size. Are the two types of operation equivalent? When You Should Apply Gearbox To Butterfly Valve? A:Gearbox butterfly valves and handle butterfly valves are both butterfly valves that require manual operation, so both of them can also be referred to as manual butterfly valves. For small butterfly valves, the two types of operation can be common. The difference lies in the large-diameter butterfly valves. Specifically,manual operation is suitable for butterfly valves with a calibre ≤ DN200; And butterfly valves within DN200 can also be operated with agearbox. For butterfly valves of DN200 ormore,Gearbox operation is generally recommended. The reason is that as the calibre of the butterfly valve increases,  so does the torque. When the calibre exceeds DN200, it will be very hard to operate with the handle, and the larger the calibre, the harder it will be to operated by a handle. Therefore, if the caliber is DN200 or more, it is better to use a gearbox. When Dervos chellenged to manufacture a butterfly valve of DN3750, we used 4 gearbox to drive the gaint guy. For more details welcome to click the picture to read the story. 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!

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.

How time flies! Dervos had another challenging but fruitful year and is ready to step into its 13th year in the valve market. It’s time to celebrate its birthday.   As usual, we spared a day for this big event of Dervos. The day, we call it the happy day, is comprised of a quite lot of activities. We rented a big house where there are a hoard of miscellaneous recreational facilities, for instance, karaoke, private cinema, AR game and so on. What’s more, its spacious kitchen and dining area are also in favor of our first activity--group cooking!   The presumed ticklish part--you know, the participants are a group of urban white-collar workers who are fed by all the food delivery apps, what more do you expect from them?-- turned out to be more than amazing: Fish Filets in Hot Chili Oil, Meat Ball, Mushroom Stew and the impressive Sea Food Pot delivered by Eric, founder of Dervos.   Speaking of the founder, the other one Ken brought a delicate cake shaped into the number 13, beautiful and palatable. Plus the exquisite dessert, the meal of that noon really set a wonderful beginning of the happy day. Then we move to the recreational area. If you see someone screaming BACK OFF! STAY AWAY FROM ME! wielding gamepad, shooting monsters on screen, don’t worry, that’s just Jona playing AR games. She’s probably going to win the most dedicated player prize if there were any.   One more game I’d like to note is ring toss. The ring needs to circle the bottle and win you the gift coupon beneath it. I know it’s kinda old-stuff, but when you attend another game to win extra chances for ring toss if you don’t gain anything at first round, it would be more fun. The gamer needs to spin 5 circles and flip a bottle cap about 2 meters away at once, with one eye covered all the time. It was crazy dizzy, difficult and fun, cause you could never hit it accurately after 5 circles as you thought the cap was there but it was actually not. In the evening, after a string of group games like Guess the song name and Charade, the climax of the day came as the projection screen started playing a surprising video for West, also the game host, whose journey with Dervos has rang the 10-year bell and hasn’t anticipated for this part. After the video, Eric and Ken, on behalf of the big family, awarded him a secret anniversary gift.   Now, let’s call it a day, or it would be better to be ‘let call it 13 years’.   If Dervos were a 13-year-old boy, it is when the boy explores the world curiously and energetically. It is like a rising sun from the skyline, we’ll see his sun ray, glory and feel his warmth. Dervosers are striving for this day.