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  • Ring Out 2020 & Ring In 2021
    Ring Out 2020 & Ring In 2021 Jan 05, 2020
    Time keeps moving forward, and we get the last day of 2020. As you may have seen, there are a lot of red elements in the following pictures. In Chinese culture, red stands for fortune and luck. We at Dervos all dress in red this day, wishing 2021 would be a red new year for us. It happened to be a Friday, and we finished work early in the afternoon and started to clean our respective work areas. It is kind of a traditional activity in China, sweeping out the old things and welcoming the coming year with a new look. Posting window decalsis also an indispensable work. Helena, the girl in the right pic below, was finishing the phrase that pretty much says new year new luck. Another girl was showing her amazing handcraft job. Count down 3, 2, 1. Finally we get through the terrible 2020 and step into a brand new 2021. Human society artificially divides time into days, months and years. That demonstrates our wishes to left the bad in the past and embrace the unknown future by the alternation of the old and the the new. Although 2020 is a bumpy year, Dervos maintains a positive mindset for the following 2021 and wishes our customers, in the new year, endless luck and joys.
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  • Special Cleaning Requirements for Cryogenic Valves
    Special Cleaning Requirements for Cryogenic Valves Dec 30, 2020
    Cryogenic valves are intended for very cold applications. The term "cryogenic" refers to temperatures below -50゜C.   Valve materials for cryogenic service are required for good ductility. Sealing parts, gaskets and other fittings should also be adapted to these extremely cold conditions on demand.   Industries associated with liquefied and compressed natural gas, as well as liquid oxygen, nitrogen or helium, rely on these special valves for the frequent, safe and reliable transport of cryogenic liquids and gases.   Special Cleaning Needs & Concerns To Be Stressed   The valve manufacturers are required to remove grease and all organic contaminants from the valve with a special solvent, keeping the valve clean. Ultrasonic cleaning is a common choice.   Some cleaning gases such as oxygen or chlorine require a very high level of cleanliness to ensure that no organic material or fiber breaks remain on the valve after the cleaning. The cleaned and certified valves are placed in double-sealed polyethylene bags to ensure that the valves are stored in a clean environment until they are installed and used.   Operators should perform a thorough inspection when installing cryogenic valves. This is critical to ensure that no lubricants or grease are accidentally introduced into the valve. Some specialty lubricants are available for use in cryogenic environments, and whether or not they are allowed should depend on the specific application requirements.   As mentioned earlier, cryogenic valves must avoid staining with fiber breaks. As a general rule, fibers longer than 1/8 inch are not allowed in the valve. In many cases, fibers or breaks of any length are not allowed in the valve.   Finally, inspectors should regularly check cryogenic valves and oxygen systems to see if there are internal or external leaks. Internal valve leaks can be prevented by installing the valve properly and a reliable seal design. Cryogenic service requires robust and stable seals to ensure long-lasting and reliable operation of the equipment. Here at Dervos, we’re a leading provider for products inindustrial valve, and we’re certified with the CE, ISO, API and other institutions. We strive to offer the best quality products and customer service through our extensive experience. Contact us today for more information.
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    The biggest valve Dervos has made ever. This is a DN3750 butterfly valve Dervos made forBombay Municipal Corporation in 2017 which is a government project. The project is special and challenging for its operation for suchalarge size of DN3750. As its torque isup to 989954N.m,it isbetter to be automatically actuated instead of manual operation. But as where it was going to serve is outreach of electrical power, manual operation is the only choice we have. After accurate calculation of the torque, finally we came up with a solution that DN3750 would be operated by a combination of total four gearboxes,which reduced theinput torqueinto incredible117N.m. What an amazing job we did! Andfor this valve, many tests had been carried out, including but not limited to below: We had done DP to the seat ring, UT to flanges, disc and stem, and RT to the welding. Besides, we had done strength tests to disc, adhesive tests to the painting, and IP68 Submergence Test by merging the gearboxes into 3-metre deep water by 72hours. And movement tests were also witnessed, it took about 9 hours from fully open to fully close position. Eventually,The completed valve was made out as about 58 tons weight and 82.4 CBM. Besides the remarkable work we did, we're so proud that its successful put-in-use was even reported by the local newspaper in Mumbai. As you can conclude, Dervos is indeed a professional and reliable valve provider. Contact us today, and get you the quality products and outstanding services Dervos offers.
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  • Dervos Team Building --This Time We Go Brisk Walking
    Dervos Team Building --This Time We Go Brisk Walking Dec 15, 2020
    It was on 11th of December, a rare cloudless afternoon in these consecutive chilly and dreary winterdays. "Now that the weather favoredus, it would be a huge waste to stay at the office, wouldn't it?" Eric Wong, DVS owner, suggested. Then, unexpectedly, we stopped typing, packed staff and went on the way to an extra long footpath that nearly cross the entire downtown. You may see from the image, the walkway spirals up into the woods along the steel frame. As we climb higher, it's getting challenging and scary to walk on the floating way, but the beautiful coastline also emerges on the horizon. As we Chinese always say attracting scenery is always higher. But unfortunately we are within a no-fly area, ourdroneis forbidden to liftoff,thelaugh on the first photo below turned into scowl off the camera. Quite hilarious! As the sun went down the hill, the 3-hour brisk walk finally came to an end till the dawn. The glistening sweaton our brow recorded this an joyful afternoon. Though we didn't finish the whole footpath (because it's way too long), we may regard this end asbeing archived, and some day in the future, perhaps we will have another chance to continue this unfinished trip. 2020 is also approaching an end. Don't forget to say goodbye to this unforgettable year and say hello to the coming unknown 2021. And, definitely, Dervos will be there for you.
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  •  Installation and Maintenance of Pneumatic Butterfly Valve
    Installation and Maintenance of Pneumatic Butterfly Valve Dec 12, 2020
    Pneumatic butterfly valve is a newly developeddurable energy-friendly butterfly valve.This kind of butterfly valve adopts new technologies such astriple eccentric design, elastic sealing,multilevel hard and soft sealing processing, so that the butterfly valves are more than reliable and they can achieve no leakageingas sealing. The pneumatic actuator adopts curved arm conversion structure, which has the characteristics of large output torque, small volume, stable and reliable performance, etc. It can be used with valve positioner. Or used in conjunction with solenoid valves, the device can achieve proportional regulation or switching control and is suitable for media such as gases, solid particles and liquids. Pneumatic butterfly valve can be widely used in paper, petrochemical, chemical, metallurgy, electric power, environmental protection, petroleum, light industry, building automation and automation control system of otherindustrial sectors. Installation and maintenance of pneumatic butterfly valve. 1. When installing the butterfly valve, you should pay attention to the flow direction mark on the valve body to avoid the wrong direction of flow and affect the use. 2. Beforethe use ofthepneumatic butterfly valve, you should flush the pipeline with the valve fully open to avoid the sealing surface being scratched by debris such as welding slag. 3. Generally, bypass piping will be set next to the butterfly valve so that when the butterfly valve is serviced or replaced, the bypass piping can be used to carry out the process as usual. 4. Pneumatic butterfly valve can be installed vertically within 180°。And do not install the pneumatic actuator upside down. 5. If you find that the stuffing box is leaking during use, tighten the gland bolts to solve the problem. Here atDervos, we’re a leading provider for products inindustrial valve, and we’re certified with theCE, ISO, API and other institutions. We strive to offer the best quality products and customer service through our extensive experience. Contact us today for more information—we can’t wait to work with you!
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  • Six Factors to Consider When Selecting Valve Seal Face Material
    Six Factors to Consider When Selecting Valve Seal Face Material Dec 02, 2020
    There are six major factors to consider when selecting valve sealing face materials. The sealing surface is the most critical working surface of the valve, the quality of the sealing surface directly affects the service life of the valve, and the sealing surface material is an important factor to ensure the quality of the sealing surface. Therefore, the following factors should be considered when selecting the valve sealing surface material. Corrosion Resistance. "Corrosion" is the process by which the surface of a sealingpart is damaged by medium. If the surface is damaged in this way, the sealability cannot be guaranteed; therefore, the sealing face material must be corrosion resistant. The corrosion resistance of a material depends mainly on its tensile strength and its chemical stability. Abrasion resistance. "Abrasion" is the damage caused by friction during the relative movement of the sealing surface. This damage will inevitably lead to the destruction of the sealing surface, therefore, the sealing surface material must have good anti-scuffing properties, especially the gate valve. The abrasion resistance of the material is often determined by the internal properties of the material. Erosion resistance."Erosion"refers thatthe medium flows through the sealing surface at high speed, so that the sealing surface is damaged. This damage is more obvious in the high temperature, high pressure steam medium used in the globe valve, safety valve. the sealing damage has a great impact, therefore, erosion resistance is also one of the important requirements of the sealing surface material. It should have acertain hardness, and the hardness decreases greatly under the specified working temperature. The coefficient of linear expansion of the sealing face and the body material should be similar, which is more important for the structure of the inlaid seal, in order to avoid additional stress and lose under high temperature. For use at high temperatures, there should be adequate resistance to oxidation, thermal fatigue, andthermal cycling issues. In the current situation, it is very difficult to find a sealing surface material that fully meets the above requirements. For example, for valves used in high speed media, specific attention should belaidto the requirements of erosion resistance of the sealing surface; when the medium contains solid impurities, sealing surface materials with higher hardness should be selected. Here at Dervos, we’re a leading provider for products inindustrial valve, and we’re certified with the CE, ISO, API and other institutions. We strive to offer the best quality products and customer service through our extensive experience. Contact us today for more information—we can’t wait to work with you!
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