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  • Mount Wuyi Witnessed the 14th Anniversary of DERVOS
    Mount Wuyi Witnessed the 14th Anniversary of DERVOS Jul 07, 2022
    In an instant, fourteen years have passed. Unconsciously, we ushered in the 14th anniversary of Dervos. During these 14 years, through continuous practice and learning, Dervos have withstood countless tests and worked tenaciously in this rapidly developing new era. In order to celebrate the birhday of Dervos, we gave up the monotonous indoor entertainments and embraced nature this year, went to Mount Wuyi, which is known as one of the "World Cultural and Natural Heritage Sites". In order to have an enough leisure holiday so that everyone can have a full rest, CEO Eric arranged for us five days to enjoy nature. After breakfast at the B & B every morning, we will follow the tour guide to the scenic spots of Mount Wuyi: Dahongpao scenic spot, Tianyou peak, Yunv peak, yixiantian, bamboo raft rafting, etc. It has to be said that mountain climbing is a challenging sport for a group of urban beauties who are always accompanied by computers! Nevertheless, everyone is enthusiastic and determined to reach the top. Maybe you will see some breathless figures in the process of climbing, but thanks to Ken, Judy, Matthew and others who have good physical strength to help us explore the way and encourage us to insist, so we can have so many group photos of the top of the mountain! In addition to climbing, the most amazing thing is the live performance of impression Dahongpao, which is directed by Zhang Yimou, Wang Chaoge and Fan Yue, with nearly 300 actors. It uses the world's first 360 degree rotating auditorium, you can see different scenes every time you rotate. It shows the history of tea, tea making technology. The antique pavilions brought us back to the past. Although the Mount Wuyi trip is over, the valve journey of Dervos is continuous. We will continue to provide you with high quality valves and considerate services! Let's develop together!
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  • Dervos' Products were Exhibited in EXPONOR 2022!
    Dervos' Products were Exhibited in EXPONOR 2022! Jun 23, 2022
    Exponor, an exhibition that takes place in Antofagasta - Chile every two years, links the latest advances aimed at the mining sector. It has a complete program of activities aimed at generating business opportunities and strengthening and establishing business networks at the national and international level. This year's exponor has been held from June 13 to 16, 2022. The industries participating in this exhibition include heavy equipment, process equipment, machinery, engineering services and electrical goods, automation, and control, etc. Our partner, the exclusive agent in Chile participated in exponor with our products. ①High Performance Butterfly Valve ▼Double offset, soft seated ▼Design: API609 ASME B16.34 ▼Pressure: Class 150-Class 600 ▼Size: 2”-60" ▼Material: Carbon Steel, Stainless Steel, Alloy Steel ②Metal Sealed Butterfly Valve ▼Triple offset, metal seated ▼Design: API609 ASME B16.34 ▼Pressure: Class 150-Class 1500 ▼Size: 2"-60” ▼Material: Carbon Steel, Stainless Steel, Alloy Steel ③Knife Gate Valve ▼Uni-directional or bi-directional, soft or metal seated ▼Design: MSS SP 81 ▼Pressure: Class 150 ▼Size: 2"-60" ▼Material: Carbon Steel, Stainless Steel, Alloy Steel, Ductile Iron ④Lined Ball Valve ▼Design: ASME B16.34 ▼Pressure: Class 150 ▼Size: 1/2"-16” ▼Material: Carbon Steel, Stainless Steel They all can be customized according to your needs! In May of 2022, DERVOS won a project which end user is AngloAmerican and application is iron ore mining. With this success, DERVOS is ready for more projects in mining industry.
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  • Common Malfunctions and Solutions of Knife Gate Valve (I)
    Common Malfunctions and Solutions of Knife Gate Valve (I) Jun 16, 2022
    The opening and closing part of knife gate valve is wedge. The movement direction of the wedge is perpendicular to the fluid direction. Knife gate valve can only be fully opened and closed, can’t be adjusted or throttled. Next, let's learn about the common malfunctions and solutions of knife gate valve in the application process with Dervos! 1. Leakage of Closing Parts of Knife Gate Valve (1) Reasons of Leakage ① The sealing surface of knife gate valve is not well ground; ② The sealing ring is not tightly matched with the valve seat and disc; ③ Valve disc and valve rod are not firmly connected; ④ The valve rod is bent and twisted to make the upper and lower closing parts misaligned; ⑤ Closing too fast, resulting in poor contact or damage of sealing surface; ⑥ Improper material selection makes the valve unable to withstand medium corrosion; ⑦ Some media gradually cool down after the valve is closed, resulting in fine cracks on the sealing surface and erosion; ⑧ The valve can’t be closed tightly due to the embedding of welding slag, rust, dust and other impurities, or the valve core is blocked due to the falling off of mechanical parts in the production system. (2) Solutions ① Conduct pressure test carefully before use. If leakage is found on the sealing surface or the root of the sealing ring, handle it before use; ② Check whether all parts of the valve are in good condition in advance. Do not use the valve with bent valve rod or the valve disc is not firmly connected with the valve rod; ③ The valve should be closed firmly without strong force. In case of poor contact or obstruction between sealing surfaces, it should be opened a little immediately to let sundries flow out, then closed tightly; ④ When selecting the valve, we should consider the corrosion resistance of the valve body and closing parts; ⑤ It should be used correctly according to the structural characteristics of the valve; ⑥ In case of medium cooling and large temperature difference after valve closing, close the valve after cooling; ⑦ A filter should be added to the valve that may enter impurities. 2. Filler Leakage of Knife Gate Valve (1) Reasons of Leakage ① The filler does not adapt to the corrosion, temperature and pressure of the working medium; ② The filling method is wrong. In particular, the whole filler is placed in a spiral, which is most likely to cause leakage; ③ The machining accuracy or surface finish of the valve rod is not enough, there are ellipses or nicks; ④ The valve rod has pitted or rusted due to open air; ⑤ The valve stem is bent; ⑥ The filler has been used too long and aged; ⑦ Operation is too fierce. (2) Solutions ① Proper filler selection; ② Correct method of filling; ③ If the processing of valve rod is unqualified, repair or replace it; ④ Protective measures should be taken to prevent corrosion; ⑤ The bent valve rod should be straightened or renewed; ⑥ The filler should be replaced after a certain period of use; ⑦ Pay attention to stable operation. Open a...
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  • A New Type of Valve - Three-way Ball Valve
    A New Type of Valve - Three-way Ball Valve Jun 08, 2022
    Ball valve is a new type of valve widely used in recent years.Three-way ball valve is a relatively new type of ball valve. It has unique advantages in its own structure. It is widely used in petroleum, chemical industry, urban water supply and drainage and other working conditions requiring cut-off, diversion and confluence. Features of Three-way Ball Valve: 1. Integrated structure, less flange connection and high reliability; 2. Long service life and large circulation capacity; 3. According to the structural form, the three-way ball valve can be divided into L-type, T-type and Y-type. Different structural forms are selected according to different working conditions. Advantages of Three-way Ball Valve: 1. Low fluid resistance. Its resistance coefficient is equal to the pipe section with the same length; 2. Simple structure, small volume and light weight; 3. Tight and reliable, good sealing performance. It has been widely used in vacuum system; 4. Easy operation and quick opening and closing.It only needs to rotate 90° from full open to full close. It facilitates remote control; 5. Convenient maintenance. The sealing ring is generally movable, which is convenient for disassembly and replacement; 6. When the valve is fully open or closed, the sealing surface of the ball and valve seat is isolated from the medium. When the medium passes through, the valve sealing surface won’t be eroded. 7. Wide range of application. The diameter of three-way ball valve is as small as a few millimeters and as large as a few meters. It can be used in high vacuum and high pressure environments. Precautions for Maintenance of Three-way Ball Valve: 1. The valve handle rotation position should be reserved; 2. It can’t be used as throttling; 3. Ball valve with transmission mechanism should be installed vertically.
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  • Design and Structural Features of Forged Steel Gate Valves
    Design and Structural Features of Forged Steel Gate Valves Jun 01, 2022
    Forged steel gate valve is a gate valve forged with metal steel materials. Forged steel gate valves are widely used. They are mainly used for cutting off in pipelines. They can only be fully opened and fully closed, can’t be used for regulation and throttling. Design Form of Forged Steel Gate Valve Bonnet: (1) Bolted bonnet. According to this design form, the valve body and bonnet are connected with bolts and nuts and sealed with spiral wound gaskets (316 clamp flexible graphite manufacturing). Metal ring connection can also be adopted for customers' special requirements; (2) Welded bonnet. According to this design form, the valve body and bonnet are connected by thread and sealed by full welding. Full penetration connection can also be adopted for customers' special requirements; (3) Pressure self-tightening bonnet. According to this design form, the valve body and bonnet are connected by thread and sealed by internal pressure self-sealing ring. Structural Features of Forged Steel Gate Valves: (1) Low fluid resistance; (2) Small size, light weight; (3) Good sealing performance, widely used in vacuum system; (4) Simple structure, easy disassembly and replacement. Precautions for Forged Steel Gate Valve: (1) Pay attention to the pressure and temperature of forged steel gate valve; (2) Pay attention to the switch position of forged steel gate valve; (3) Pay attention to the blowdown and blockage of forged steel gate valve body; (4) Pay attention to the diameter of forged steel gate valve is flush with the seal ring seat.
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  • About Stainless Steel Gate Valve
    About Stainless Steel Gate Valve May 25, 2022
    1、Classification of Stainless Steel Gate Valves: 2、Advantages of Stainless Steel Gate Valve: 1. It has low fluid resistance, the sealing surface is little scoured and eroded by the medium; 2. Opening and closing is labor-saving; 3. The flow direction of media is unrestricted; 4. Good manufacturing technology, reliable sealing performance, corrosion resistance and wide application range. 3、Disadvantages of Stainless Steel Gate Valve: 1. It is easy to cause erosion and scratch between sealing surfaces; 2. The overall dimension is large, so it needs a certain space for opening, the opening and closing time is long; 3. Complex structure. 4、Precautions for Installation of Stainless Steel Gate Valve: 1. It is generally installed horizontally in the pipeline; 2. Hand wheel, handle and transmission mechanism are not allowed to be used for lifting, and collision is strictly prohibited; 3. The bypass valve should be opened before the gate valve with bypass valve is opened (To balance the pressure difference between the inlet and outlet and reduce the opening force); 4. The gate valve with transmission mechanism should be installed according to the provisions of the product operation manual; 5. If the valve is opened and closed frequently, lubricate it at least once a month.
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