The ball of floating ball valve is floating. Under the action of medium pressure, the ball can produce certain displacement and press tightly on the sealing surface at the outlet end to ensure the sealing at the outlet end. Structure 1. The valve stem should be inverted, anti-blowout structure. The valve stem of the valve should not be limited by the packing gland fasteners. To be precise, the valve stem will not be separated from the valve due to the loosening of the valve stem sealing fasteners when the valve is under pressure. 2. Anti-static structure. It consists of a stainless steel ball and a spring. One group is placed in the hole at the end of the valve stem, keeping in contact with the ball; the other group is placed on the cylinder of the valve stem, keeping in contact with the valve body, so that the possible static electricity is guided away from the valve body. 3. Fire-safe structural design. When the sealing seat is burned, the main and auxiliary valve bodies should be in contact with the sphere and maintain a certain degree of sealing. The connecting surfaces of the main and auxiliary valve bodies shall adopt gaskets with fire safety functions, such as metal wound gaskets. At the packing seal of the valve stem, when the packing (PTFE) is burned, there should be a graphite ring to prevent the medium from leaking out. 4. There should be a limit mechanism to accurately limit the ball to be in the "open" or "close" position. 5. There should be a platform for installing pneumatic, electric and worm gear actuator brackets on the valve body. Sealing Principle The opening and closing part of the floating ball valve is a sphere with a through hole equal to the diameter of the pipe in the middle. The inlet and outlet ends are each equipped with a sealing seat made of PTFE, and are contained in a metal valve body. When the through hole in the sphere coincides with the pipeline channel, the valve is in the open state; when the through hole in the sphere is perpendicular to the pipeline channel, the valve is in the closed state. When the ball valve is in the closed position, the medium pressure at the inlet end acts on the ball, generating a force to push the ball, making the ball press the sealing seat at the outlet end tightly, and a contact stress is generated on the tapered surface of the sealing seat to form a contact zone. The force per unit area of the contact zone is called the working specific pressure of the valve seal. When this specific pressure is greater than the necessary specific pressure for sealing, the valve is effectively sealed. This kind of sealing method that does not rely on external force is sealed by medium pressure, which is called medium self-sealing.

Vacuum ball valve refers to a ball valve whose working pressure is lower than the standard atmospheric pressure and forms a certain vacuum. Its working principle is similar to that of a vacuum butterfly valve, and the valve is opened and closed by rotating the ball fixed on the rotating shaft by 90°. Because the valve body and stem are made of stainless steel in its structure, and the sealing materials such as the valve seat and packing are all polytetrafluoroethylene, it is suitable for working conditions where the medium is air, water, steam, acid, alkali, etc. Features 1. It adopts 1/4 rotary pneumatic or electric actuator, which works smoothly, and the valve switch has electric signal output, which can be used both by hand and by electricity; 2. It not only has simple structure and good sealing performance, but also has small installation size, small driving torque, simple operation, and easy to realize rapid opening and closing; 3. It can be used in a high vacuum state or a low pressure system to achieve the advantages of both positive and negative pressure. Connection Forms (1) Flange connection: This is the most commonly used connection form in valves. According to the shape of the joint surface, it can be divided into the following types: ① Smooth type: used for valves with low pressure, it is more convenient to process; ② Concave-convex type: the working pressure is relatively high, and medium-hard gaskets can be used; ③ Tongue and groove type: gaskets with large plastic deformation can be used, which are widely used in corrosive media and have good sealing effect; ④ Trapezoidal groove type: use oval metal ring as gasket; ⑤ Lens type: The gasket is in the shape of a lens and made of metal; ⑥ O-ring type: It is a relatively new flange connection form developed with the emergence of various rubber O-rings, and its sealing effect is more reliable than ordinary flat washers. (2) Threaded connection: This is a simple connection method, often used in small valves. It is divided into two situations: ① Direct sealing: The internal and external threads directly play a sealing role. ② Indirect sealing: The power of thread tightening is transmitted to the gasket between the two planes, so that the gasket acts as a seal.

Time flies, Dervos people go hand in hand with the company. Among them, Yvonne, Aries, Stella and Trista have joined Dervos for 5 years, Alice and Rachel have joined Dervos for 10 years. Every year, Dervos will give awards to anniversary employees. This year, Dervos also prepared many exquisite gifts for these families. We secretly collected and edited their photos and videos since 2013. We watched the video together and recalled the warm memories of the past, which made people feel unforgettable and tearful. After watching the memory video, our general manager Eric and sales manager Ken presented awards to the anniversary employees to thank them for their dedication to the company. Because of you, Dervos can become a warm, harmonious and loving family. Thank you for being there all the time! Dervos sincerely hopes that everyone can accompany Dervos through the following countless five and ten years. All along, Dervos attaches great importance to the introduction of high-quality talents, which adds a lasting and strong impetus to the development of the enterprise; pays attention to the sustainable development of talents, provides sufficient training for each employee; pays attention to the personal development of employees, and provides employees with open and equal career development channels. Therefore, Dervos has a more experienced, professional and stable team, which can bring better cooperation experience and considerate service to our partners.

For Dervos, 2022 is a meaningful, valuable and rewarding year. With the busy and hard work, we unknowingly ushered in 2023. On February 3, 2023, Dervos held the 2022 annual meeting. First, the heads of each department gave a brief description of the work content of their department. They summarized the achievements and deficiencies of the past year, and also formulated the development direction and goals for the coming year. Then, Eric, our general manager summarized the major achievements of Dervos in 2022: ①Major orders are delivered on time with high quality; ②On the basis of maintaining the original certificate, a variety of certificates have been added; ③Have more in-depth cooperation with customers; ④Sales performance hit a record high. In addition, Eric also pointed out the existing problems and encouraged everyone to learn from experience and make progress together. At the end of the meeting, Eric planned the development direction for 2023, and put forward the key words of Dervos: "Going Out" and "Coming In". So we will have more opportunities to communicate face-to-face with our partners and enhance communication. After the successful conclusion of the annual work summary, we ushered in the annual dinner. The highlight of this dinner is "Cash Bo Bing". "Cash Bo Bing" has the same rules as regular Bo Bing, except that the rewards are changed to cash, which is more thrilling and exciting! This time, we divided into three tables: A, B and C. During the Bo Bing, everyone was very enthusiastic and lively. In the end, Ken at table A, Sam at table B, and Trista at table C won the first prize and took away the grand prize! On this special day, Dervos is grateful to all business partners for their trust. Because of you, Dervos can develop more calmly, firmly and rapidly in the future. Dervos has excellent and responsible employees, so we can better understand your needs and continue to provide more professional and meticulous services. Let's create a better tomorrow together!

Wedge gate valve is a kind of gate valve. It is named for its sealing surface and vertical center line at a certain angle, that is, the two sealing surfaces are wedge-shaped. Wedge gate valves are divided into rising stem wedge gate valves and non-rising stem wedge gate valves. In the rising stem wedge gate valve, the stem moves up and down, and the stem nut is fixed. The non-rising stem gate valve has a fixed stem, and the disc moves up and down to complete the opening and closing. The driving methods include: electric, pneumatic, manual, gas-hydraulic, etc., and the connection methods adopt flange type, welding type, and wafer type. Working Principle The opening and closing part of the wedge gate valve is the wedge, and the movement direction of the gate is perpendicular to the direction of the fluid. Wedge gate valve can only be fully opened and fully closed, not suitable for regulation and throttling. Wedge gate valve generally completes the opening and closing of the valve by moving the valve stem up and down with the rotating hand wheel. Structural Characteristics 1. Compact structure, reasonable design, light and flexible, good rigidity of the valve, smooth passage, small flow coefficient; 2. The sealing surface is made of stainless steel and hard alloy, which has a long service life; 3. With flexible graphite packing, the seal is reliable. Application Range Wedge gate valve is widely used in electric power, petroleum, chemical industry, metallurgy, mining, sewage treatment and other industrial fields, especially in the ash removal and coal washing plant equipment of power stations.

Resilient seated sealing gate valve utilizes the compensation effect of the elastic deformation of the overall rubber covering of the gate to achieve a good sealing effect, and overcomes the problems of poor sealing, water leakage and rust in general gate valves. Resilient seated sealing gate valve can be widely used in tap water, sewage, construction, petroleum, chemical industry, food, medicine, textile, electric power, shipbuilding, metallurgy, energy system and other working conditions, and it is used as a shut-off device on the fluid pipeline. Features of Resilient Seated Sealing Gate Valve: 1. Flat-bottom valve seat, no dirt accumulation, more reliable sealing. 2. The wedge is covered with nitrile rubber as a whole, and the internal parts of the valve are made of corrosion-resistant stainless steel and copper alloy materials, which can be used in the sewage system and adapt to the harsh working environment. 3. Small size, light weight, easy to install and maintain. 4. The valve stem is sealed with three O-rings, which greatly reduces the friction resistance when switching, and the switch is light and water-proof. 5. The valve body is made of precision casting, and the precise geometric dimensions make the valve body tight without any finishing work. 6. The copper nut and the elastic wedge are embedded in the joint, so that the two are closely integrated into one body, and there is no loosening or damage caused by the vibration caused by the water flow. 7. The valve body is coated with powder epoxy resin, which can prevent corrosion and rust of the valve body and can be used in sewage system. 8. The inside of the valve body is coated with non-toxic epoxy resin, and the inner and outer surfaces of the valve are completely covered with rubber, which will not rust or corrode, and can be used for raw drinking.