Large diameter welded ball valves are important valve products commonly used in industrial production, and their safety in use is crucial. If installed improperly, there may be safety issues of uneven force distribution, and in severe cases, it may cause harm to personnel and equipment; It may also cause problems such as valve damage and leakage, thereby shortening the service life of the valve. Below, we will introduce the precautions for installing this large fully welded ball valve from four major aspects. 1. Pipeline inspection Before installation, it is necessary to ensure that the pre-treatment work of the pipeline has been completed, including cleaning the internal and surrounding areas of the pipeline, removing foreign objects and rust, etc. 2. Valve lifting (1) When lifting a ball valve, the lifting rope should be tied to the lifting lug (ring) or flange on the valve body, and should not be tied to the handwheel, valve stem, or actuator to avoid damage to the actuator. (2) During the lifting process, the blind covers at both ends of the ball valve should not be removed to prevent dust and foreign objects from entering the chamber. It is necessary to avoid hitting the ball valve and colliding with pipeline accessories or joints. Do not use chain lifting, but use soft belts for lifting. Take corner protection measures at the edge of the valve to ensure that the external paint of the valve is not damaged during the lifting process. 3. Valve inspection before installation (1) Determine the switch position. The ball valve is in the fully open position when leaving the factory, and when installed on the pipeline, it is generally necessary to keep the valve in the fully open position. When it is necessary to install in the fully closed position, appropriate protective methods can be confirmed in advance with the manufacturer. (2) Inspection of installation direction and position. Before installation, carefully check whether the valve nameplate and identification match the installation and usage requirements. (3) Clean the inner chamber and sealing surface of the valve. Dirt is not allowed to adhere to the cavity. If there is, a clean soft cloth should be used to wipe off the attached dirt before installation. (4) Drive device inspection. Before installation, check whether the drive device operates flexibly, whether there is any jamming, whether the bolts and nuts are loose, whether the packing is tight, and whether the valve switch status is consistent with the installation requirements. 4. Welding of valves and pipelines (1) Before welding with the pipeline, the surface of the pipeline and ball valve welding joints must be cleaned to remove impurities such as dust and oil to ensure the quality and strength of the weld. (2) The size and shape error of the ball valve piping should be within the allowable range and consistent with the centerline of the main pipe before welding. (3) Before welding, cover the sealing surface area of the valve with ...

The core components of elastic seat sealed gate valves mainly include valve bodies, valve covers, valve stems, and gate plates. The gate is made of ductile iron covered with non-toxic rubber (directly vulcanized nitrile rubber or EPDM rubber). The sealing of the entire valve mainly relies on the contact between the rubber gate and the casting, achieving a good sealing effect through the slight elastic deformation caused by the stress on the rubber. Characteristics 1. Flat bottom valve seat Traditional metal gate valves often fail to close tightly after being cleaned with water due to foreign objects such as stones, wooden blocks, cement, iron filings, and debris accumulating in the grooves at the valve bottom, resulting in water leakage. The elastic seat sealing gate valve adopts a flat bottom design with no grooves at the bottom of the inner chamber and the same bottom as the water pipe, which is not easy to cause debris accumulation and the sealing is consistent. 2. Overall sealing of the wedge The gate is made of high-quality rubber for overall internal and external sealing, ensuring accurate geometric dimensions of the vulcanized gate. The rubber is firmly attached to ductile iron and is not easy to fall off, with good elastic memory. 3. All parts meet environmental requirements The valve body, valve cover, bracket, handwheel and other parts of the elastic seat sealed gate valve are all made of ductile iron. After special treatment, the internal and external surfaces are sprayed with epoxy resin powder coating using high-pressure electrostatic spraying technology. The internal components are made of stainless steel or copper alloy, effectively preventing the formation of corrosion, and are pollution-free, non-toxic, and have a beautiful surface. 4. Low flow resistance and low head loss Due to the use of spraying technology, the epoxy resin coating surface of the elastic seat sealed gate valve is very smooth, greatly reducing the surface roughness of the channel through which the medium flows, resulting in small flow resistance and low head loss. At the same time, the bottom of the valve body is designed as a straight through type, which also reduces flow resistance and head loss. 5. Special shaft seal Due to the use of three O-ring seals and one dust ring seal design on the valve stem, it can reduce friction resistance during switching and significantly reduce water leakage. 6. Protective devices Elastic seat gate valves that can be directly buried underground are equipped with a set of protective devices. There is a valve box on the top of the device, and when opening the cover plate on the valve box, an extended socket wrench can be used to open and close the valve. The elastic seat sealing gate valve is reliable in sealing, can achieve zero leakage, and has a small friction coefficient and minimal wear. The valve has small torque when opening and closing, easy operation, long service life, no pollution, corrosion resistance, and beautiful ...

Metal sealed triple eccentric ball valve is a new product used in high temperature, high pressure, and harsh process medium requirements. Advantages Compared with ordinary soft-sealed ball valves (1) Can be adapted to a wider temperature range. Soft-sealed ball valves are affected by the temperature resistance of non-metallic seals and cannot be used in situations where the temperature is too high. The metal seal can be used at 600 ℃ or even higher according to different materials. (2) Can be used in higher pressure range. Limited by the pressure resistance of non-metallic materials and stability under high pressure, non-metallic sealed ball valves are used for CL600 or lower grades. When used at higher pressure levels, non-metallic seals are prone to instability and cause valve failure. The metal hard seal ball valve can be used in CL2500 class. (3) A longer service life can be obtained. Compared with metal materials, non-metallic materials are prone to aging. After a period of use, the performance degradation of non-metallic materials will cause the valve sealing performance to also decrease. On the other hand, non-metallic materials are susceptible to damage. When the fluid contains solid particles, non-metallic seals are easily scratched, resulting in seal failure or reduced seal performance. Compared with ordinary metal hard-sealed ball valves (1) Fixed ball design. Ordinary ball valves are sealed with floating balls, while triple eccentric ball valves are all designed with fixed balls, and the specific pressure of the seal is established by its own torque, which is reliable under any circumstances. (2) Torque seal design. Traditional metal hard seal trunnion ball valves usually have a pre-compressed spring behind the valve seat. Under the action of the spring, the valve seat is in contact with the sealing surface of the ball to form a sealing specific pressure. If the spring stiffness is too small, the formed sealing specific pressure is also relatively small, and the sealing effect is poor; if the spring stiffness is high, the wear of the sealing surface will be increased, and the switching torque will be increased at the same time; on the other hand, the spring is affected by the temperature of the medium. Its stiffness tends to change over time, and therefore the sealing effectiveness also changes over time. The triple eccentric ball valve is sealed by torque, which can form a larger sealing specific pressure, and it will not wear a lot, and it will not be affected by temperature and alternating load. (3) Bi-directional sealing performance of single valve seat. Under low temperature conditions, the traditional metal hard sealing ball adopts complex automatic pressure relief mechanism or adopts the method of opening holes in order to release the medium in the valve cavity. The former increases the complexity of the valve seat, and the latter makes the ball valve directional because of the opening. The triple eccentric ball valve adopts a ...

Axial flow check valves can be divided into sleeve, disk, ring, and other forms according to their disc structure. In addition to the functions of general check valves, the axial flow check valve is also designed with shock absorbing springs. The combined valve seat sealing structure with hard seal and soft seal has the effect of noise reduction and shock absorption, which is convenient for users to overhaul on site. The unique axial flow shuttle structure has the advantages of small flow resistance, large flow coefficient and small size. It is suitable for pipeline systems such as oil, gas, water slurry and acidic corrosive media containing H2S+CO2, and is used to control the reverse flow of the medium. Structural Characteristics 1. It is designed with shock-absorbing spring, which avoids the vibration and noise caused by the direct impact between the disc and the valve body when the ordinary check valve is opened. 2. The valve seat adopts a combined sealing structure of hard seal and soft seal, which has better sealing performance. 3. Compact structure, beautiful shape, small size. 4. Unique axial flow shuttle structure, small flow resistance and large flow coefficient. Working Principle The opening and closing of the disc is determined by the pressure difference between the inlet and outlet of the valve. When the pressure at the inlet port is greater than the sum of the pressure at the outlet port and the spring force, the disc opens. As long as there is a pressure difference, the disc is always open, but the degree of opening is determined by the size of the pressure difference. When the sum of the pressure at the outlet end and the spring force is greater than the pressure at the inlet end, the disc closes and remains closed all the time. Since the opening and closing of the disc is in a dynamic force balance system, the valve operates smoothly, without noise, and the phenomenon of water hammer is greatly reduced. The axial flow check valve closes quickly and without impact. The disc with small mass and low inertia touches the seat surface with a very small impact force after a short stroke, which can keep the sealing surface of the valve seat in good condition and avoid damage. More importantly, it can minimize the formation of pressure fluctuations and ensure system safety.

The advantages of butterfly valves are simple structure and good sealing effect; the disadvantage is that there is some disturbance to the water flow when the butterfly valve is fully open. Structural Characteristics The basic structural forms of butterfly valves are double offset and triple offset butterfly valves. The operating mechanisms of butterfly valves are usually manual, worm gear, electric, pneumatic, etc. Butterfly valves mainly consist of valve body, disc, shaft, sealing device, bracket, and control device. Manufacturing Guidelines The main function of butterfly valves is to seal water, steam, oil, etc. Therefore, the manufacturing guidelines for butterfly valves are to ensure reliable sealing, accurate and flexible operation. The sealing of butterfly valves mainly includes the main sealing between the valve body and the disc, the bearing composite sealing at the shaft part, and the sealing at the joints of various components. To ensure reliable sealing of butterfly valves, it is necessary to ensure that the dimensions, surface roughness, and positional tolerances of these parts meet the requirements of the drawings. It is also important to ensure that the dimensions, surface roughness, positional tolerances, etc. of all components meet the requirements of the drawings. The application range of butterfly valves is also quite wide. If they are used to control the flow rate, different types and valve body sizes need to be selected. Butterfly valves are widely used not only in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems of thermal power plants.

Line blind valve is a kind of gate valve that cuts off gas medium manually, electrically or pneumatically or hydraulically. It is generally divided into electric blind valve, hydraulic blind valve, closed plug valve and electric open blind valve. Basic Structure Line blind valve is composed of left and right valve bodies, telescopic movement mechanism, fan-shaped valve plate, electric control push rod Ⅰ for driving the valve plate, and electric push rod Ⅱ for clamping and loosening. Principle Introduction Line blind valve has three driving devices, including two manual clamping or loosening devices, and an electric device for opening or closing the gate. When opening or closing the gate, first loosen the two manual devices, and then start the electric device to open or close the gate (special note: the electric device is allowed to open only after the two manual devices are released). After the gate is opened or closed, the two manual devices are clamped, and the pipeline can work. Features Line blind valve, also known as spectacle valve, electric disc valve, is mainly composed of left valve body, right valve body, sector gate, stainless steel bellows, electric transmission device, electric clamping device and other components. The valve body adopts a three-point locking sector gate structure. The sealing adopts stainless steel and rubber sealing ring, which has good sealing performance and long service life. The sealing ring is installed on the gate plate, which is convenient for maintenance and replacement. Line blind valve is operated electrically, with stable operation, flexible start and reliable action.