Overview of gate valves：
If you want to learn more, please visit our website direction open valve.
Gate valves are one of the most common types of valves in the isolation category. They can be found in every refinery, chemical plant, power station, and industrial production facility, and can be manufactured in sizes ranging from DN6 to 4200. gate valves are chosen for the primary purpose of fluid shutoff. It is for this reason that gate valves are often referred to as "cut-off" or "blocking" valves.
Gate valves are generally used in the fully open or fully closed operation. When fully open, the pressure drop through the gate valve is very small; when fully closed, the pressure sealing performance is very good. Due to the fit of the gate and seat ring, there is almost no leakage when the gate valve is closed. However, in the case of very low back pressure (generally not less than 0.34 bar, 1 bar = 105 Pa), some leakage may occur.
Another advantage of gate valves is that they usually open and close very slowly, a feature that prevents fluid water hammer effects from damaging the piping system.
The main limitation of gate valves is that they cannot be used in throttling conditions. When gate valves are used in dry throttling service, the fluid often has a high flow rate near the seat, which can cause erosion. Also in the partially open state, the gate will swing under the impact of the medium, which will cause damage to the seal. Usually, gate valves are more prone to seat and gate seal surface wear than globe valves, and the repair of such wear is difficult to be accomplished by means of grinding and polishing.
Because the structural characteristics of the gate valve are very suitable for large-scale devices, its application range is expanding, and to high temperature and high-pressure development. The maximum diameter of the gate valve has reached DN4200, in the ammonia plant has been a large number of high-pressure gate valve PN320, for oil and gas drilling wellhead gate valve working pressure up to 138MPa. manufacturing a high-temperature and high-pressure gate valve is the key to solving the problem of wedging the gate plate due to temperature changes, as well as ensuring its reliable sealing performance. To this end, the gate and seat sealing structure should be studied and improved. Resilient seats and resilient floating seats have begun to be applied to enable the gate valve to achieve inlet sealing, outlet sealing, or double sealing of import and export.
Composition of gate valve：
Gate valve, also called the gate valve, mainly consists of the valve body, bonnet, gate, stem, seat and seal packing, and other parts.
The gate valve is the opening and closing member (gate), driven by the valve stem, along the seat (sealing surface) to do a linear movement of the valve. Generally, the gate valve can not be used to regulate the flow, only a cut-off device can be used, either completely open or completely closed. Among the various types of valves, the gate valve is the most widely used one. It is suitable for both normal temperature and pressure conditions, as well as high and low temperature and high and low-pressure conditions, and can be applied to a variety of different media through the selection of different materials.
Are you interested in learning more about open and close valve? Contact us today to secure an expert consultation!
The advantages of the gate valve:
①Small fluid resistance. Gate valve body's internal media channel is straight, the media flow through the gate valve does not change its flow direction, so the fluid resistance is small.
② structure length (the distance between the two ends connected to the pipe) is small. As the gate is disc-shaped, is placed vertically in the body of the valve, and the globe valve flap (also disc-shaped) is placed parallel to the body of the valve, so compared with the globe valve, its structure length is smaller. Such as the PN16, and DN150 globe valve, the structure length of 480mm, while the same parameters of the gate valve structure length are only 350mm.
③ opening and closing less effort. When opening and closing the gate movement direction is perpendicular to the direction of media flow, while the shut-off valve flap is usually closed in the direction of movement and seated in the opposite direction of media flow, and therefore must overcome the force of the medium. Therefore, compared with the shut-off valve, the opening, and closing of the exposition valve is more labor-saving.
④ Media flow direction is not restricted. The medium can flow from both sides of the gate valve in any direction through the gate valve and can achieve the purpose of connection or cut off. Easy to install, suitable for the flow direction of the medium may change in the pipeline.
⑤ When fully open, the sealing surface is subject to minimal erosion of the working medium.
⑥The structure of the body is relatively simple, and the manufacturing process is good.
Disadvantages of the gate valve:
①Sealing surface is easy to produce abrasions. When opening and closing the gate and the valve seat in contact with the relative sliding between the two sealing surfaces, under the action of the medium thrust easy to produce abrasion, thus destroying the sealing performance, and affecting the service life.
② more parts, the structure is more complex, manufacturing and maintenance are more difficult, compared with the cost of the globe valve are higher.
③ shape size and opening height are larger, and the space required for installation is larger.
④Generally gate valves have two sealing pairs, which adds some difficulties to processing, grinding, and maintenance.
⑤ The operating stroke is large, and the opening and closing time is long. Since the gate needs to be completely lifted to the top of the seat channel when opening, and all the gate needs to fall down to block the seat channel when closing, so the opening and closing stroke of the gate is large, and the opening and closing time is long.
This article will explain the advantages and disadvantages of gate valves and the scope of application. A gate valve is a valve in which the opening and closing part moves along the vertical direction of the pipeline channel axis. The
opening and closing part is called a gate, which is mainly used to cut off the flowing medium in the pipeline and can only be used fully open or fully closed. Therefore, the gate valve cannot be used as a regulating valve to regulate flow. Gate valves of different materials are adapted to different environments and temperatures, but gate valves are generally not used in pipelines that transport mud and other media, because these media contain impurities, which will affect the sealing effect of the gate.
Advantages of gate valve:
1. It can only be fully open and fully closed. When the gate is fully open, the resistance of the fluid through the valve is small;
2. The torque required for opening and closing is small and labor-saving;
3. It can be used in pipelines where the medium flows in both directions, and the flow direction of the medium is not restricted;
4. Compared with the shut-off valve, when the gate valve is fully opened, the degree of erosion and erosion of the sealing surface by the fluid medium is low;
5. Simple structure, convenient installation and use, and good manufacturing technology;
6. The overall structure length of the valve is relatively short.
Disadvantages of gate valve:
1. The overall dimensions and opening height are relatively large, which requires a large installation space;
2. When the gate is opened and closed, the friction with the sealing surface of the valve seat is large, causing certain wear on the sealing surface;
3. Usually the gate valve has two sealing surfaces, which is difficult to process and grind, and it is quite troublesome to maintain;
4. It takes a long time to open and close.
Gate valves usually have more applications in the following areas:
1. Oil and natural gas pipelines.
2. Transportation pipeline and storage equipment of refined oil.
3. Wellhead equipment for oil and natural gas exploitation.
4. City gas transmission pipeline.
5. Tap water and sewage treatment projects.
TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D
Related news/knowledge:
The company is the world’s best does a flow control valve reduce pressure supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.