There are many types of valves and their range of use is also wide. If used improperly, there may be "running, emitting, dripping, and leaking" phenomena, with mild cases affecting production and severe cases causing accidents. So understanding and correctly using valves is a very important issue. There are many types of valves used in heating systems. For example, gate valves, globe valves, ball valves, butterfly valves, check valves, safety valves, regulating valves, balance valves, self-operated balance valves, and so on. 1. Gate valve, is a widely used type of valve. The sealing surface of the gate and the valve seat are highly smooth, flat, and consistent, and processed into a very close fitting and tight sealing pair. The gate plate conducts and shuts off the medium through the upward and downward pressure of the valve stem. It plays a shut-off role in the pipeline. 2. Globe valves are also widely used valves. Its working principle is similar to that of a gate valve, except that the closing part (valve disc) moves along the centerline of the valve seat. It plays a shut-off role in the pipeline and can also roughly adjust the flow rate. 3. Compared to gate and globe valves, ball valves are a new type of valve that is gradually being widely adopted. The valve core is a ball with a through cavity, which is controlled by the valve stem to rotate 90 ° to make the valve unobstructed or blocked. It plays a shut-off role in the pipeline. 4. Butterfly valves are currently the most widely used and diverse valve in heating systems. The valve disc is a disc that rotates through the valve stem and rotates at 90 ℃ within the valve seat range to achieve valve opening and closing. It plays a shut-off role in the pipeline. It can also adjust the flow rate. 5. Check valves are also known as single flow valves. It is a commonly used auxiliary valve. It is a valve that automatically opens and closes based on the force of the fluid itself and the weight of the valve disc. As the name suggests, its function is to prevent media backflow. Usually installed at the outlet of the water pump to prevent damage caused by water hammer. 6. The regulating valve is also called a control valve. It is a commonly used valve in the secondary network of heating systems. Its appearance and structure are similar to that of a shut-off valve, but the sealing pair is different. The valve disc and seat of the regulating valve are similar to the cork and mouth of a warm water bottle, and the flow rate is adjusted by changing the flow area through the movement of the valve disc. There is a ruler on the valve shaft indicating the corresponding flow rate. 7. Improved balance valve control valve. The flow channel adopts a direct current type, and the valve seat is changed to polytetrafluoroethylene. It overcomes the disadvantage of large flow resistance, makes the sealing more reasonable, and also has a cut-off function. 8. Self operated balance valve, also known as flow control valve. The...

The Numerical Control Multi-Pass Valve plays a crucial role in automating well selection and metering within oilfield metering stations. It replaces multiple metering pipe manifolds and electrically actuated three-way valve assemblies, streamlining well selection. Operated through control system automation or manual actuation, it enables automatic well switching, offering benefits like a compact footprint, streamlined operation, unmanned capability, and simplified installation. It can also be customized for specific needs, making it ideal for modernizing aging oil and gas metering stations on offshore platforms, artificial islands, and remote onshore areas. Features 1. Media Versatility: The valve handles various mediums, including light crude, heavy crude, oil-contaminated water, and clear water. 2. Simplified Operation: Streamlined control through a single multi-pass valve eliminates complex adjustments. 3. Cost-Effective: Fewer control units lead to investment savings of 20% to 30% compared to conventional systems. 4. High Sealing Performance: Self-compensating sealing and snug integration ensure zero leakage, supported by manual adjustments for maintenance. 5. Precision Engineering: Advanced positioning technologies enable near error-free well selection. 6. Durability and Efficiency: The hard-faced alloy sealing surface resists erosion, scaling, and extends service life. 7. Optimal Pressure Management: The system maintains a maximum pressure loss below 0.025 MPa.

According to the different structures of butterfly valves, we distinguish four types of butterfly valves: concentric butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves and triple eccentric butterfly valves. Concentric butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves and triple eccentric butterfly valves actually reflect a process of opening and closing with less and less effort and less and less wear on the sealing surface. By setting the position of the rotating shaft of the butterfly valve wedge, the sealing and opening states of the butterfly valve can be changed. Under the same conditions, the torque of the valve is greater than that of each opening. When the valve is opened, the rotation angle required for the valve plate to separate from the seal is smaller than the other. The structural feature of the concentric butterfly valve is that the shaft center of the valve stem, the center of the butterfly plate and the center of the valve body are at the same position. Generally, if concentric butterfly valves can be used, they should be used as much as possible. Because the concentric butterfly valve does not require high sealing performance in terms of structure or operation, it is a conventional product. To overcome squeezing, scraping, and ensure sealing performance, the valve seat of the concentric butterfly valve is basically made of elastic materials such as rubber or polytetrafluoroethylene, which is a soft sealing butterfly valve. This limits the use of concentric butterfly valves to temperature. In order to solve the squeezing problem between the butterfly plate and valve seat of the concentric butterfly valve, a single eccentric butterfly valve has also been produced. Its structural feature is that the axis of the valve stem deviates from the center of the butterfly plate. Double eccentric butterfly valves are the most widely used. Its structural feature is that the valve stem axis deviates from both the center of the butterfly plate and the center of the valve body, thus it is called a double eccentric butterfly valve. Many double eccentric butterfly valves are line sealed, causing friction between the butterfly plate and the valve seat when the sealing surface is closed, resulting in excellent sealing effect. It has the characteristics of small area and high pressure. After the valve is opened, the butterfly plate can quickly detach from the valve seat, greatly eliminating unnecessary excessive compression and scraping between the butterfly plate and the valve seat, reducing the opening resistance distance, reducing wear, and improving the service life of the valve seat. The triple eccentric butterfly valve has undergone a third eccentricity on the basis of the double eccentric butterfly valve, and the shape of the sealing pair is not a straight cone, but an inclined cone. It is mostly short distance force and surface sealing. The stem shaft of a three eccentri...

The sealing surface of the valve is a vulnerable component of the valve due to frequent corrosion, erosion, and wear from the medium. Automatic valves such as pneumatic ball valves and electric butterfly valves have frequent and fast opening and closing speeds, and the quality of their sealing surfaces directly affects the service life of the valves. The basic requirement for valve sealing surface is to ensure safe and reliable sealing under specified working conditions. Therefore, the material of the valve sealing surface should have the following characteristics. 1. Good sealing performance. The sealing surface should be able to effectively prevent the leakage of the medium; 2. A certain strength. Under the action of medium pressure difference, the sealing surface should be able to withstand the sealing specific pressure value formed by it; 3. Corrosion resistance. The sealing surface should have strong corrosion resistance that is suitable for the design requirements under the long-term action of corrosive media and stress; 4. Ability to resist scratches. The valve sealing pairs are all dynamic seals, and there is friction between the sealing pairs during the opening and closing process; 5. Erosion resistance. The sealing surface should be able to resist the erosion of high-speed media and the collision of solid particles; 6. Good thermal stability. The sealing surface should have sufficient strength and antioxidant capacity at high temperatures; At low temperatures, it should have good resistance to cold brittleness; 7. Good processing performance. Easy to manufacture and maintain, the valve functions as a universal component, ensuring economic value.

Sealing gasket is a commonly used sealing spare part for machinery, equipment, etc. It is a material that plays a sealing role. Correct installation can ensure sealing performance and smooth operation of the equipment, otherwise it will damage the sealing gasket. Next, let's take a specific look at what to do. The correct installation of gaskets should be carried out when the flange connection structure or threaded connection structure, sealing surface, and gasket have been inspected without any doubt, and other valve components are intact and undamaged. 1. Before installing the gasket, apply a layer of graphite powder or lubricant mixed with engine oil (or water) to the sealing surface, gasket, thread, and rotating parts of the bolt and nut. The gasket and graphite should be kept clean. 2. The gasket should be installed on the sealing surface in a moderate and correct manner, without deviation, and should not extend into the valve chamber or rest on the shoulder. 3. Only one gasket is allowed to be installed, and it is not allowed to install two or more gaskets between the sealing surfaces to eliminate insufficient clearance between the two sealing surfaces. 4. The sealing of elliptical gaskets should ensure that the inner and outer rings of the gasket come into contact, and the two ends of the gasket should not come into contact with the bottom of the groove. 5. The installation of the O-ring should not only meet the design requirements for the ring and groove, but also have an appropriate amount of compression. On the premise of ensuring sealing, the smaller the compression deformation rate, the better, which can extend the service life of the O-ring. 6. Before installing the gasket, the valve should be in the open position to avoid affecting installation and damaging the valve components. When covering, it should be aligned with the position and should not be pushed or pulled into contact with the gasket to avoid displacement and scratches on the gasket. 7. The installation of gaskets for bolted or threaded connections should ensure that the gaskets are in a horizontal position (threaded gaskets with wrench positions should not be used with pipe wrenches). 8. Before tightening the gasket, it is necessary to have a clear understanding of the pressure, temperature, properties of the medium, and material characteristics of the gasket to determine the pre tightening force. The preload should be minimized as much as possible without leakage during pressure testing. 9. After tightening the gasket, it is necessary to ensure that there is a pre tightening gap between the connecting parts in case of gasket leakage. 10. When working at high temperatures, bolts will experience high-temperature creep, stress relaxation, and increased deformation, leading to leakage at the gasket and requiring hot tightening. On the contrary, under low temperature conditions, bolts will shrink and require cold loosening. 11. When liquid sealing gaskets are used for sealin...

Many people believe that both gate and globe valves have the function of cutting off media, so they are not different when used. In fact, there are certain differences between gate valves and globe valves in practical applications. Gate Valve and Structural Diagram Globe Valve and Structural Diagram 1. Having different structures. Gate valves are more complex in structure, higher in height, and larger in size than globe valves. Gate valves are shorter and higher in appearance than globe valves. Especially, opening the stem gate valve requires a higher height. If the installation position of the valve is limited, it is necessary to choose rising stem and non-rising stem gate valves and remind everyone to pay attention. 2. When fully open, it has different flow resistance. The flow resistance coefficient of ordinary gate valves is approximately 0.08~0.12. The pressure loss during the operation of the gate valve medium is small, and the fluid flow resistance is small. Gate valves are usually suitable for working conditions where frequent opening and closing are not required and the gate is kept fully open or closed. It is not suitable for adjustment and throttling. The resistance coefficient of a regular globe valve is about 3.5-4.5, and the opening and closing forces are very small. The flow resistance of the shut-off valve throughout its entire stroke is very high, and the required driving force or torque is also much greater. But it is very suitable for regulation and throttling. 3. The flow direction of the medium inside the valve body is different. Gate valves have the same effect when viewed from both sides. When installing a shut-off valve, the medium can enter from below and above the valve core. 4. The sealing surface of the gate valve has a certain degree of self-sealing ability. The valve core is in close contact with the sealing surface of the valve seat through medium pressure, achieving sealing performance and no leakage. The sealing surfaces of the shut-off valve only come into contact with each other when fully closed, and the relative sliding amount between the forcibly closed valve core and the sealing surface is very small, so the wear of the sealing surface is also very small. 5. The maintenance procedures are different. The maintenance of gate valves is not applicable to on-site pipelines, but the seat and disc of most globe valves can be replaced online without the need to remove the entire valve from the pipeline (when the valve is not under pressure). This is very suitable for situations where valves and pipelines are welded together. Gate and globe valves are both fully open and fully closed valves. When selecting valves in the application process, attention should be paid to the characteristics of the valves. Globe valves are usually used for small pipelines and better sealing performance. In steam systems and large diameter pipelines, gate valves with low fluid resistance are usually used.