To avoid any possibility of medium backflow, it is essential to have check valves installed throughout the equipment, devices, and pipelines. These valves provide an effective barrier against the reverse flow of the medium and ensure the smooth operation of the system. Without them, the entire system could be at risk of contamination and malfunction, which could result in serious safety and operational issues. Therefore, it is crucial to prioritize the installation of check valves in any medium-carrying capacity.
The check valve is only advisable for applications with clean media. It is not recommended for use with highly viscous or solid-laden liquids.
It is recommended to utilize horizontal lift check valves for horizontal pipes with a 50mm nominal diameter.
The installation of a straight-through lift check valve is limited to horizontal pipelines. It is essential to consider the orientation of the pipeline when utilizing this type of valve.
When selecting a valve for the pump inlet pipeline, it's recommended to choose a bottom valve. This type of valve is typically installed on the vertical pipeline of the pump inlet, allowing the medium to flow from bottom to top. It's important to note that the bottom valve should only be utilized in this specific application. Proper valve selection is critical for ensuring optimal performance and efficiency of the pumping system.
According to the original text information, the lifting type of valve offers superior sealing performance and provides greater fluid resistance when compared to the swing type. It is recommended to install the horizontal type of valve on a pipeline that runs horizontally, whereas the vertical type should be installed on a pipeline that runs vertically.
The swing check valve can be installed on pipelines in various positions, whether horizontal, vertical, or inclined. However, if it is installed on a vertical pipeline, the medium's flow direction must be from bottom to top. The installation position for this valve is not limited and can be adapted to different pipelines as needed.
It is not advisable to create the swing check valve with a small diameter. However, it is possible to design it for high working pressure, with a maximum nominal pressure of 42MPa. In terms of size, it can also be made quite large, with a maximum nominal diameter exceeding 2000mm. Depending on the materials used for the shell and seal, it can be utilized for various types of working media and diverse temperature ranges, including water, steam, gas, corrosive media, oil, and medication. Additionally, it is capable of accommodating temperatures within the range of -196℃ to 800℃.
The swing check valve is suitable for situations with low pressure and large diameter, and it is also commonly used in limited installation occasions.
The butterfly check valve offers great installation flexibility as it can be mounted on any position, be it a horizontal pipeline or a vertical or inclined one. This means that it can be installed in a variety of environments and can suit different applications.
The diaphragm check valve is an excellent choice for pipelines that are prone to water hammer occurrences. Its design effectively eliminates the reverse flow of the medium, thereby addressing the water hammer issue. This type of valve is commonly used in low-pressure and normal-temperature pipelines, specifically in tap water applications. It is able to handle temperatures ranging between -12 to 120℃ and works well under a working pressure of less than 1.6MPa. However, what sets the diaphragm check valve apart is its ability to accommodate larger pipe diameters, with a maximum DN size exceeding 2000mm. Its versatility and performance make it a reliable option for various pipeline systems.
The large diameter-capable ball check valve is a great fit for lower pressure pipes. Its design is best suited for these types of pipelines, ensuring they function smoothly and efficiently.
The ball check valve's shell material is durable stainless steel, while the seal's hollow sphere is coated with polytetrafluoroethylene engineering plastic. This addition makes it suitable for use in pipelines containing general corrosive medium, and it can operate within a temperature range of -101 to 150 ℃. Its nominal pressure shouldn't exceed 4.0MPa, and its nominal pass range falls between DN200-DN1200.
The first step in choosing a check valve for incompressible fluids is to determine the necessary closing speed. Once this is established, the second step is to consider the available types of check valves that can meet the required closing speed. It is vital to select the right type of check valve that can perform optimally in your particular fluid system. Therefore, a thorough evaluation of all available options is essential to make an informed decision. Consideration should also be given to factors such as fluid flow rate, pressure, and temperature, as well as overall system design.
When selecting check valves for compressible fluids, it is possible to follow a similar approach as the one used for incompressible fluids. In cases where the flow range of the medium is extensive, employing check valves specifically designed for compressible fluids is advisable. However, if there is a need to rapidly stop and start the medium flow without any interruption, such as at the outlet of a compressor, it is more fitting to use a lift check valve.
To ensure proper functioning of the check valve, it is important to determine the appropriate size for the valve. The valve supplier should provide information regarding the selected size, so that the valve size can be identified when it is fully opened at a given flow rate. This data is critical for ensuring optimal performance of the valve. Thus, it is essential to obtain this information from the supplier to ensure that the valve is accurately sized for the specific application.
When selecting check valves below DN50mm for high and medium pressure applications, it is recommended to choose either vertical lift check valves or straight-through lift check valves. These types of check valves are suitable for effectively managing fluid flow in such conditions.