Selection instructions of ball valves Ball valve […]
Selection instructions of ball valves
Ball valves are suitable for low temperature, high pressure, high viscosity media. Most ball valves can be used in media with suspended solid particles and can also be used in powdered and granular media depending on the material requirements of the seal.
The full-channel ball valve is not suitable for flow regulation, but it is suitable for occasions requiring quick opening and closing, which is convenient for the emergency cut-off of accidents. It is recommended to use ball valves in pipelines with strict sealing performance, wear, shrinkage passage, rapid opening and closing action, high-pressure cutoff (large differential pressure), low noise, gasification, low operating torque, and low fluid resistance.
Ball valve is suitable for light structure, low-pressure cut-off, corrosive medium; ball valve is also the most ideal valve for low temperature and deep cooling medium. For low-temperature medium piping system and device, low-temperature ball valve with bonnet should be used.
When the floating ball valve is selected, the valve seat material should bear the load of the ball and the working medium. The large-diameter ball valve needs a large force during operation. The ball valve with DN≥200mm should use the worm gear transmission form; the fixed ball valve is suitable for the larger diameter. And the occasion of high pressure; in addition, the ball valve used in the process of highly toxic materials and combustible medium pipelines shall have a fireproof and anti-static structure.
Selection instructions of check valves
Check valves are generally suitable for use in clean media and are not suitable for media containing solid particles and high viscosity. When ≤40mm, use the lifting check valve (only allowed to be installed on the horizontal pipe); when DN=50~400mm, use the swing-type lifting check valve (can be installed on both horizontal and vertical pipes, if installed in On a vertical pipe, the flow of the medium is from bottom to top).
When the DN≥450mm, the buffer type check valve is used; when the DN=100~400mm, the wafer type check valve can also be used; the swing type check valve can be made into a high working pressure, and the PN can reach 42MPa, according to The housing and seal materials are available in any working medium and any operating temperature range.
The medium is water, steam, gas, corrosive medium, oil, medicine, and the like. The media operating temperature range is between -196 and 800 °C.
Selection instructions of shut-off valves
The shut-off valve is suitable for pipelines that do not require strict fluid resistance, that is, pipelines or devices that do not consider pressure loss, and high-temperature and high-pressure media. They are suitable for medium pipes such as steam with DN<200mm.
The shut-off valve has flow regulation or pressure regulation, but the adjustment accuracy is not high. When the pipeline diameter is relatively small, it is suitable to use the shut-off valve or the throttle valve.
For highly toxic media, a bellows-sealed shut-off valve is used, but the shut-off valve should not be used for mediums with high viscosity and media containing particles, and should not be used as valves for venting valves and low vacuum systems.
Selection instructions of butterfly valve
The butterfly valve is suitable for occasions with large caliber (such as DN>600mm) and short structural length requirements, as well as need to adjust the flow rate and fast opening and closing requirements. It is generally used for water, oil and compression with temperature ≤80°C and pressure ≤1.0MPa. Medium such as air. Since the butterfly valve has a relatively large pressure loss relative to the gate valve and the ball valve, the butterfly valve is suitable for use in a piping system where pressure loss is not critical.