How to select the valve
Posted by Bundor valve
Gate valve selection
In general, gate valves should be preferred.Gate valve in addition to steam, oil products and other media, also suitable for containing granular solid and viscosity of medium, and suitable for vent and low vacuum system of the valve.For medium with solid particles, one or two purge holes shall be provided on the gate valve body.For low temperature medium, special low temperature gate valve should be used.
Globe valve selection
Globe valves are suitable for pipelines with lax requirements for fluid resistance and for steam pipelines with DN < 200mm.There is flow regulation or pressure regulation, but the regulation accuracy requirements are not high, and the diameter of the pipeline is relatively small, it is appropriate to choose the globe valve;For highly toxic media, should choose bellows sealed globe valve;However, the globe valve should not be used for the medium with high viscosity and the medium containing particles that are easy to precipitate, and should not be used for the vent valve and the valve of the low vacuum system.
Ball valve selection
Ball valve is suitable for low temperature, high pressure, high viscosity medium.Most ball valves can be used with suspended solid particles in the medium, according to the material requirements of the seal can also be used in powder and granular media;The full-channel ball valve is not suitable for flow regulation, but it is suitable for the occasions requiring quick opening and closing, which is convenient for emergency cutting off.Usually in strict sealing performance, wear, shrink mouth channel, quick opening and closing action, high pressure cut-off (big pressure difference), low noise, gasification phenomenon, small operating torque, small fluid resistance of the pipeline, recommended use of ball valve;Ball valve is suitable for light construction, low pressure cut-off, corrosive medium.
Butterfly valve selection
Butterfly valve is suitable for the occasions with large diameter (such as DN > 600mm), short structure length, as well as rapid flow regulation and opening and closing requirements. It is generally used for water, oil, compressed air and other media with temperature ≤80℃ and pressure ≤ 1.0mpa.Butterfly valves are suitable for pipeline systems where pressure loss is not strictly required due to their large pressure loss relative to gate valves and ball valves.
Check valve selection
Check valve is generally suitable for clean medium, should not be used in the medium containing solid particles and larger viscosity.When DN≤40mm, it is advisable to adopt lifting check valve (only allowed to be installed on horizontal pipe);When DN = 50 ~ 400mm, swing lifting check valve should be adopted (it can be installed on both horizontal and vertical pipelines. If it is installed on vertical pipelines, the flow direction of media should be from bottom to top).Buffer check valve should be used when DN≥450mm;When DN = 100 ~ 400mm, sandwiched check valves can also be used;Swing check valve can be made into a very high working pressure, PN can reach 42MPa, according to the shell and seal material can be applied to any working medium and any working temperature range.