Common Valve Selection Instructions

Feb. 15, 2020

1 Selection of gate valve

Globe valve supplier to share with you: In general, gate valves should be preferred. In addition to steam, oil and other media, the gate valve is also suitable for media containing granular solids and high viscosity, and suitable for venting and low vacuum systems. For media with solid particles, the gate valve body should have one or two purge holes. For low temperature media, special low temperature gate valves should be selected.

2 stop valve selection instructions

Globe valve is suitable for pipelines that do not have strict requirements on fluid resistance, that is, pipelines or devices that have little consideration for pressure loss, and high-temperature and high-pressure media.

Stop valves can be used for small valves, such as needle valves, instrument valves, sampling valves, and pressure gauge valves.

The stop valve has flow adjustment or pressure adjustment, but it does not require high adjustment accuracy, and the diameter of the pipeline is relatively small. Stop valves or throttle valves should be used.

For highly toxic media, a bellows-sealed globe valve should be used; however, globe valves should not be used for mediums with high viscosity and medium containing particles that are liable to settle, and should not be used as venting valves and valves for low vacuum systems.

3 ball valve selection instructions

Ball valves are suitable for low temperature, high pressure, and high viscosity media. Most ball valves can be used in media with suspended solid particles, and can also be used in powder and granular media depending on the material requirements of the seal.

Full-channel ball valve is not suitable for flow regulation, but it is suitable for occasions requiring fast opening and closing, which is convenient for emergency cut-off of accidents; usually in tight sealing performance, wear, necked passage, rapid opening and closing action, high pressure cutoff (large pressure difference) Ball valves are recommended for pipelines with low noise, gasification, low operating torque, and low fluid resistance.

O Type Ball Valve

O Type Ball Valve

O type ball valve is suitable for light structure, low pressure cut-off, and corrosive medium; ball valve is also the most ideal valve for low temperature and cryogenic medium. The piping system and device of low temperature medium should be selected with valve cover Cryogenic ball valve.

When selecting a floating ball valve, the seat material should bear the load of the ball and the working medium. Large-diameter ball valves require a large force during operation, DN & ge.

200mm ball valves should use worm gear transmission; fixed ball valves are suitable for larger calibers and higher pressures; in addition, ball valves used for highly toxic materials and flammable media pipelines should have fire and antistatic structures.

4 throttle selection

Throttle valve is suitable for occasions with low medium temperature and high pressure. It is suitable for parts where flow rate and pressure need to be adjusted. It is not suitable for medium with high viscosity and solid particles. It should not be used as a shut-off valve.

5 plug valve selection instructions

The plug valve is suitable for occasions requiring fast opening and closing. Generally, it is not suitable for steam and high temperature media, for low temperature and high viscosity media, and also for media with suspended particles.

6 butterfly valve selection instructions

Butterfly valves are suitable for large caliber (such as DN, 600mm) and short structure length requirements, as well as the need for flow regulation and quick opening and closing requirements, generally usaed for temperature ≤

80℃, pressure ≤1.0mpa water, oil, compressed air and other media;Due to the butterfly valve relative to the gate valve, ball valve pressure loss is relatively large, so the butterfly valve is suitable for the pressure loss requirements are not strict in the pipeline system.


Check valve selection instructions

Check valves are generally suitable for clean medium, not for medium containing solid particles and viscosity.When ≤40mm, shall use the lift check valve (only allowed to install on the horizontal pipe);When DN = 50 ~ 400mm, it is appropriate to use swing lift check valve (can be installed in both horizontal and vertical pipelines, if installed in the vertical pipeline, the flow of media from the bottom up);

When DN≥450mm, buffer type check valve should be used;When DN = 100 ~ 400mm, the pair check valve can also be used.Swing check valves can be made to work at very high pressure, PN can reach 42MPa, depending on the shell and seal material can be applied to any working medium and any operating temperature range.

Medium for water, steam, gas, corrosive media, oil, drugs and so on.The operating temperature range of the medium is -196 ~ 800℃.

Description of diaphragm valve selection

Diaphragm valve is suitable for operating temperature less than 200℃, pressure less than 1.0MPa oil, water, acid medium and containing suspended medium, not for organic solvents and strong oxidizer medium;

Weir diaphragm valve should be selected for abrasive granular medium, and the flow characteristics of weir diaphragm valve should be referred to.Viscous fluid, cement slurry and precipitating medium should choose straight diaphragm valve;Diaphragm valves should not be used for vacuum piping and vacuum equipment except for specific requirements.