Chemical valves are a kind of important accessories used to control fluid in industrial pipelines. Faced with complicated industrial systems and categories of valves, choosing suitable valves for pipe systems should know about performances of valves, mastering procedures or basis for choosing valves and following the principles of choosing valves for petroleum or chemical industry. 

 

Chemical valves not only have wide range of application, but also have large usage amount. Without doubt, requirements for chemical valves are higher than that for common valves. Media for which chemical are used have strong corrosion. Environments existing in chlorine alkali industry or large petrochemical enterprises have high temperature, high pressure, strong corrosion and abrasion, large temperature or pressure difference. Due to valves faced with high risks, choosing and usage should follow chemical standard strictly. 

 

Principles for choosing chemical valves

Valves whose passage way is straight are generally chosen in chemical industry. Valves having low fluid resistance are used for cutting off or opening media. Valves apt to regulated flow are used to control flow. Plug valves and ball valves are suitable for being used for reversing and shunt. Valves whose disc slide along sealing face with wiping performance are the most suitable for media having suspended particles. Chemical valves in common use include ball valves, gate valves, globe valves, safety valves, plug valves and check valves.

 

Media contain chemical substances, including various categories of acid and alkali corrosive media. For common media, 304 stainless steel material is used as raw materials of sealing materials. Corrosive fluids combining various kinds of chemical substances choose alloy steel or tefulong.

 

Functions of chemical valves

On-off: cutting off or connecting media inside pipes;

Regulation: regulating flow and flow velocity inside pipes;

Throttling: resulting in media producing large pressure drop when flowing through valves.