It is estimated that pertroleum pipeline account for 10%~30% of the whole project, and the cost of valves, the crirical components of valves accont for 30% of petroleum pipeline. So usage of valves has close relation with the safety of the whole project and also has great influence on economy of the whole pretroleum project.

 

Gate valves, globe valves, check valves, safety valves, ball valves and butterfly valves are commonly utilized in petroleum pipeline. Special valve may also be included. The most common used valves are gate vales, account for 80%. Globe valves account for 10%. Others are ball valves, butterfly valves, safety valves and check valves.

 

Carbon steel is the most common material which is used to make valves, accounting for 90%. Other materials include alloy steel and stainless steel. However the different sizes caused by technics need nonstandard valves whose sizees are customized.