The use of shut-off and control valves is necessary in the operation of pipeline systems. They differ in principle of operation, marking, dimensions and technical characteristics. 

The main purpose is to control the operating flow. The valves are used to control (stop, redirect, regulate pressure) flow of liquids (steam) in pipelines. Natural gas, machine oil, petrol, fuel oil, petroleum, chemicals, fresh water and seawater are the service fluids.

Shut-off and control valves have other functions:

• separating mediums in different states 
• protection of the system from emergencies 
• distribution or mixing of substances 
• backflow prevention

The main parameters of the equipment are the mechanical characteristics, chemical composition, durability and suitability for use in the required temperature range. Valves have a service life limit. They are subject to strict tests at the production stage.