Techniques

Classification of Valves

Valve is a control part in the fluid delivery system, which controls the flow rate, pressure and direction of the fluid by changing the size of the flow area.

First, the classification of the valve:
There are many kinds of valves, and there are many kinds of classification methods: the following according to the purpose of classification, according to the pressure classification, according to the working temperature classification of the medium, according to the operation of the classification, the general classification method is introduced;
(一) Classification by use:
(1) truncation valve class: mainly used for truncation and conduction medium flow. This kind of valve includes: gate valve, globe valve, diaphragm valve, plug valve, ball valve, butterfly valve and so on.
(2) Regulating valve class: mainly used for regulating the flow of the medium, pressure, including regulating valve, throttle valve, pressure reducing valve, etc.
(3) Check valves: mainly used to prevent the backflow of media, including a variety of structures of the check valve.
(4) shunt valve class: used for distribution, separation or mixed media, including a variety of structures of the distribution valve, trap, etc.
(5) Safety valve: used for system overpressure safety protection, including various types of safety valves.
(二) Classification by pressure:
(1) Low pressure valve: nominal pressure PN≤1.6Mpa
(2) medium pressure valve: nominal pressure 1.6Mpa < PN≤6.4Mpa
(3) high pressure valve: nominal pressure 6.4Mpa < PN≤100 Mpa
(4) ultra-high pressure valve: nominal pressure PN≥100Mpa
(三) According to the working temperature of the medium classification:
(1) Room temperature valve: -40℃≤t≤120℃
(2) Medium temperature valve: 120℃≤t≤450℃
(3) High temperature valve: t≥450℃
(4) Low temperature valve: -100℃≤t≤-40℃
(5) ultra-low temperature valve: t≤-100℃
(四) Classification according to operation mode:
Divided into manual, pneumatic, hydraulic, electric and other valves.

(五) General classification:
This classification method is divided according to the working principle and purpose, and according to the structure, is the commonly used classification method, generally divided into: gate valve, globe valve, throttle valve, ball valve, butterfly valve, diaphragm valve, plug valve, check valve, safety valve, self-operated pressure regulating valve, trap, etc..