1. Classification by use and function a. Two-position v […]
1. Classification by use and function
a. Two-position valve: mainly used to close or connect the medium;
b. Regulating valve: mainly used for regulating the system. When selecting a valve, it is necessary to determine the flow characteristics of the regulating valve;
c. Diverter valve: used to distribute or mix media;
d. Shut-off valve: usually refers to a valve with a leakage rate of less than 1/100,000.
2. Classification by main parameters
1 Sort by pressure
(1) Vacuum valve: the working pressure is lower than the standard atmospheric pressure;
(2) Low pressure valve: nominal pressure PN≤1.6MPa;
(3) Medium pressure valve: PN2.5～6.4MPa;
(4) High pressure valve: PN10.0～80.0MPa, usually PN22, PN32;
(5) Ultra-high pressure valve: PN≥100MPa.
2 Classification by medium working temperature
(1) High temperature valve: t>450℃;
(2) Medium temperature valve: 220℃≤t≤450℃;
(3) Normal temperature valve: -40℃≤t≤220℃; ④Low temperature valve: -200℃≤t≤-40℃.
3. Commonly used classification
This classification method is divided according to principle, function and structure, and is currently the most commonly used domestic and international classification method. Generally divided into nine categories:
Straight stroke pneumatic control valve
(1) Single-seat regulating valve;
(2) Double seat regulating valve;
(3) Sleeve regulating valve;
(4) Angle regulating valve;
(5) Three-way regulating valve;
(6) Diaphragm valve;
(7) Butterfly valve;
(8) Ball valve;
(9) Eccentric rotary valve. The first six are straight strokes, and the last three are angular strokes.
These nine products are also the most basic products, also known as common products, basic products or standard products. Various special products and special products are improved and modified on the basis of these nine types of products.