Valve selection should not begin with size and pressure alone. Chemical composition, concentration, temperature and the presence of solids can directly influence lining, sealing and structural choices.
The same medium may behave differently at different concentrations and temperatures. Complete service information and compatibility data are therefore important to an appropriate selection.
Operating mode also matters. Frequent throttling, rapid isolation and long-term shutoff place different demands on valve construction. A clear service definition is the first step toward dependable selection.