Conclusion
Industrial valves

For general applications, industrial valves will continue to evolve towards quarter-turn actuated valves, i.e. :

• to ball valves for small sizes (DN = nominal diameter < 80 mm) ;

• to butterfly valves for larger sizes : DN > 65 mm.

This outlook is due to :

• the ease with which these taps can be controlled (both automatically and manually);

• their sealing performance (100% leaktight) and flow performance (low or very low head losses);

• flexible pipe connections (3-piece ball valve, etc.);

• the small size of butterfly valves and the possibility of installing them between flanges (wafer...);

For more demanding applications, the evolution will surely continue with the use of higher-performance modified graphites (currently -200 to +500°C) and with...