The article discusses an experimental study of the influence of the valve drive type on the dynamic loading and service life of valve seals of units. The results of research of the modes of closing of piston valves and bellows valves at different response speeds are presented. The differences in the amplitude characteristics of repeated impact, arising from the rapid return motion of the valves trim, in the piston and bellows versions of the valve are established. The influence of the operating mode on the service life in both versions of the valve design was assessed, and pressurized leakage tests were also carried out.