The manually operated connection with a step throttle is used to drain the bypass volume through a manually operated valve combination. This connection is recommended to protect the internal parts of the bypass under extreme operating conditions, for example at high differential pressure and frequent operation in the bypass range, as well as when filling and starting up the system.
The start-up trim (SUT) replaces the valve head when cleaning and starting up the system, thus protecting the internal parts of the bypass (optional, permanently open bypass outlet). The SUT can also be used as an alternative to the manually operated connection (see above).
The SDV pressure maintenance device avoids cavitation and evaporation in pipes. The functionality of the SDV corresponds to a variable throttle distance that depends on the volume flow.
The SRV attenuation valve is positioned on the SSV free-wheeling return valve and reduces pressure surges during frequent switching, for example in the case of descaling systems in steel mills.