[94] Circuit diagram for pressure-less pump recirculation
The part circuit diagram
shows a 2/2-way valve used as a by-pass valve to achieve
pressure-less pump recirculation; if the valve is actuated, the
pump no longer needs to operate against the preset system
pressure.
One application of this circuit is with 4/3-way valves which are closed in their mid-position in cases where, with the installation operational, it is desired to switch to pump recirculation (see also topic 116).