Mounting location
Preferably mount the valves at the return, as the temperature is lower there and the strain on the stem sealing gland is lower.
Dirt trap
Mount a dirt filter or dirt trap before the valve to ensure the proper functioning and long service life of the valve. Remove dirt, welding beads, etc. from the valves and pipes.
Cavitation
Cavitation can be avoided by limiting the pressure differential across the valve depending on the medium temperature and prepressure.