Kombi-3-Plus blue, for return flow, gunmetal housing. General draining by means of adapter via the bonnet, subsequent differential pressure control possible by means of diaphragm regulator mounted on the bonnet (up to and including DN 40), no attachments to the valve body. Visible presetting display with concealed presetting ring, high accuracy due to individual adjustment. Maintenance-free spindle sealing due to double O-ring, PTFE seat sealing. DN 10 - 20 Universal connection with socket thread to DIN 2999 (ISO 7) for threaded pipe or for Cu and precision steel pipe 10 - 22 mm using clamping ring and pressure screw. DN 25 - 80 Connection with socket thread to DIN 2999 (ISO 7) for threaded pipe. For pH value from 8 - 9.5.