Service Valve and Service Valve with Tap Connector. Chrome-plated brass valves opened or closed by 1/4 turn mechanism, operated via screwdriver slot Can be rotated out-of-sight, to help avoid tampering Large thro' bore for maximum flow 15mm service valve used to isolate part of system to allow for repair or replacement 15mm x 1/2 in BSP service valve with tap connector used to connect 1/2 in tap to supply pipe