WATER SQUARE THERMOSTATIC SHOWER VALVE WITH 3 WAY DIVERTER Portrait. Recessed Slim Backplate Water pressure - HP1 This model features an integrated double check valve(DCV) which protects water supplies from contamination and backfill.. This product operates 3 outlets from a single diverter instead of two. It can operate a bath filler with an overhead shower and handset or a three shower outlet such as a wall handset and a dual functioning overhead shower.