RLV-KDV is a Dynamic H-piece designed for radiators with integrated valves (valve radiators) in 2-pipe systems. RLV-KDV combines the following functions: Integrated differential pressure controller using membrane technology; Constant pressure over the radiator and valve in full and partial load; Self-balancing to optimal pressure conditions once the flow presetting on the integrated radiator-valve is done; Lockshield on supply and return; Filling and draining possibility (with fill and drain tap 003L0152) and Self sealing connection pieces to the radiator for G ½ internal thread and G ¾ external thread.