Pressure compensators for stabilizing the flow of water are disclosed including at least one flow orifice (10) passing through a pressure compensator body (1) and at least one flexible flow controller (2) which can at least partially block the orifice (10) to provide it with a predetermined flow area whereby the flow controller flexes and reduces the flow area at increased water pressures. Flow controllers are also disclosed for controlling the flow of water including a revolving body (5) for selectively opening and closing a number of flow openings (17) therethrough.