Abstract: A pressure compensator for maintaining essentially constant flow rates in an IV system having a source of IV fluid and a controller. The compensator is connectable to the controller and has a housing with a flexible membrane extending transversely therein defining opposite control chambers. One control chamber communicates with the source of IV fluid and also connects the inlet of the flow controller. The second control chamber receives the regulated flow from the control valve. The second control chamber is generally conical or convex sloping to an outlet port which is connected to the tubing line leading to the patient. The outlet from the second chamber is smaller than the inlet to the second chamber and the diaphragm serves to control the flow to the patient compensating for pressure changes such as a change in fluid head. The configuration of the second chamber and the configuratoin of the outlet in the second chamber minimize air entrapment and provide greater flow capacity.