A fluid system (300) may comprise a fluid passage (310) comprising a passage inlet (302) and a passage outlet (309), through which fluid may flow by entering the passage inlet (302) as an inlet flow (303) and exiting the passage outlet (309) as an outlet flow (308); a bypass valve (350; 400) comprising a bypass inlet (348; 448) and a bypass outlet (352; 452), the bypass inlet (348; 448) being in fluid communication with the passage inlet (302), wherein the bypass valve (350; 400) further comprises a piston (410) coupled to a spring (415); and a position sensor (440) coupled to the bypass valve (350; 400) and configured to detect a position of the piston (410) in the bypass valve (350; 400). The spring (415) may retain the piston (410) in a rest position (411), and the spring (415) and the piston (410) may be configured to block the fluid from passing through the bypass outlet (352; 452) in response to the inlet flow exerting a pressure below a bypass pressure threshold.