A spiral wound membrane module comprising: at least one membrane envelope wound about a permeate collection tube extending along an axis between an opposing first module end and second module end; and an end cap assembly located upon at least one of said module ends (30, 30'), wherein the end cap assembly comprises: an inner hub secured to the permeate collection tube and a concentric outer ring that defines an outer periphery of the end cap assembly, wherein the outer ring is connected to the inner hub by a plurality of radially extending supports separated by apertures that provide a fluid access pathway with the module; wherein the spiral wound membrane module is characterized by: the end cap assembly comprising a connecting conduit defining a fluid passageway extending radially inward from a first conduit end located at the outer periphery of the outer ring to a second conduit end located within the outer ring, and a differential pressure sensor connected to the fluid passageway of the connecting conduit and further wherein the end cap assembly includes an annular groove located on the outer periphery of the outer ring, a brine seal located within the annular groove, and wherein the first end of the connecting conduit is axially positioned between the brine seal and the opposite end of the module. at least one membrane envelope wound about a permeate collection tube extending along an axis between an opposing first module end and second module end; and an end cap assembly located upon at least one of said module ends (30, 30'), wherein the end cap assembly comprises: an inner hub secured to the permeate collection tube and a concentric outer ring that defines an outer periphery of the end cap assembly, wherein the outer ring is connected to the inner hub by a plurality of radially extending supports separated by apertures that provide a fluid access pathway with the module; wherein the spiral wound membrane module is characterized by: the end cap assembly comprising a connecting conduit defining a fluid passageway extending radially inward from a first conduit end located at the outer periphery of the outer ring to a second conduit end located within the outer ring, and a differential pressure sensor connected to the fluid passageway of the connecting conduit and further wherein the end cap assembly includes an annular groove located on the outer periphery of the outer ring, a brine seal located within the annular groove, and wherein the first end of the connecting conduit is axially positioned between the brine seal and the opposite end of the module. the end cap assembly comprising a connecting conduit defining a fluid passageway extending radially inward from a first conduit end located at the outer periphery of the outer ring to a second conduit end located within the outer ring, and a differential pressure sensor connected to the fluid passageway of the connecting conduit and further wherein the end cap assembly includes an annular groove located on the outer periphery of the outer ring, a brine seal located within the annular groove, and wherein the first end of the connecting conduit is axially positioned between the brine seal and the opposite end of the module.