This diaphragm is the pumping element inside the sprayer’s main pump. It flexes to draw liquid into the pump chamber and then expel it under pressure toward the spray boom. The diaphragm sits between the pump head and the drive mechanism; its flex cycle determines the flow rate and pressure consistency. A worn or ruptured diaphragm causes pressure loss, uneven spray patterns, and internal leakage that bypasses fluid back to the intake. The manufacturer machines this replacement to the same thickness and flex modulus as the original assembly, so it maintains the pump’s displacement without requiring shim adjustments. On reinstall, ensure the diaphragm is centered in the pump housing and that all fasteners are tightened evenly to the specified torque.