This diaphragm is the flexible membrane inside the air chamber of a sprayer pressure regulator or pulsation damper. It separates the air pre-charge from the liquid circuit, allowing the chamber to absorb pressure spikes and maintain a steady flow to the spray nozzles. A ruptured or stretched diaphragm causes the air charge to escape, leading to pressure fluctuations and uneven spray distribution. The manufacturer's material and contour match the original chamber geometry so the pre-charge holds at the specified pressure. On replacement, ensure the chamber halves are clean and the seal surfaces are undamaged before reassembly.