When the separator in operation, in its role in the differential pressure across the separator to produce a vapor side deflection (butterfly). If the deflection becomes plastically deformed, indicating that the separator lack of rigidity. Measuring the separator bending value when overhaul, and measuring the deflection value of the separator. Measurement methods, usually dedicated long ruler on the inlet side of the separator, close to the fixed position of the upper and lower surfaces of the separator combination with the accuracy of 0.02mm above the cursor depth ruler or feeler, measuring the distance between long ruler and each plate surface.