1. Pressure Test
Hydraulic Pressure Test: Applicable to liquid media systems. The test pressure is 1.5 times the working pressure, and the pressure holding time should not be less than 30 minutes. Observe for leaks or pressure drops.
Pneumatic Pressure Test: Applicable to gas media systems. The test pressure is 1.15 times the working pressure. Overpressure operation is strictly prohibited and must be carried out in a safe and isolated environment.
2. Soap Water Leak Detection Method (Recommended)
Use a brush or sprayer to evenly apply soap water to the flange connection, bolt roots, and gasket edges.
Slowly increase the pressure to the test pressure and carefully observe whether continuous bubbles are produced:
Short-lived bubbles: May be residual air, which is normal.
Continuous bubbles: Indicates a leak point, which needs to be marked and depressurized before handling.
3. Other Leak Detection Methods
Leak Detection Fluid Detection: Using specialized leak detection fluids (such as halogen leak detectors), sensitivity is higher than soapy water, suitable for minute leaks.
Helium Gas Spectrometry Leak Detection: Used in high-precision, high-safety scenarios (such as vacuum systems, chemical plants), capable of detecting extremely small leaks.
4. Supplementary Inspection for High-Temperature Operations
For systems that heat up during operation (such as steam pipelines), hot-tightening should be performed after the equipment reaches operating temperature, and a sealing check should be performed again to compensate for the loss of pre-tightening force due to thermal expansion and contraction.
5. Appearance and Structural Auxiliary Judgment
Check whether the flange faces are completely fitted, without warping or gaps.
Nailed flanges should have slight indentations, indicating effective engagement and anti-loosening.
If deformed or cracked nuts or bolts are found, they must be replaced and reinstalled immediately.
