Large diameter lsaw steel pipe hydrostatic testing machine during the pressure test, the first sealing means by the end of the test straight seam steel pipe sealed at both ends and low-pressure water injection in the exhaust pipe filling process air through the exhaust valve, in after the water is full of low-pressure, high-pressure water injection device through the booster is to pressurize the inner tube until the required test pressure. After reaching a predetermined test pressure predetermined dwell time, if the straight seam steel pipe leak, deformation phenomena in the pressure test is carried out relief. Then open the end seals, low-pressure water discharge, straight seam steel pipe to be tested to check for visual inspection station for suspicious penetration. According to the standard pressure for pressure testing process curve automatic recording device for recording.
Pressure steps:
1. The hydrostatic pressure test pressure Longitudinal working pressure and test pressure of not less than 0.80MPa; Longitudinal such as work pressure is less than 0.8MPa, the hydrostatic test pressure selection 0.8MPa. Pressure test pressure test may not be replaced;
2. Longitudinal not respond after filling water filling exposed connection points (including the Longitudinal and Longitudinal attachment joints), it was discovered leakage should be excluded;
3. Longitudinal pressure test length of not more than 1000m. A fitting intermediate pipe section, hydrostatic testing segment length of not more than 500m, the system has different material Longitudinal pressure test should be carried out separately.
4. When the pressure test pipe ends should be solid and reliable inspection, pressure test, non-support facilities loose chipping off, the valve may not be used as the sealing plate.
5. The pressure should be used mechanical devices with metering device, and accuracy not less than 1.5 (the maximum permissible error does not exceed 1.5% of full scale), scale range should be 1.3 to 1.5 times the test pressure, dial diameter not less than 150mm.
