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I. Preparations before pressure testing 1. When testing high-pressure instrument pipelines under pressure, warning signs should be placed to prevent unauthorized personnel from entering; 2. Before testing, verify according to the drawings whether the material and specifications used for the high-pressure pipelines are correct, and check whether the records of the welding wire used in these pipelines are accurate； 3. Before the test, inspect the high-pressure instrument pipelines to check whether the welded parts have been painted; if so, the paint should be removed. 4. The pressure gauge used for the test has been calibrated and is still within its calibration period, with an accuracy not lower than grade 1.5. The full-scale range of the gauge should be 1.5 to 2 times the maximum pressure to be measured. 5. Check that the high-pressure instrument pipelines are properly reinforced. 6. Open the main valve and the drain valve of the pipeline to flush it, check that there are no obstructions in the pipeline, then close the main valve to verify that the valve core is tightly closed, and finally close the drain valve. 7. Check that the connection between the pressure testing pipeline and the instrument pipeline is correct; testing with a transmitter installed is prohibited. II. Pressure Testing of High-Pressure Instrument Pipelines 1. The pressure testing of high-pressure instrument pipelines should be carried out together with the process pipelines as part of the strength tests. 2. Clean water should be used for hydraulic testing, with the test pressure being 1.5 times the design pressure. When the pipeline material is austenitic stainless steel, the chloride content in the water must not exceed 25 mg/L. The water should be drained immediately after the test. 3. During the test, the pressure should be increased gradually and slowly. When the pressure reaches 50% of the test pressure, if no abnormalities or leaks are detected, the pressure should be increased further in steps of 10% of the test pressure, with each step being held for 3 minutes, until the test pressure is reached. Maintain the pressure for 10 minutes, then reduce it to the design pressure; the duration of pressure maintenance should be determined based on the requirements of the leak detection process. 4. For detecting leaks in high-pressure instrument pipelines, soapy water should be used for testing. Once the location of the leak is identified, no repairs should be carried out while the pipeline is under pressure. After the defect is fixed, testing should be conducted again. 5. After the pressure test is successful, it is advisable to release pressure at the other end of the pipeline to check whether there are any blockages. Fill in the instrument pipeline pressure testing record in a timely manner.