Pressure pipeline inspection

Just ask the pipeline inspection company. As for the price, generally there are people who know it; you can ask them as well. Of course, on that basis, it’s also possible to negotiate a good discount.

Requirements for regular inspection of pressure pipelines (for reference only). In accordance with regulations and standards such as the \"Regulations on the Safety Supervision of Special Equipment\", the \"Provisions on the Safety Management and Supervision of Pressure Pipelines\", and the \"Rules for Regular Inspection of In-service Industrial Pipelines\" (trial version), as well as relevant industry standards, the following requirements apply: The user unit shall prepare design documents (pipeline layout diagrams, process flow diagrams, etc.), installation documents (completion records of installation, schematic diagrams, etc.), quality certification documents for pipeline components, technical data such as operating parameters, operation records, start-up and shutdown records, records of measures taken to address potential pipeline hazards, records of pipeline renovation work, maintenance reports, records of pipeline failure repairs, as well as previous online inspection reports from within the inspection cycle and the report from the most recent comprehensive inspection. A detailed register of the pressure pipeline’s registration status shall also be provided for inspection by the inspectors. The user unit shall carry out the on-site preparations for a comprehensive inspection to ensure that the pipelines to be inspected are in an appropriate condition for testing ； Provide a safe inspection environment, carry out the auxiliary tasks necessary for inspections (such as removing insulation, setting up scaffolding, grinding and rust removal, arranging lifting equipment, supplying electricity, water, gas, etc.), and assist the inspection team in carrying out comprehensive inspections. The safety requirements for inspections shall meet the following criteria: First, any attached components or other objects that may affect a thorough inspection of the pipeline must be cleaned or removed in accordance with the inspection requirements ； II. Scaffolding, portable ladders and other facilities set up for inspection must be safe and sturdy to facilitate inspection and testing work ； III. Pressure pipelines operating under high or low temperature conditions should be cooled or heated slowly in accordance with the requirements of the operating procedures, to prevent damage ； IV. Before testing, it is necessary to cut off the power supply connected to the pipeline or adjacent equipment, remove the fuses, and place clear safety signs ； V. When on-site radiographic inspection is required, the irradiation area should be isolated and safety signs should be installed ； VI. During a comprehensive inspection, the following conditions must be met: (1) The medium inside the pipeline must be completely removed, all sources of liquid, gas, or steam must be isolated using blind flanges, and clear isolation markers must be installed ； (II) Pipelines transporting flammable, oxidizing, toxic, or asphyxiating media shall be purged, neutralized, disinfected, and cleaned. For pipelines transporting flammable media, it is strictly prohibited to use air for displacement ； (III) The power supply voltage of the lighting devices and tools used for inspection inside the pipeline shall comply with the provisions of the current **standard \"Safe Voltage\" GB3805 ； Equipment and instruments used for testing must be within their valid calibration period and must pass inspection and calibration before they can be used. Thickness measurement and surface inspection: During the inspection process, it is required to conduct random thickness measurements on elbows, tees, and areas where the diameter changes; the sampling ratio is shown in Table 1. On-site, it is required that the aforementioned pipe fittings be polished to the specified proportions. The polishing requirements are as follows: polish the area around the welds as well as a 50 mm area on each side; remove any paint or rust so that the metallic surface is exposed ； Grind an area of about 10 cm2 at the center of the outer bend of the elbow. Table 1 Sampling ratio for thickness inspection at elbows, tees, and diameter changes. Pipe grades: GC1, GC2, GC3. Sampling ratio for each type of fitting: ≥50%, ≥20%, ≥5%. Radiographic testing: Welded joints of pipes in grades GC1 and GC2 should generally be subject to ultrasonic or radiographic testing as sampling checks. For GC3-grade pipes, if no abnormalities are found, ultrasonic or radiographic testing of their weld joints is generally not carried out as a random inspection. Table 2: Sampling ratio for ultrasonic or radiographic inspection of pipeline weld joints
Pipeline grade | Ultrasonic or radiographic inspection ratio
GC1 | 15% of the number of weld joints, with a minimum of 2 joints
GC2 | 10% of the number of weld joints, with a minimum of 2 joints
Note: 1. For pipelines subject to significant temperature and pressure fluctuations as well as vibration, the sampling ratio should be twice the values stated in the table. 2. The sampling rate for heat-resistant steel pipes shall be twice the value stated in the table. 3. Full-length non-destructive testing is performed on the randomly selected welded joints. If defects at safety level 3 or 4 are found during random inspections, the inspection frequency should be increased; the extent of this increase is determined through consultation between the inspectors and the operating unit, taking into account the pipeline operation parameters and operational experience. Pressure test: Pipelines that have undergone comprehensive inspection should generally be subjected to a pressure test. The pressure test shall be carried out in accordance with the \"Code for Construction and Acceptance of Industrial Metal Piping Projects\" GB50235; in the formula for calculating the test pressure, the design pressure can be replaced by the maximum operating pressure. Pressure tests should generally use liquid as the testing medium. When the design pressure of the pipeline is less than or equal to 0.6 MPa, gas can also be used as the testing medium, but effective safety measures must be taken. Pressure testing of pipelines made of brittle materials must never be carried out using gas. Safety accessories: Safety valves, pressure gauges and other such accessories must meet the required standards for safe operation and be within their valid calibration period.

Requirements for regular inspection of pressure pipelines (for reference only). In accordance with regulations and standards such as the \"Regulations on the Safety Supervision of Special Equipment\", the \"Provisions on the Safety Management and Supervision of Pressure Pipelines\", and the \"Rules for Regular Inspection of In-service Industrial Pipelines\" (trial version), as well as relevant industry standards, the following requirements apply: The user unit shall prepare design documents (pipeline layout diagrams, process flow diagrams, etc.), installation documents (completion records of installation, schematic diagrams, etc.), quality certification documents for pipeline components, technical data such as operating parameters, operation records, start-up and shutdown records, records of measures taken to address potential pipeline hazards, records of pipeline renovation work, maintenance reports, records of pipeline failure repairs, as well as previous online inspection reports from within the inspection cycle and the report from the most recent comprehensive inspection. A detailed register of the pressure pipeline’s registration status shall also be provided for inspection by the inspectors. The user unit shall carry out the on-site preparations for a comprehensive inspection to ensure that the pipelines to be inspected are in an appropriate condition for testing ； Provide a safe inspection environment, carry out the auxiliary tasks necessary for inspections (such as removing insulation, setting up scaffolding, grinding and rust removal, arranging lifting equipment, supplying electricity, water, gas, etc.), and assist the inspection team in carrying out comprehensive inspections. The safety requirements for inspections shall meet the following criteria: First, any attached components or other objects that may affect a thorough inspection of the pipeline must be cleaned or removed in accordance with the inspection requirements ； II. Scaffolding, portable ladders and other facilities set up for inspection must be safe and sturdy to facilitate inspection and testing work ； III. Pressure pipelines operating under high or low temperature conditions should be cooled or heated slowly in accordance with the requirements of the operating procedures, to prevent damage ； IV. Before testing, it is necessary to cut off the power supply connected to the pipeline or adjacent equipment, remove the fuses, and place clear safety signs ； V. When on-site radiographic inspection is required, the irradiation area should be isolated and safety signs should be installed ； VI. During a comprehensive inspection, the following conditions must be met: (1) The medium inside the pipeline must be completely removed, all sources of liquid, gas, or steam must be isolated using blind flanges, and clear isolation markers must be installed ； (II) Pipelines transporting flammable, oxidizing, toxic, or asphyxiating media shall be purged, neutralized, disinfected, and cleaned. For pipelines transporting flammable media, it is strictly prohibited to use air for displacement ； (III) The power supply voltage of the lighting devices and tools used for inspection inside the pipeline shall comply with the provisions of the current **standard \"Safe Voltage\" GB3805 ； Equipment and instruments used for testing must be within their valid calibration period and must pass inspection and calibration before they can be used. Thickness measurement and surface inspection: During the inspection process, it is required to conduct random thickness measurements on elbows, tees, and areas where the diameter changes; the sampling ratio is shown in Table 1. On-site, it is required that the aforementioned pipe fittings be polished to the specified proportions. The polishing requirements are as follows: polish the area around the welds as well as a 50 mm area on each side; remove any paint or rust so that the metallic surface is exposed ； Grind an area of about 10 cm2 at the center of the outer bend of the elbow. Table 1 Sampling ratio for thickness inspection at elbows, tees, and diameter changes. Pipe grades: GC1, GC2, GC3. Sampling ratio for each type of fitting: ≥50%, ≥20%, ≥5%. Radiographic testing: Welded joints of pipes in grades GC1 and GC2 should generally be subject to ultrasonic or radiographic testing as sampling checks. For GC3-grade pipes, if no abnormalities are found, ultrasonic or radiographic testing of their weld joints is generally not carried out as a random inspection. Table 2: Sampling ratio for ultrasonic or radiographic inspection of pipeline weld joints
Pipeline grade | Ultrasonic or radiographic inspection ratio
GC1 | 15% of the number of weld joints, with a minimum of 2 joints
GC2 | 10% of the number of weld joints, with a minimum of 2 joints
Note: 1. For pipelines subject to significant temperature and pressure fluctuations as well as vibration, the sampling ratio should be twice the values stated in the table. 2. The sampling rate for heat-resistant steel pipes shall be twice the value stated in the table. 3. Full-length non-destructive testing is performed on the randomly selected welded joints. If defects at safety level 3 or 4 are found during random inspections, the inspection frequency should be increased; the extent of this increase is determined through consultation between the inspectors and the operating unit, taking into account the pipeline operation parameters and operational experience. Pressure test: Pipelines that have undergone comprehensive inspection should generally be subjected to a pressure test. The pressure test shall be carried out in accordance with the \"Code for Construction and Acceptance of Industrial Metal Piping Projects\" GB50235; in the formula for calculating the test pressure, the design pressure can be replaced by the maximum operating pressure. Pressure tests should generally use liquid as the testing medium. When the design pressure of the pipeline is less than or equal to 0.6 MPa, gas can also be used as the testing medium, but effective safety measures must be taken. Pressure testing of pipelines made of brittle materials must never be carried out using gas. Safety accessories: Safety valves, pressure gauges and other such accessories must meet the required standards for safe operation and be within their valid calibration period.

Find a qualified testing agency.

Just go to the special inspection agency. As for the price, it will be lower if you give them proper bribes, and higher otherwise; it depends on them