【Q&A Question 139】2018.05.19

Blow from top to bottom; blowing towards the pipeline side is strictly prohibited

1. Do not allow overpressure or pressure buildup. 2. Hydrogen-related systems must not be purged with water. 3. Fresh water and circulating water should be used for purging fresh water systems, while other utility systems should be purged using their respective media. 4. Purge the main lines first, followed by the branch lines; long pipes should be purged in segments. 5. Equipment can only be introduced after the pipelines have been thoroughly purged. 6. Pumps connected via bypass lines are not included in the purging process. 7. When water is introduced into the tower, both the upper vent and lower drain valves must be opened; purging can be carried out in a radial pattern from the tower to the surrounding pipelines. 8. All types of instruments and control valves must be removed, and they can be reinstalled only after thorough purging

Scan the heavy oil line first, then the light oil line

①Scan the heavy oil pipeline first, then the light oil pipeline. ②The heat exchanger should first be purged through the main line, and then through the secondary line. ③The cooler first shuts off the water supply and vents the water behind the inlet valve to drain all remaining water, before using steam to clean the lines. ④The control valve first sweeps the bypass line, then the main line of the control valve. ⑤The three-way merge valve moves repeatedly during cleaning. ⑥The gasoline and condensed oil systems should first be flushed with water to remove all the oil, and then purged with steam. ⑦Scanning is performed using the pressure-holding scanning method. ⑧After the fractional sweeping is complete, the pipelines and the oil remaining in the equipment should be rinsed with hot water at 80°C. After draining the oil, drain the water completely before proceeding with the distillation tower. ⑨Do not pour oil on the ground. ⑩When draining oil into the oily wastewater system, it must be rinsed with hot water to prevent the oily wastewater drains from being clogged by wax oil.

Answer: ① Sweep the heavy oil pipeline first, then the light oil pipeline. ②The heat exchanger should first be purged through the main line, and then through the secondary line. ③The cooler first shuts off the water supply and vents the water behind the inlet valve to drain all remaining water, before using steam to clean the lines. ④The control valve first sweeps the bypass line, then the main line of the control valve. ⑤The three-way merge valve moves repeatedly during cleaning. ⑥The gasoline and condensed oil systems should first be flushed with water to remove all the oil, and then purged with steam. ⑦Scanning is performed using the pressure-holding scanning method. ⑧After the fractional sweeping is complete, the pipelines and the oil remaining in the equipment should be rinsed with hot water at 80°C. After draining the oil, drain the water completely before proceeding with the distillation tower. ⑨Do not pour oil on the ground. ⑩When draining oil into the oily wastewater system, it must be rinsed with hot water to prevent the oily wastewater drains from being clogged by wax oil.

The principle for shutting down operations to clean the pipelines is: (1) Organize the cleaning work properly before shutting down, assigning each pipeline to a specific person. (2) Ensure proper wiring connections to prevent cross-wiring, injuries, or equipment failures. (3) Unified command should be exercised during line cleaning to ensure that the heavy oil pipeline has sufficient steam pressure, thus guaranteeing the effectiveness of the cleaning process. (4) Before introducing steam for scanning, the steam condensate must be completely drained, and steam should be introduced slowly to prevent water hammer. (5) In the sweeping step, heavy oils and oils that are prone to solidification are processed first, followed by light oils and oils that are not prone to solidification. (6) Pressure must be maintained during line cleaning; for heavy crude oils, pressure needs to be kept constant repeatedly in order to achieve a good cleaning effect. (7) Before cleaning the lines, all meters must be bypassed by using alternate routes; steam must not pass through these meters. (8) During line cleaning, all connected lines, main and auxiliary lines, spare lines, dead ends, and other pipelines, as well as control valves, must be thoroughly cleaned; no dead corners are allowed to remain. (9) It is strictly prohibited to vent oil vapors at various low points during the line cleaning process; these vents can only be used to check the progress of cleaning, and they must be closed promptly after inspection. (10) After the line cleaning is completed, the cleaning valve should be closed promptly, and the steam and condensate inside the equipment and pipelines must be completely drained. Records should be kept for the shutdown and line cleaning. Detailed records should be kept of factors such as steam supply, steam cut-off time, and operator names, to ensure clear accountability.

1. Do not allow overpressure or pressure buildup. 2. Hydrogen-related systems must not be purged with water. 3. Fresh water and circulating water should be used for purging fresh water systems, while other utility systems should be purged using their respective media. 4. Purge the main lines first, followed by the branch lines; long pipes should be purged in segments. 5. Equipment can only be introduced after the pipelines have been thoroughly purged. 6. Pumps connected via bypass lines are not included in the purging process. 7. When water is introduced into the tower, both the upper vent and lower drain valves must be opened; purging can be carried out in a radial pattern from the tower to the surrounding pipelines. 8. All types of instruments and control valves must be removed, and they can be reinstalled only after thorough purging

1. No overpressure, no pressure buildup； 2. The hydrogen-containing system cannot be purged with water ； 3. Fresh water is used for purging fresh water and circulating water, while other utility systems are purged with their respective media ； 4. Purge the main pipeline first and then the branch pipelines, in segments for long pipes ； 5. Purge the pipeline thoroughly before introducing it into the equipment ； 6. The cross-connected pumps are not involved in the purging process ； 7. When water is introduced into the tower, both the upper vent and the lower drain should be opened, allowing the tower to purge the pipelines surrounding it in a radial manner ； 8. Remove all types of instruments and control valves; they can be put back into use only after thorough purging.

1. No overpressure, no pressure buildup； 2. The hydrogen-containing system cannot be purged with water ； 3. Fresh water is used for purging fresh water and circulating water, while other utility systems are purged with their respective media ； 4. Purge the main pipeline first and then the branch pipelines, in segments for long pipes ； 5. Purge the pipeline thoroughly before introducing it into the equipment ； 6. The cross-connected pumps are not involved in the purging process ； 7. When water is introduced into the tower, both the upper vent and the lower drain should be opened, allowing the tower to purge the pipelines surrounding it in a radial manner ； 8. Remove all types of instruments and control valves; they can be put back into use only after thorough purging.

①Scan the heavy oil pipeline first, then the light oil pipeline. ②The heat exchanger should first be purged through the main line, and then through the secondary line. ③The cooler first shuts off the water supply and vents the water behind the inlet valve to drain all remaining water, before using steam to clean the lines. ④The control valve first sweeps the bypass line, then the main line of the control valve. ⑤The three-way merge valve moves repeatedly during cleaning. ⑥The gasoline and condensed oil systems should first be flushed with water to remove all the oil, and then purged with steam. ⑦Scanning is performed using the pressure-holding scanning method. ⑧After the fractional sweeping is complete, the pipelines and the oil remaining in the equipment should be rinsed with hot water at 80°C. After draining the oil, drain the water completely before proceeding with the distillation tower. ⑨Do not pour oil on the ground. ⑩When draining oil into the oily wastewater system, it must be rinsed with hot water to prevent the oily wastewater drains from being clogged by wax oil.