Help needed: Purging and replacement steps for the oil-pressure actuated programmable valve system in the rough purification and purification stages of pressure swing adsorption

The original poster had that unit designed by a certain company, or utilized the technology of a particular firm; they should provide you with the technical documentation, including the procedures for purging and replacing the pressure-driven programmable valve systems used in the crude removal and purification stages of the pressure swing adsorption process.

Purging plan for the pressure swing adsorption pipeline system: a. After all components of the system have been installed, it is necessary to purge the system. For general process and hydraulic pipelines, compressed air or compressed nitrogen can be used as the purging gas; steam can be used to purge water pipelines, while instrument air should be used to purge instrument pipelines. The purging gas pressure should generally be no less than 0.5 MPa, while the purging pressure for stainless steel hydraulic pipelines should be no less than 1.0 MPa. b. The purging sequence is generally to start with the main pipes and then the branch pipes, proceeding in sections. When encountering devices such as orifice plates, filters, check valves, throttle valves, and control valves, they must be removed. c. Each adsorption tower should be purged along with the piping system. To prevent damage to the sealing surfaces of the programmable valves during purging, it is advisable to use a burst-type purging method for the PSA section: burst disks or asbestos gaskets should be installed at the ends of the main pipes, the programmable valves of the tower to be purged should be opened, and compressed air should be introduced into the tower until the compressed air breaks through the asbestos gasket. Special attention should be paid to the fact that before purging a VPSA unit, it is necessary to inspect each adsorption tower. The key step is to remove the lower distributor from each tower and clean out all foreign objects from the lower end cap – such as welding slag, electrodes, soil, etc. – to prevent these objects from being blown out during the purging process and causing damage to the programmable valves or leading to safety incidents. In general, it is not allowed to operate the programmable valves before or during purging, in order to avoid damaging the sealing surfaces. d. During the purging process, use a hammer (a wooden hammer for stainless steel pipes) to continuously strike the pipe. e. Place a white cloth or a white target plate at the purge exhaust port; if the gas emitted contains no dust, rust, slag, water, or other contaminants for 5 consecutive minutes, the purge is considered successful. 4) Airtightness test of the piping system: a. An airtightness test should also be conducted after completing the strength test and purging of the piping system. b. All equipment, pipelines, and instruments in the system must be installed as per the design before the airtightness test of the entire installation can be carried out. The airtightness test pressure for the PSA valve rack area is 1.9 MPa, while the test pressure for the desorption gas pipeline is 0.2 MPa. The experimental gas should be a dry gas. c. After reaching the experimental pressure, it is necessary to inspect all pipe connections and welds using soapy water; if any leaks are found, the pressure must be reduced before continuing with the inspection. d. System pressure retention requirement: The pressure drop within 1 hour shall not exceed 0.5% of the system pressure.

Thank you. Could you explain in detail the switches, valves, and their sequence one by one?

You need to manually control the valves based on your process flow and actual conditions; there are no fixed requirements regarding which valve should be opened first and which one later.

Could any of the experts please send me a complete plan and steps for purging and replacement? It can be sent to my QQ email address: 1477688905@qq.com. I need it urgently; thank you!

The following is the plan we prepared when preparing the report; we basically followed this plan in practice, so it can serve as a reference: Purging of the hydraulic system 1. Before installation, each pipeline in the hydraulic system should be cleaned with acid to ensure there are no foreign objects or dust buildup. 2. After installation, use compressed air to blow out each pipe in the hydraulic system one by one. Following the flow path of the oil, the connections to devices such as the oil pump station’s tank, oil pump, solenoid valve station, hydraulic valve cylinders, and accumulators are disconnected one by one. Compressed air is used to blow out debris from each pipe, while a wooden hammer is used to knock loose any impurities on the inner walls of the pipes. 3. Add diesel and turn on the oil pump to clean the entire system. Finally, drain the diesel, and clean out the diesel, debris, and grease from the fuel tank, cylinders, hoses, and pipes. 4. Add anti-wear hydraulic oil, start the oil pump for a trial run, and observe the operation of each valve; address any issues that arise promptly. After the valves have been operating properly for 48 hours, drain the oil from the system for filtering, and clean the oil tank, cylinders, hoses, and pipes. 5. Finally, add anti-wear hydraulic oil, and the hydraulic system will enter a normal standby state; continue to monitor the operation of the valves during operation. Purging of the decarburization system: 1. Before purging, it is necessary to check that all equipment, pipelines, flanges, valves, instruments, safety devices, etc. are present, and that the flow path is unobstructed, to ensure compliance with production safety and process requirements. Before purging, remove the relevant pressure gauges from the system; first purge the pipelines and equipment connected to the pressure gauges, and then use the pressure stored in each tower to purge the pipelines in sections. 2. Prepare a wooden hammer, tin, white cloth, or white paint to check whether the cleaning is thorough. 3. The purging process must be halted only after it has been approved by the purging test team. Requirements for purging: 1. The overall purging process must ensure that rust, slag, and other debris are not introduced into the equipment, in order to prevent blockages of the drain valves and damage to the spools of the hydraulic control valves. Remove the blind plates or short pipes from each main pipe and install baffles. 2. Detailed records must be kept for cleaning each device and every pipe section. After cleaning the previous section, connect the flange and short pipe, then prepare to clean the next section. 3. Blow clean using compressed air as the medium. When cleaning, use a wooden hammer to strike the pipes and welds to ensure that there are no residues such as iron filings or slag. 4. In case of special circumstances or safety hazards during the purging process, the purging must be stopped. 5. Purging pressure: ≤0.6 MPa. Purging step: Purge the main pipeline ； 1. Start the oil pump and close all program-controlled valves and manual valves. 2. Use an air compressor to inflate Tower A and build up pressure, raising it to 0.3 Mpa–0.5 Mpa. 3. Blow out each main pipe, remove the blind flanges at both ends of each main pipe, and manually open the inlet valve, the product gas valve, and the pressure reduction valve of Tower A in sequence to blow out each main pipe. 4. Using the same method, pressurize the other towers to clean each main pipe thoroughly. When Tower J has been cleaned, install a blind flange at the western end of the main pipe and remove the blind flange at the eastern end, thereby carrying out a final thorough cleaning of all the main pipes. 5. After cleaning the main pipe is complete, install a blind flange on it. 6. Apply pressure to Tower A, and sequentially purge the branch pipes connected to each main pipe. When connecting each branch pipe to the equipment, the equipment flange should be removed; after cleaning is complete, the flange should be reinstalled. 7. The cleaning of each branch pipe must be thorough, with no dead corners left. 8. When cleaning each pipeline, use a wooden hammer to tap on areas such as welded pipe connections; pay special attention to tapping the welds to ensure that all slag, rust, and other debris are thoroughly removed. 9. After cleaning is complete, install the flanges and blind plates in all areas. Get ready for pressure testing.

Dear experts: I have a question regarding the PSA pressure swing adsorption role – what exactly does \"impurity overload\" mean in PSA? And how to prevent overload of impurities in the position? Our unit uses the PSA technology from Chengdu Tianli Company