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Purging Plan for the Instrument Air Compressor Station System 1. Basis for preparation………………………………………………………2 2. Purpose of air purging………………………………………………2 3. Conditions for air purging of the system…………………………………2 4. Principles and technical requirements for air purging…………………………………3 5. Purging of indoor pipeline and equipment systems……………………………………5 6. Purging plan for the instrument air main pipe………………………………………5 7. Purging plan for the plant air main pipe………………………………………5 8. Precautions………………………………………………………6 9. Pipeline purging record confirmation form………………………………………6 10. System purging diagram……………………………………………………6 1. Basis for preparation: GB50235-97 \"Code for Construction and Acceptance of Industrial Metal Piping Projects\". Design drawings and technical documents from the Sixth Design Institute of the Ministry of Chemical Industry. Air compressor station equipment manual. 2. Purpose of air purging The purpose of air purging is to use compressed air to remove any weld slag, debris, and other residues remaining from the installation of equipment pipes, thereby ensuring the safe operation of the system. 3. System air purging conditions 3.1 The work related to power supply, lighting, and instrument control systems, as well as the installation of pipelines and equipment and anti-corrosion and insulation measures, has all been completed. The site has been cleared, roads are accessible, and all conditions for use are met. 3.2 The construction unit completes the construction, and after joint inspection by all relevant units and departments, it is confirmed to be qualified. 3.3 Equipment such as air compressors is ready for operation; the factory’s air storage tanks and instrument air storage tanks have passed inspection and pressure testing, and have obtained usage permits; safety accessories such as safety valves have also passed calibration. 3.4 The “three inspections and four determinations” prior to commissioning shall be completed by the relevant units and departments, followed by corrective actions. 3.5 The operating procedures for the air compressor station, as well as the system commissioning and purging plans, have been approved. 3.6 Sinochem has the facilities for laboratory analysis. 3.7 The circulating water section is operating normally. 3.8 The individual test run of the oil-free screw compressor is completed. 3.9 Requirements for personnel participating in air purging 3.9.1 The participants should be familiar with the plan and have undergone several simulations. 3.9.2 Operators must have a thorough understanding of the process flow, equipment parameters, performance characteristics, control criteria, and operating procedures related to their position; they must possess the ability to operate independently and handle emergencies. Only after passing the relevant examinations and obtaining an operational certificate can they take up their posts. 3.9.3 All participants must undergo safety training and safety examinations as required, understand how to use safety protection equipment, and obtain a safety operation certificate. 3.10 The safety officer in charge and safety personnel must be on site to oversee safety matters. 3.11 Complete safety and labor protection equipment is available. 3.12 Good communication channels, with complete fire-fighting equipment available. 4. Principles and technical requirements for air purging 4.1 The purging sequence should follow the order of main pipes, branch pipes, and drain pipes; any dirt removed during purging must not enter the system. 4.2 Before purging, the stability of the pipe supports and hangers should be checked, and reinforcement should be carried out if necessary. 4.3 A no-entry zone should be established during purging. 4.4 After the pipeline has been purged successfully and returned to its normal state, no other operations that could affect the cleanliness inside the pipeline shall be carried out. 4.5 When resetting the pipelines, the construction unit shall, together with the user unit, conduct inspections, fill out the \"Purging Record for Equipment and Pipeline Systems\" in the specified format, and have it signed and approved by representatives from the construction unit, the supervision company, and the project owner. 4.6 The purging pressure shall not exceed the design pressure of the vessels and pipelines, and is generally required to be between 0.5 and 0.7 MPa. 4.7 During the air purging process, once it is visually confirmed that no smoke or dust is present in the exhaust gas, a white wooden target should be placed at the exhaust outlet for inspection; if there is no rust, dust, moisture, or other debris on the target within 5 minutes, it is considered acceptable. Otherwise, purging should continue until it meets the requirements. 4.8 No one shall stand at the blowing outlet to prevent the blown materials from causing injury; all blowing operations must be supervised by a designated person and recorded. 4.9 During purging, the construction unit shall use a wooden hammer to strike the pipes continuously, paying special attention to welds and dead corners, but must not damage the pipes until purging is successful. 4.10 Proper personal protective equipment must be used during purging, and safety operating procedures must be followed. When working at heights, make sure to wear a safety belt. 4.11 During the purging process, the upstream system must be qualified before proceeding to the downstream system. 4.12 During purging, the purge outlet (discharge outlet) must not be aligned with equipment openings, pipe openings, or electrical equipment; otherwise, the contractor shall install baffles. 4.14 Before starting each purging operation, the other pipelines in the system should be checked; the ends of those pipelines should be sealed or the valves should be closed. 4.15 The air compressor operates in automatic mode, with the bypass valve of PV7002 used to assist in controlling the pressure. 4.16 The construction unit shall organize personnel to carry out manual cleaning of D7001 and D7002. Confirm that the tank is clean and free of debris. 5 Purging of indoor pipeline and equipment systems 5.1 Purging of factory air pipelines and equipment 5.1.1 Remove the following pressure gauges respectively: pressure gauge PT7003, pressure gauge PG70004, pressure gauge PG70005, and the pressure tapping tube of pressure gauge PT7004; after repeated purging, reinstall them. 5.1.2 Remove the inlet check valve of factory air ball tank D-7002, replace it with a bypass, disconnect the inlet flange of D-7002, pry open the flange using a crowbar, and cover the inlet of D-7002 with a blind flange. 5.1.2 Open the inlet gate valve of D-7002 to purge the 4″-PA-A1B-70001 inlet pipe of D-7002, with the discharge occurring at the disconnected inlet flange of D7002; control this process using the inlet gate valve of D-7002, and repeat the purging several times. Monitor the pressure gauge PG70004 – the purge pressure should be between 0.5 and 0.7 MPa. Use a white target plate for inspection; it is considered satisfactory if there is no rust, dust, or other debris on the target plate within 5 minutes. Reintroduce the D-7002 imported flange upon approval. 5.1.3 Remove the air conditioning control valve HV7002, safety valve SV7002, and outlet flow meter FT7002, and replace them with bypass connections; also disconnect the short connection of the outlet flow meter FT7002. 5.1.4 Close the manual valve at the outlet of plant air receiver D7002, and open the inlet valve of D-7002 to purge the pipeline connected to D7002. The purge is carried out through the drain port, vent port, safety valve vent port of D-7002, as well as the short connection of flow meter FT7002. Control is exercised using the drain valve, vent valve, and safety valve cut-off valves; the process is repeated several times. Monitor pressure gauge PG70005 – the purge pressure should be between 0.5 and 0.7 MPa. Inspection is performed using a white target plate: it is considered successful if there is no rust, dust, or other debris on the target plate within 5 minutes. After passing the inspection, restore all facilities in the factory’s air system. 5.2 Purging of instrument air pipelines and equipment 5.2.1 Remove pressure gauges PT7001, pressure gauge PG70002, pressure gauge PT7002, and pressure gauge PG70003; after repeated purging, reinstall them. . 5.2.2 Disconnect the flange of the S-7001 inlet valve and install a blind plate; purge 4″-A -A1B-70002, and once it passes the inspection, reinstall the flange of the S-7001 inlet valve. Disconnect the flange of the Y-7002 inlet valve (tee) to use it as a blowdown port; open the S-7001 bypass valve to purge 4″-A -A1B-70006 and 4″-A -A1B-70004, controlling this process with the S-7001 bypass valve. Turn it on and off several times for purging, and monitor the pressure gauge PG70001 – the purge pressure should be between 0.5 and 0.7 MPa. Use a white target plate for inspection; if there is no rust, dust, or other debris on the plate within 5 minutes, the result is considered satisfactory. After passing the inspection, disconnect the flange of the Y-7002 outlet valve and short-circuit its inlet and outlet (the materials required for this short-circuiting are as follows: 2 meters of 3″ steel pipe, 2 flanges, and 2 elbows). S-7001 is put into use. 5.2.3 Disconnect the flange of the S-7002 inlet valve and install a blind plate; then purge the 4″-A -A1B-70005. Once this is complete, reattach the flange of the S-7002 inlet valve, remove the D-7001 inlet check valve, and cover the D-7001 inlet flange with a blind plate. 5.2.4 Open the S-7002 bypass valve to purge 4″-A -A1B-70007 and 4″-A -A1B-70001, with the exhaust flowing from the disconnected inlet flange of D-7001; the S-7002 bypass valve is used to control this process. Turn it on and off several times for purging, and monitor the pressure gauge PG70002 – the purge pressure should be between 0.5 and 0.7 MPa. Inspection using a white target plate shows that it is acceptable if there is no rust, dust, moisture, or other contaminants on the target plate within 5 minutes. After passing the inspection, restore the inlet check valve of the instrument air ball tank D-7001 and put S-7002 into operation. 5.2.5 Remove the D-7001 safety valve SV7001, the cooling air control valve HV7001, the outlet control valve HV7003, and the flow meter FT7001, and replace them with bypass connections. Remove the filter element of the outlet filter PS-7001. 5.2.6 Close the manual valve, vent valve, and safety valve shut-off valve at the outlet of D-7001, open the inlet valve of D-7001, and purge the pipeline of D-7001 by releasing gas from its drain port, vent port, and safety valve vent port respectively. Use the drain valve, vent valve, and safety valve shut-off valve of D-7001 to control this process, and repeat the purging several times. Monitor the pressure gauge PG70003; the purge pressure should be between 0.5 and 0.7 MPa. Check using a white target plate – if there is no rust, dust, moisture, or other contaminants on the target plate within 5 minutes, then the process is considered successful. After passing the inspection, restore all facilities in the instrument air system. 6 Purging Plan for the Instrument Air Main Pipe 6.1 The outlet valve D7001 is Valve No. 0, and it is the responsibility of the construction party to operate this valve. 6.2 Check other relevant instrument air pipelines; the ends of the pipelines should be blocked or the valves should be closed. 6.3 Remove the blind flange at the end of the 6″-IA-A3B-68001 pipeline to use it as Outlet No. 1; open Valve No. 0 and purge the 6″-IA-A3B-68001 and 2″-IA-A3B-68013 pipelines using a purge pressure of 0.50–0.65 Mpa. (When the pressure in D7001 is below 0.50 Mpa, close the outlet valve of D7001; once the pressure rises to 0.65 Mpa, reopen it.) After 12 hours, conduct a test by shooting at Outlet No. 1 – if there is no rust, dust, moisture, or other debris on the target within 5 minutes, the test is considered successful; otherwise, continue purging until the requirement is met. 6.4 After the 1# discharge outlet passes the target shooting test, close valve 0#, reset the 1# discharge outlet, and then sequentially disconnect the flanges in front of the main instrument air valves for the following work numbers: 633, 701–705, 708, 801–803, 442, 450, 615, 612, 222, 460A. Open valve 0#. The purging pressure should be 0.50–0.65 Mpa. Perform a test by directing the purge gas at a target; it is considered successful if no rust, dust, moisture, or other contaminants are present on the target within 5 minutes. If not, continue with the purging process until the requirements are met, after which reset the system. 6.5 After the testing of the work number associated with pipeline No. 1 is successful, close valve No. 0. Reset the discharge outlet corresponding to the work number of pipeline No. 1, then remove the end blind flange on 3″-IA-A3B-68004 to use it as discharge outlet No. 2. Open valve No. 0 and purge the pipelines 4″-IA-A3B-68006 and 3″-IA-A3B-68004. The purging pressure is 0.50–0.65 Mpa; (when the pressure at D7001 is below 0.50 Mpa, close the outlet valve of D7001, and once the pressure rises to 0.65 Mpa, reopen it). After 12 hours, perform a test by firing at the discharge port No. 2 – if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes, the result is considered satisfactory; otherwise, continue with the purging process until the requirements are met. 6.6 After the 2# discharge outlet passes the target testing, close valve 0#, reset the 2# discharge outlet, and then sequentially disconnect the flanges in front of the main instrument air valves for stations 191, 504A/B, 208A, 208, 241, and dimethyl ether. Open valve 0#. The purging pressure should be 0.50–0.65 Mpa. Perform a test by directing the purge gas at a target; it is considered successful if no rust, dust, moisture, or other contaminants are present on the target within 5 minutes. If not, continue with the purging process until the requirements are met, after which reset the system. 6.7 After the testing of the work number associated with pipeline No. 2 is successful, close valve No. 0. Reset the discharge outlet corresponding to the work number of pipeline No. 2, then disconnect the end blind flange of 2″-IA-A3B-68005 to use it as discharge outlet No. 3. After that, open valve No. 0 and purge the pipelines 2″-IA-A3B-68005 and 4″-IA-A3B-68006. The purging pressure should be 0.50–0.65 Mpa (when the pressure at D7001 is below 0.50 Mpa, close the outlet valve of D7001; once the pressure rises to 0.65 Mpa, open the outlet valve of D7001 again). After 12 hours, perform a test by shooting at the discharge port No. 3; if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes, it is considered satisfactory. Otherwise, continue with the purging process until the requirements are met. 6.8 After the 3# discharge port passes the target testing, close valve 0#, reset the 3# discharge port, and then sequentially disconnect the flanges 502, 274, and 211 in front of the main instrument air valves for the respective workstations. Open valve 0#. The purging pressure should be 0.50–0.65 Mpa. Perform a test by directing the purge gas at a target; it is considered successful if no rust, dust, moisture, or other contaminants are present on the target within 5 minutes. If not, continue with the purging process until the requirements are met, after which reset the system. 6.9 After the testing of the work number associated with pipeline No. 3 is successful, close valve No. 0. Reset the discharge outlet corresponding to pipeline No. 3, then disconnect the front flange of pipeline 5″-IA-A3B-93007 at V9306, as well as the front flange of pipeline 3″-IA-A3B-99001 at V9904 and the rear flange at V9905 (remove the S9901 filter element); use this as the discharge outlet for pipeline No. 4. After disconnection, open valve No. 0 and purge pipelines 5″-IA-A3B-93007 and 3″-IA-A3B-99001. The purging pressure should be 0.50–0.65 Mpa (when the pressure at D7001 is below 0.50 Mpa, close the outlet valve of D7001; once the pressure rises to 0.65 Mpa, open the outlet valve of D7001 again). After 12 hours, perform a test by firing at the discharge port No. 3; if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes, it is considered acceptable. Otherwise, continue with the purging process until the requirements are met before resuming normal operation. 7 Plant air main purging plan 7.1 The outlet valve of D7002 is a Type 0 valve, and the construction party is responsible for operating this valve. 7.2 Inspect the air pipelines in the relevant factory workstations; the ends of the pipelines should be sealed or the valves should be closed. 7.3 Remove the blind flange at the end of the 5″-PA-A1B-68003 pipeline to use it as outlet No. 1; open valve No. 0 and purge the 6″-PA-A1B-68001 and 5″-PA-A1B-68003 pipelines, with a purging pressure of 0.50–0.65 Mpa. (When the pressure at D7002 is below 0.50 MPa, close the outlet valve of D7002; once the pressure rises to 0.65 MPa, reopen that outlet valve.) A test is conducted by shooting at outlet No. 1; it is considered successful if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes. Otherwise, the cleaning process continues until the standard is met. 7.4 After the 1# discharge outlet passes the target testing, close valve 0#, reset the 1# discharge outlet, and then sequentially disconnect flanges 701, 702–705, 222, 460A, 801–802 in front of the main factory air valves for the respective workstations. Open valve 0#. The purging pressure should be 0.50–0.65 Mpa. Perform a test by directing the purge gas at a target; it is considered successful if no rust, dust, moisture, or other contaminants are present on the target within 5 minutes. If not, continue with the purging process until the requirements are met, after which reset the system. 7.5 After the testing of the work number associated with pipeline No. 1 is successful, close valve No. 0. Reset the discharge outlet corresponding to the work number of pipeline No. 1, then disconnect the end blind flange of 191 work number, 4″-PA-A1B-68004, using it as discharge outlet No. 2. After disconnection, open valve No. 0 and purge the pipelines 6″-PA-A1B-68001 and 4″-PA-A1B-68004. The purge pressure is 0.50–0.65 Mpa (when the pressure at D7002 is below 0.50 Mpa, close the outlet valve of D7002; once the pressure rises to 0.65 Mpa, open the outlet valve of D7002 again). Testing is conducted from outlet No. 2; it is considered successful if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes. Otherwise, purging continues until the standard is met. 7.6 After the 2# discharge outlet passes the target testing, close valve 0#, and restore the 2# discharge outlet. Once the discharge outlet is back in its normal position, sequentially disconnect flanges 208 and 191 located in front of the main factory air valves for the respective workstations. Open valve 0#. The purging pressure should be 0.50–0.65 Mpa. Perform a test by directing the purge gas at a target; it is considered successful if no rust, dust, moisture, or other contaminants are present on the target within 5 minutes. If not, continue with the purging process until the requirements are met, after which reset the system. 7.7 After the testing of the work number associated with pipeline No. 2 is successful, close valve No. 0. Reset the discharge outlet corresponding to the work number of pipeline No. 2, then remove the blind flange cover at the end of pipeline 2″-PA-A1B-68007 to use it as discharge outlet No. 3. Open valve No. 0 and purge the pipeline 3″-PA-A1B-68007. The purge pressure is 0.50–0.65 Mpa; (when the pressure at D7002 is below 0.50 Mpa, close the outlet valve of D7002, and once the pressure rises to 0.65 Mpa, open the outlet valve of D7002 again). Testing is conducted from outlet No. 3; it is considered successful if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes. Otherwise, the cleaning process continues until the standard is met. 7.8 After the testing of the work number associated with pipeline No. 3 is successful, close valve No. 0; reset the discharge outlet corresponding to the work number of pipeline No. 3, then remove the front flange of pipeline 5″-PA-A1B-9308 at V9307, using it as discharge outlet No. 4. Open valve No. 0 and purge pipeline 5″-PA-A1B-93008. The purge pressure is 0.50–0.65 Mpa; (when the pressure at D7002 is below 0.50 Mpa, close the outlet valve of D7002, and once the pressure rises to 0.65 Mpa, open the outlet valve of D7002 again). Testing is conducted from outlet No. 4; it is considered successful if there is no rust, dust, moisture, or other debris on the target plate within 5 minutes. Otherwise, purging continues until the requirement is met. 8 Precautions 8.1 Cover the removed short pipes and the flange connections of the equipment with baffles or blind plates to prevent foreign objects from entering. 8.2 Manually clean the inside of the removed short tube using steel wire. Manually pull and scrub both ends of the short pipe repeatedly, and clean the elbow of its pressure gauge; no dead corners are allowed. It is considered qualified only when there is no welding slag or dirt inside. 8.3 After the short tube has been cleaned and found to be satisfactory, it is reset. 9 Pipeline Purging Record Confirmation Form (attached later) 10. System Purging Diagram (attached later) 9.1 Air Compressor Station System Purging Record Form Pipeline No. Purging Remarks Pressure (Mpa) Medium Inspection 4″- PA -A1B-70001 6″- PA -A1B-70002 4″-A -A1B-70002 4″-A -A1B-70004 4″-A -A1B-70006 4″- A -A1B-70005 4″- A -A1B-70007 4″- A –A3B-70001 6″- A –A3B-70002 Contractor: Inspector: Date Construction Unit: Inspector: Date Supervision Company: Inspector: Date 9.2 Instrument Air Pipeline Purging Record Form Pipeline No. Purging Remarks Pressure (Mpa) Medium Inspection 6″-IA-A3B-68001 2″-IA-A3B-68013 4″-IA-A3B-68006 3″-IA-A3B-68004 2″-IA-A3B-68005 4″-IA-A3B-68006 5″-IA-A3B-93007 3″-IA-A3B-99001 Contractor: Inspector: Date Construction Unit: Inspector: Date Supervision Company: Inspector: Date 9.3 Plant Air Pipeline Purging Record Form Pipeline No. Purging Remarks Pressure (Mpa) Medium Inspection 6″-PA-A1B-68001 5″-PA-A1B-68003 6″-PA-A1B-68004 4″-PA-A1B-68004 2″-PA-A1B-68007 5″-PA-A1B-93008 2″-PA-A1B-10001 2″-PA-A1B-68006 4″-PA-A32-1A-2902 4″-PA-A1B-22201 4″-PA-A1B-20801 3″-PA-A1B-50000 Contractor: Inspector: Date Construction Unit: Inspector: Date Supervision Company: Inspector: Date