Pier process pipeline purging plan

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This post was last edited by Qi Mei Wang Liang_FGSY on 2020-3-3 at 10:32. 1 Project Overview: This solution is applicable to the purging and cleaning of the process pipelines related to the newly constructed second and third quay structures in the \"Project for Meeting Emission Standards for Oil and Gas in Finished Oil Loading Systems\". This project commenced in October 2017. The main tasks included: demolishing the second and third line piers and related facilities, constructing a new loading pier equipped with small flexible hoses and an awning, adding 22 sets of sealed small flexible hoses for railway loading – 10 for jet fuel, 8 for naphtha, and 4 for benzene. The loading systems were designed separately for each type of oil. A booster pump room was installed with 3 pumps, and a new oil and gas recovery system was built to ensure quantitative and sealed loading. The project has now been completed. A total of 6 new process pipelines were installed in the second and third tiers, including pipelines for jet fuel discharge, naphtha discharge, benzene discharge, methanol unloading, oil and gas recovery, and benzene oil and gas recovery. All pipelines were purged using air blasting and then replaced with qualified oil products. The detailed specifications for the pipeline are shown in the table below. Sequence Number, Pipeline Name, Starting Point, Ending Point, Pressure in Mpa, Nominal Diameter in mm, Wall Thickness in mm, Length in m, Remarks. Operational Design: 1. Jet A fuel delivery pipeline – Booster pump room, jetty: 0.51200, 6.5170; Auxiliary line: 200. 2. Naphtha delivery pipeline – Naphtha loading pump, jetty: 0.51200, 6.5170; Auxiliary line: 200. 3. Oil and gas recovery pipeline – Jetty, oil and gas recovery unit: 0.51200, 6.5170. 4. Benzene delivery pipeline – Booster pump room, jetty: 0.51100, 5170; Auxiliary line: 100. 5. Benzene oil and gas recovery pipeline – Jetty, benzene tank: 0.51150, 5.5550. 6. Methanol unloading pipeline – Jetty, main pipeline, methanol tank: 0.51200, 6.5200. Table 1: List of Process Pipelines to be Purged at the Jetty. Project Name:#######; Contractor: ￥####; Supervision Unit: #####; General Contractor: ####; Design Unit: #####; Construction Location: ￥#####. 2. Basis for Preparation: 2.1 Detailed design drawings for the “Project to Ensure Compliance with Emission Standards for Finished Oil Loading Systems”. 2.2 Standards and Specifications: “Code for Construction of Industrial Metal Piping” GB5.10235.1-2010; “Code for Pressure Piping – Industrial Piping” GB/T20801-2006; “Code for Acceptance of Construction Quality of Industrial Metal Piping” GB5.10184-2011; “Guidelines for Jet A Fuel Production”; “Jet Fuel No. 3” GB65.137-2006. 3. Preparation and Conditions for Purging or Cleaning: 3.1 Air purging of pipelines: 3.1.1 Before purging the pipelines, instrumentation, electro-hydraulic valves, flow meters, pressure gauges, filters, control valves, and other pipeline components must be temporarily removed and replaced with simulants or temporary short pipes. These components should be reinstated after the pipelines have been successfully purged. For the aforementioned valves and instruments connected by welding, protective measures such as using a bypass flow or removing the valve stem and seat and installing protective covers should be taken before carrying out purging and cleaning. 3.1.2 Before purging the pipeline, the pump should be removed and replaced with a temporary short pipe; once the pipeline purification is complete, the pump should be reinstalled in its original position. 3.1.3 Equipment and pipelines that are not allowed to be purged should be equipped with temporary blind flanges to isolate them from the purging system. 3.1.4 Before purging, it is necessary to check whether all pipe supports and hangers have been installed in accordance with the design drawings, and to assess the stability of these supports and hangers; reinforcement may be required if necessary. 3.1.5 Pipeline work is complete; it has been confirmed that there are no modifications to the piping. 3.1.6 Before purging, an air inlet is installed on the pipeline of the oil product at the inlet of the pump in the booster pump room, an exhaust outlet is provided at the end of the pipeline at the east end of the second and third pier bridges, and another exhaust outlet is set up on the branch pipe of the loading arm. The oil and gas pipeline is equipped with an inlet at the eastern end of the second and third lines, while an outlet is provided at the oil and gas recovery unit. 3.2 Pipeline Cleaning 3.2.1 Before cleaning the pipelines with refined oil, ensure that the provisions of 3.1.1 to 3.1.5 are followed. 3.2.2 Install a discharge outlet (DN50) at the eastern end of the secondary and tertiary pier decks, and lay auxiliary pipes to the oily water well in the southeast corner; ensure that these pipes are properly grounded against static electricity and connected with bonding wires. 3.2.3 Cleaning of the jet pipe for loading aviation fuel: Prepare a road tank truck; before starting the loading process, cover and compact the area where the tank truck passes over the rails and sleepers with sand to provide protection. 3.3 Before purging the pipeline system, the construction unit, the general contractor, the project management department, the factory’s administrative departments, and the specialized teams in the workshops shall jointly inspect and confirm the conditions prior to purging. 4 Construction Technical Measures 4.1 All pipes in this project are purged using the “intermittent air blasting” method. 4.2 For the purging and cleaning of pipelines, it is generally carried out in the order of main pipes first, followed by branch pipes. 4.3 Blowing discharge ports should be provided in front of equipment, valves, and instrument accessories; blowing discharge ports should also be installed at sections that are difficult to clean thoroughly, at sharp bends, and at drainage points ； When purging the main pipe, the branch pipe valves should be closed. 4.4 The medium used to purge the pipeline system should have sufficient flow rate and pressure; the cross-sectional areas of the inlet and outlet pipes should be roughly equal. The purging pressure must not be less than 0.5 Mpa, and the purging flow rate should be no lower than the operating flow rate. 4.5 During purging, the pipes should be tapped continuously; special attention should be paid to tapping areas such as welds, dead corners, elbows, and the bottom of the pipes, but the pipes must not be damaged. Wooden or copper hammers should be used for stainless steel pipes. 4.6 The emissions from purging must not pollute the environment; discharging them indiscriminately is strictly prohibited. 4.7 After the pipeline has been successfully purged, no other operations that could affect the cleanliness inside the pipeline shall be carried out, aside from the specified inspections. 4.8 When resetting after the pipeline purging is completed, the general contractor, construction unit, supervision unit, project management department, factory administrative departments, and workshops shall conduct a joint inspection, and at the same time fill out the “Pipeline Purging and Cleaning Inspection Record”. 5 Main construction methods
5.1 Flushing of general pipelines
The main pipelines and auxiliary pipelines for methanol, benzene, naphtha loading/unloading, vapor recovery, and benzene vapor recovery must be purged with air to ensure that no welding slag, dust, mechanical impurities, etc. remain. The loading arms require no treatment. After the delivery pipelines for methanol, benzene, and naphtha have been purged with air and found to be satisfactory, they are rinsed with suitable oil; the small transfer hoses and their associated pipelines are not treated separately. 5.1.1 Intermittent air blasting for purging 5.1.1.1 Clean air must be used for pipeline purging, air that is clean and does not conflict with the medium used in the pipeline. The purging is carried out using an air compressor in an intermittent manner. The flow velocity should be no less than 20 m/s, and the purging pressure must not exceed the design pressure of the piping system. To ensure the gas flow velocity during purging, this scheme employs intermittent blast purging. 5.1.1.2 During the air purging process, once it is visually confirmed that there is no smoke or dust present, a target plate covered with white cloth or painted white should be placed at the exhaust outlet for inspection. If the target plate is free of rust, dust, welding slag, moisture, and other debris within 5 minutes, it is considered acceptable. 5.1.1.3 When using air blasting to purge pipelines, appropriate safety measures should be taken. 5.1. 1.4 After the pipeline cleaning is completed successfully, it should be sealed. 5.1.2 Flushing pipes with qualified oil 5.1.2.1 Oil flushing must be carried out after air purging is completed successfully. 5.1.2.2 Before flushing, determine the discharge for the oil flushing. It must not be discharged indiscriminately, nor must it pollute the environment. 5.1.2.3 Qualified oil shall be used for pipeline flushing. First, flush the main pipeline, then flush the branch pipelines and flexibles. 5.1.2.4 When flushing the pipeline, first fill it with oil, and then carry out flushing through high-volume intermittent discharge. 5.1.2.5 When the oil discharged appears, visually, to be consistent with qualified oil and no impurities are observed in it, it indicates that this pipeline has been successfully flushed. Otherwise, repeat the rinsing according to 5.1.2.4 until it meets the requirements. 5.1.2.6 When the pipeline is emptied, care should be taken to open the vent valve at the higher part of the pipeline to prevent the formation of negative pressure. The tailings liquid is discharged into the underground well at the east end of the secondary and tertiary trestles. The waste liquid from methanol pipeline cleaning can be directly fed into the tank. 5.1.2.7 After the pipeline flushing is completed successfully, the pipeline components such as instruments, electro-hydraulic valves, flow meters, pressure gauges, filters, and control valves installed on the pipeline should be reinstalled. 5.2 Treatment of jet fuel pipelines: The main pipelines for delivering jet fuel, the loading arms, and their associated pipelines must be purged with air. After successful purging, the main pipelines for transporting finished jet fuel, the loading arms, and related pipeline equipment must also be treated. 5.2.1 Intermittent air blasting for purging 5.2.1.1 The purging of the kerosene main pipeline shall be carried out in strict accordance with the provisions of 5.1.1.1 to 5.1.1.4. 5.2.1.2 The kerosene transfer hoses and associated piping systems must be thoroughly purged. Before purging, the requirements specified in 3.1.1 must be followed to ensure that there are no weld slag, dust, mechanical impurities, etc., within the piping, thereby preventing damage or malfunction of instruments (flow meters, electro-hydraulic valves) when they are put into use. 5.2.2 Flushing of kerosene pipelines with qualified oil 5.2.2.1 The flushing of the main kerosene pipelines shall be carried out in strict accordance with the provisions of 5.1.2.1 to 5.1.2.4. 5.2.2.2 The loading nozzles and associated equipment for aviation fuel are cleaned by using road tankers for the loading process. Before cleaning, the rails and sleepers shall be protected in accordance with the provisions of 3.2.3. 6 Purging Organization 6.1 To ensure the successful completion of the purging process, a purging team is established. The members are mainly composed of construction units, supervision units, and workshops. 6.2 Purging gas source: This system uses an air compressor. 6.3 Source and Disposal of Cleaning Oil: This system uses the oil stored in the finished product tanks in the tank farm as the cleaning fluid, and the waste fluid is discharged into the workshop’s oily waste system. 7 Quality Assurance Measures 7.1 Technical personnel shall provide technical instructions to the construction units, so that the workers understand the key points of each stage in the entire process and carry out construction in strict accordance with the specified procedures. 7.2 During the construction process, relevant specifications must be strictly followed, and work shall be carried out in strict accordance with the design drawings to ensure construction quality and achieve thorough cleaning without any overlooked areas. 7.3 After the pipeline purging is completed, samples of the discharged residual liquid should be taken for testing and analysis. Samples from the main pipeline should undergo a full analysis. Sampling and analysis are conducted separately on the discharge effluents from the main kerosene pipeline and the loading arms; a comprehensive analysis is performed on the effluents from the main pipeline, while samples of the effluents from the loading arms are analyzed comprehensively at a rate of not less than 60%. For the remaining samples of effluents from the loading arms, the analysis focuses mainly on the solid particle content and appearance. The pipeline can only be approved upon successful testing and analysis of all samples. 8 Safety Technical Measures 8.1 Air emission outlets must be under the supervision of designated personnel; they should not face passageways, and must be located away from work areas as well as areas where other people and equipment are concentrated. Safety warning signs should be installed in appropriate locations. 8.2 The air compressor is of explosion-proof type, with a protection rating of F. 8.3 During purging, a no-entry zone should be established; dedicated personnel should be assigned to monitor both sides of the purging holes, and warning signs and barriers should be set up to prevent unauthorized persons from approaching. 8.4 When purging pipelines, a hammer made of iron shall not be used; instead, a wooden or copper hammer should be employed. 8.5 Blowing operations must be carried out under unified command; actions should not be taken blindly or without authorization. In particular, valves should be opened only after confirmation, and no operation shall be performed if the instructions are unclear. 8.6 Before pipeline purging, a pipeline pressure gauge that allows for easy observation by personnel should be installed to monitor the pressure dynamics within the pipeline at all times. 8.7 The site shall comply with relevant safety management regulations. 8.8 Construction at the site must be carried out in strict accordance with relevant requirements regarding occupational safety and environmental hygiene. 8.9 Relevant work permits must be obtained before starting construction, and appropriate safety measures must be implemented. 8.10 Safety Plan for Pipeline Purging 8.10.1 Possible Accident Scenarios 8.10.1.1 Personal injuries: injuries caused by being struck or falling, as well as by the jet of high-pressure gas or mechanical debris. 8.10.1.2 Damage to pipelines and equipment: contamination inside flow meters and electric valves, as well as damage caused by the jet of high-pressure gas or mechanical debris. 8.10.1.3 Severe fires: caused by static electricity from humans or equipment. 8.10.1.4 Leaks and environmental pollution. 8.10.2 Safety Emergency Supplies 8.10.2.1 Fire-fighting supplies: 5 shovels, 4 8kg dry powder fire extinguishers, 20 safety helmets, 10 fire buckets, and 10 fire blankets. 8.10.2.2 First-aid supplies: 1 first-aid kit. 8.10.2.3 Gas protection supplies: 5 air respirators, 4 combustible gas detectors, 1 pump-type four-in-one device, and 20 gas masks. 8.10.3 Accident Response Plan 8.10.3.1 In the event of personal injuries, it is necessary to immediately report to the factory management, the Quality, Safety, and Environmental Protection department, and other relevant departments. In the case of minor injuries to personnel, first apply bandages and other first aid measures; thereafter, depending on the severity of the injury, the emergency response team will decide whether further treatment is necessary ； In the event of severe injury to a person, call the 120 emergency service immediately, provide basic first aid to the victim, and seal off the scene right away. The safety supervision department conducts an investigation and collects evidence at the scene. 8.10.3.2 Damage to pipes and equipment: When damage occurs to pipes and equipment, the on-site supervisor shall immediately stop operations and promptly report to the plant management, the Quality, Safety, and Environmental Protection Department, as well as other relevant departments. Organize personnel to conduct inspections and carry out repairs if necessary. 8.10.3.3 In the event of a major fire, the purging team shall immediately cease operations, organize personnel to extinguish the fire, and promptly report to the plant management, the Quality, Safety, and Environmental Protection Department, as well as other relevant departments. The overall fire emergency commander assigns initial roles to the fire fighting team based on the situation on site, forming various teams such as the firefighting team, water supply team, rescue team, and logistics team, in order to carry out supplementary tasks before the arrival of the fire department ； This includes investigating fire situations, making preliminary assessments of people trapped, ensuring that various firefighting equipment is ready, and keeping rescue routes clear; meanwhile, maintaining constant contact with the fire department to report developments. When the fire department arrives, the emergency commander-in-chief and the on-site commander should immediately provide the fire department with a detailed account of the situation, assisting them in formulating a plan for extinguishing the fire. Fire assault teams should, guided by the principles that saving lives takes precedence over putting out fires and that control should be established first before extinguishing the fire, decisively assist firefighters in carrying out fire-fighting tasks. The supervisors of various departments (or workshops) provide firefighters and fire response teams with detailed information about the fire scene at all times, offer effective advice for extinguishing the fire, and are ready to follow the instructions of the emergency commander to participate in the firefighting efforts. They also cooperate actively with medical personnel to provide first aid and care, thereby minimizing casualties. 8.10.3.4 Leaks and Environmental Pollution: In the event of a leak or environmental pollution, operations must be stopped immediately, the leak site must be addressed promptly, and reports must be submitted without delay to the plant management, the Quality, Safety, and Environment Department, as well as other relevant departments. 9. When using pipelines for processing refined oil, the refined oil is discharged into oil sludge wells; therefore, drain valves and pipes must be installed at the ends of secondary and tertiary trestle pipelines. The valve is a DN25 gate valve, and the pipeline uses Φ30 rubber hoses. The specific material list is shown in the table below. Table 1: List of materials required for pipeline cleaning at secondary and tertiary pier structures. Sequence Number, Name, Specification, Quantity, Unit: 1. Seamless steel pipe Φ25×4, 100 meters; 2. Gate valve Z41H-25 DN25, 255 units; 3. Butt-welded flange DN25, 2.5 Mpa, 20#, 10 units; 4. Double-headed bolts M14×75, 35#/25#, 40 sets; 5. Spiral gaskets DN25/PN25, 10 units