Degreasing of oxygen pipelines, acid cleaning of oxygen pipelines, degreasing of oxygen pipelines in the air separation area

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This post was last edited by Industrial Cleaning 123 on 2016-4-18 at 11:44. Basis for formulating the plan: This plan was developed based on the equipment drawings provided by the client and **industry standards, taking into account the chemical cleaning plans for oxygen pipelines that our company has implemented over the years, as well as insights gained from on-site inspections. Ø HG/T2387-2007 of the People’s Republic of China, \"Quality Standards for Chemical Cleaning of Industrial Equipment\"; Ø HGJ 2020-2000, an industry standard issued by the former Ministry of Chemical Industry of the People’s Republic of China, \"Specifications for the Construction and Acceptance of Degreasing Projects\". l Necessity of cleaning: In accordance with Article 9.0.16 of the design specifications for oxygen stations, GB 50030--91, regarding the requirements for the construction and acceptance of oxygen pipelines, the following provisions must be met: Ø Oxygen pipelines, valves, and fittings should be free from cracks, scale, inclusions, etc. Surfaces in contact with oxygen must have all burrs, weld beads, slag, sand adhesion, rust, and other combustible materials thoroughly removed, to ensure that the inner surfaces remain smooth and clean. The rust removal on pipes should be carried out until their natural color is revealed ； Ø Pipes, valves, fittings, instruments, gaskets, and other accessories must all be degreased. Valves and instruments that have already been degreased at the manufacturer’s facility, and come with reliable sealed packaging along with relevant certification, do not need to be degreased again. For degreased parts made of black and non-ferrous metals, trichloroethylene or other inorganic solvents are suitable for degreasing ； For non-metallic parts that require degreasing, such as asbestos gaskets, trichloroethylene should be used for degreasing. After degreasing, it is appropriate to use ultraviolet inspection or solvent analysis methods for testing until reasonable standards are met. For pipes that have passed the degreasing process, their openings should be sealed promptly, and it is advisable to fill them with dry nitrogen. l Pre-construction preparation work Ø Party A’s responsibilities: Review the ‘Construction Plan’ submitted by Party B, submit it to the supervisor and the owner for approval, and have it issued for implementation by the owner. Ø Confirm that the construction site and the equipment to be cleaned permit cleaning operations. Confirm with Party B the location of the reserved openings for cleaning pipelines. Ø On-site utility conditions: Water source: Desalinated water, flow rate >100 m3/hr, concentration <25 ppm. Power supply: Three-phase five-wire system, 380V; one unit with 132KW capacity and another with 45KW capacity; 220V. Several lighting power supplies are required (the power supply must be provided within 50 meters of the cleaning pump station area). Ø Steam: 8-10 kg/cm2, 7-8 T/hr; the diameter of the connection pipe is DN80. Nitrogen or compressed air: clean, dry, oil-free, 0.6–0.8 MPa, 6.1.5 Ø Waste liquid treatment: Party A is responsible for coordinating with the owner, who will designate the location for waste liquid disposal; Party B is responsible for neutralizing the waste liquids from each processing step to a pH level of 6-9 before discharging them at the location specified by the owner. Ø Identify the components that are not allowed to undergo chemical cleaning; Party A shall remove them before cleaning, implement appropriate temporary connections or isolations, and restore them to their original state after the cleaning is complete. Party A is responsible for the removal and reinstallation of the components, as well as the installation and removal of temporary blind plates. l Temporary piping. Requirements for temporary piping: Ø Before installation, the interior of the temporary pipes must be free from oil, severe rust, and other impurities; a small amount of surface rust is allowed, provided that the cleanliness of the temporary pipes is maintained. The pipeline should also undergo a pressure test. Ø Before connecting to the main equipment, temporary pipelines can be washed with water first; once they are thoroughly cleaned, they can then be connected to the main equipment. The cleanliness of the pipelines shall be confirmed jointly by the owner, Party A, and Party B. Verification of equipment condition prior to cleaning: Ø Before cleaning the oxygen pipeline, a hydrostatic test and purging must be carried out; only after these steps are successful can degreasing be performed. Ø The utility conditions of water, electricity, steam, nitrogen, and compressed air meet the construction requirements. Ø The waste discharge system is unobstructed. Ø The floor at the cleaning site should be level and equipped with sufficient lighting. l Party B’s tasks: Ø Submission of plans: Provide a detailed construction plan, a waste liquid treatment plan, and any other documents required by Party A. Ø Internal staff training Ø On-site construction workers must arrive at the site on time, and the equipment and raw materials must be in place. Ø All personnel entering the site for construction must be certified and trained in accordance with the owner’s HSE requirements. Ø Provide technical training for operators. l Other tasks Ø Provide temporary piping diagrams for cleaning tasks, with dedicated personnel guiding the piping installation. Ø Confirm the location of the cleaning access port together with Party A, which can be determined based on the actual conditions of pipeline pressure testing. Ø Corrosion test pieces are suspended in the circulation tank to measure the corrosion rate. Ø Valve valves that are not related to the cleaning system (with the exception of those in the cleaning loop) are closed. To ensure cleaning quality and remove deposits from the system, the drain valves and bleed valves within the system are emptied at regular intervals. Establish a temporary cleaning system. Ø Layout of the cleaning site: The placement of cleaning pump stations, cleaning chemicals, and other construction materials must comply with the relevant requirements specified in the owner’s HSE guidelines. . The cleaning area and the raw material storage area should be clearly marked, and warning signs should be placed during operations to remind non-operators to stay away. For temporary pipeline configuration, set up the temporary pipelines in accordance with the cleaning process flow diagram. The components that have been removed and manually processed should be stored properly to facilitate their reinstallation after cleaning.