【Haichuan Chemical Valve Knowledge】Oxygen valve degreasing methods

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I. Instructions for degreasing oxygen valves: The impurities that form on oxygen valves during manufacturing and installation include welding slag, rust, grease, dirt, etc. The presence of these impurities poses safety risks in production and causes various problems, such as the possibility of sparks leading to explosions, as well as damage to precision instruments and equipment attached to the pipelines； Blockage process flow ； It affects the quality and output of the products, among other things. Therefore, after the piping is installed or before it is put into use, it is necessary to carry out proper degreasing cleaning of the oxygen valves and oxygen pipelines, in order to remove the oil, welding slag, and other mechanical impurities that have accumulated during the valves’ manufacturing, transportation, storage, and installation processes. This ensures that the cleaned surfaces achieve the required level of cleanliness, thereby creating favorable conditions for the safe and efficient operation of the system. II. Standards for degreasing oxygen valves: Acceptance specifications for degreasing oxygen valves – HG20202; Quality standards for chemical cleaning of industrial equipment – HG/T2387; Construction and acceptance specifications for industrial metal piping projects – GB 50235. III. Methods for degreasing oxygen valves: 1. Materials used for degreasing oxygen valves: Organic solvents such as dichloroethane, trichloroethylene, and carbon tetrachloride; however, these are rarely used due to their adverse effects on the environment and human health. But it is still used when cleaning parts such as valves. Industrial alcohol is used only for rough degreasing. Compounds such as acetone 3-ketone are used only when cleaning parts like valves, as the volatile gases they produce are explosive, and they also fall under the category of controlled chemical materials. 2. Water-based degreasers: Acidic or alkaline water-based degreasers are widely used today as degreasers; since they are non-volatile, the wastewater generated can be easily treated and reused in cleaning processes. 3. Other degreasing agents: steam, used only where steam is readily available. Oil-free quartz sand or steel wool, used only for rust removal and rough degreasing, requiring oil-free compressed air as well. 2. How to degrease oxygen valves 1. Degrease by wiping, for parts such as valves. 2. Soaking degreasing: A method used when it is not feasible to employ cyclic degreasing for parts or equipment, or as a preliminary degreasing step before installation. 3. Circulative degreasing provides the best degreasing results; it also allows for processes such as pickling and passivation to be carried out. Using organic solvent-based or water-based degreasing agents for cleaning can yield excellent results. 3. Other requirements: In addition to having an oil content that meets the specifications, oxygen pipelines must also be free of rust and particles, and dry rather than humid (if a specific dew point is required, they must be dried to that desired dew point). If the client requires the pipes to be passivated, then both carbon steel and stainless steel pipes should be passivated. IV. Degreasing inspection method for oxygen valves: a. Inspect using ultraviolet light; no purple-blue fluorescence should be present ； b. Wipe with clean, dry white filter paper; there should be no oil stains on the paper (except for discoloration caused by metal oxidation). c. Blow with oil-free steam, collect the condensate, and place a single crystal of pure camphor there – the camphor will rotate continuously. d. Quantitative analysis of oil content: the oil content per square meter meets the requirements. e. If a dew point requirement is present, use a dew point meter to determine the dew point