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Chemical Cleaning Requirements for DWV


Chemical cleaning requirements for DWV

The chemical cleaning solution is regularly provided by the supplier with a warranty certificate to ensure that the cleaning agent is effective and environmentally friendly. The rinsing tank used for clean water flushing adopts a flat overflow method, which requires sufficient water flow to facilitate the drainage of surface grease. Each cleaning step uses a process independent water tank. Chemical cleaning waste liquid treatment must comply with environmental protection regulations,

Process: preparation, chemical degreasing, hot water rinsing, pickling bright, clean water rinsing, spin-drying, passivation, hot-water rinse, spin-drying, and drying.Chemical degreasing: heat the ultrasonic tank to boiling, add the degreasing spirit, and boil for more than 2 minutes; the pipe fittings must be completely immersed under the liquid surface in the tank to avoid air trapping in the pipe; during the dipping process, rotate the basket at least twice. Keep the solution in the pipe fitting cavity replaced; chemically degreasing until the surface of the pipe fitting is completely wetted by someone; remove the floating oil on the liquid surface in the tank at any time.

Hot water rinsing: soak the pipe fittings in a clean water tank with a water temperature of 80°C for 1-2 minutes, rotate and lift the basket several times to remove the oily residue. The water should flow and renew.

Pickling bright: pickling bright adopts professional vibration cleaning equipment; cleaning abrasive grains are stainless steel disc-shaped particles; cleaning volume is determined according to different specifications and product sizes, one basket to two baskets; cleaning fluid is based on formula requirements, cleaning agent, brightener 1:1 ratio; 0.5L of cleaning solution with a good ratio is added each time; cleaning time is determined by the cleaning worker according to the color of the product, and the product is preferably copper or white.Rinse with clean water: Rotate and lift the basket no less than three times to ensure that the residual liquid of the cleaning agent on the surface of the pipe fittings is rinsed clean, and then the dryer is dried after draining.Passivation: The ratio of passivation agent and water is 1:15, the water temperature is 60℃, and the pipe fittings are completely immersed during soaking. The soaking time is not less than three minutes, and the basket is rotated and gently lifted every half a minute, and each basket is not less than three times to ensure a sufficient reaction.

Hot water soaking: After passivation, the basket is drained; soak it in hot water at a temperature of about 80℃ to wash away the remaining liquid after passivation; after the passivation of the pipe, if it does not affect the subsequent process or the use of the pipe, the hot water can be omitted rinse.

Drying: Pour the pipes into the tray and dry in an oven at a temperature of 100-120°C for 5-8 minutes.Maintenance: After the chemically cleaned pipe fittings pass the inspection, place them in a clean and dry area, and take dust-proof measures. The pipe fittings should be protected during transportation and should not be contaminated. The packaging of the pipe fittings should not be directly touched by hand, and clean gloves should be worn.Acceptance requirements: After the pipe fittings are chemically cleaned, they should show the true color of red copper or white and bright color. The surface should be bright and there should be no oxide scale inside or outside. Check the appearance before packaging. Serious damage, deformation, and cracks should be eliminated; after chemical cleaning, the pH of the surface of the pipe fittings can be checked with a wide range of pH test paper, and the DWV should be neutral. The unqualified pipe fittings are placed separately and will be processed after judgment.