Process for pickling and passivation of stainless steel pipe fittings

Stainless steel pipe fittings for pickling passivation operation steps:
1. The preparation work
2. Chemical degreasing
1) chemical degreasing adopts groove soaking method, in addition to tank made of steel plate, the lining of PVC or PE.
2) use 12 ~ 15% (by volume) of nitric acid chemical degreasing treatment, temperature of 40 ℃ ~ 60 ℃, time is 2 ~ 4 hours.
3) stainless steel pipe fittings soak in the tank, should pay attention to the location of the place, avoid tube saved the air.
4) in the process of soaking should move up and down or the turning of stainless steel pipe fittings, the lumen solution change constantly, in order to improve the effect. When it is necessary to take out the stainless steel pipe fittings, soaked in water flushing after.
5) chemical degreasing and stainless steel pipe surface wetting by water completely.
3. Hot water rinse
1) after oil removal of stainless steel pipe fittings are taken from the in addition to the oil tank, soaked in 40 ℃ ~ 60 ℃ hot water tank inside the rinse, 5 ~ 20 minutes.
2) hot water tank made of steel plate, the lining of PVC or PE.
3) the content of chloride ion in water is less than 25 PPM.
4. Rinse with water
1) water rinse the stainless steel pipe fittings (0.1 Mpa pressure P P) with pressure water to wash.
2) the content of chloride ion in water is less than 25 PPM.
5. Passivation
1) passivation using slot in the pool.
2) passivation channel steel plate production, spread acid plastic lining.
3) soaking groove, attention should be paid to the location of the placement, avoid tube saved the air.
4) in the process of soaking should move up and down or the turning of stainless steel pipe fittings, the lumen solution change constantly, in order to improve the effect. When it is necessary to take out the stainless steel pipe fittings, soaked in water flushing after.
6. Dry
After passivation of stainless steel pipe fittings, to grasp with clean compressed air or nitrogen blow dry, and must have enough time (at least 2 hours) in natural passivation in the air.
7. Inspection
Should be done after passivation of stainless steel pipe fittings, self-inspection, mutual inspection, acceptance and then submit qc inspectors as required.
8. To protect
1) outside need to paint the surface of the pipe fittings, such as is carried out in accordance with the coating requirements.
2) after the inspection of stainless steel pipe with plastic plug seal, in three fabric bandage to protect, and identified.
Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

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