What are the steps for pickling 304 stainless steel pipes?

Operation steps for pickling 304 stainless steel pipes.

1. Pipe ready

2. Chemical degreasing

(1) The chemical oil removal adopts the immersion method in the tank, and the oil removal tank is made of steel plate, with PVC or polyethylene laid on the inner wall.

(2) Chemical degreasing treatment uses 12-15% nitric acid (by volume) at a temperature of 40 ℃ to 60 ℃ for 2-4 hours.

(3) When soaking 304 stainless steel pipes in the tank, attention should be paid to their placement to avoid leaving air inside the pipes.

(4) During the soaking process, the tube should be moved up and down or flipped, and the internal solution should be constantly replaced to improve the effect. If necessary, remove the tube, rinse with water and gas, and then soak.

(5) Chemical degreasing until the surface of the pipe fittings is completely wet.

3. Hot water flushing

(1) Remove the 304 stainless steel sanitary pipe after oil removal from the oil removal tank and soak it in a hot water tank at around 40 ℃~60 ℃ for rinsing for 5-20 minutes.

(2) The hot water tank is made of steel plate, en die binnemuur is bedek met polivinielchloried of poliëtileen.

(3) Die chloried-ioon-inhoud in water is minder as 25 dpm.

4. Spoel met water.

(1) Gebruik drukwater (druk P ≥ 0, 1Mpa) om die pype wat gewas is met water uit te spoel.

(2) Die chloried-ioon-inhoud in water is minder as 25 dpm.

5. Passivasie

(1) Kies die passiveringsoplossingformule en weektyd volgens Tabelle 2 en 3.

(2) Produseer passiveringsgroefstaalplate met suurbestande plastiek op die binnemure.

(3) Wanneer week in die tenk, let op die plasing om lug binne die buis te vermy.

(4) During the soaking process, die pyptoebehore moet op en af ​​geskuif of gedraai word, and the internal solution should be constantly replaced to improve the effect. If necessary, die pype moet verwyder word, met water en gas gewas, en toe geweek.

6. Droog

Na passivering van die 304 vlekvrye staal sanitêre pyp, droog dit met skoon saamgeperste lug of stikstof, en daar moet genoeg tyd wees (ten minste 2 hours) vir natuurlike passivering in die lug.

7. Inspeksie

Na passivering van 304 vlekvrye staal sanitêre pype, selfinspeksie en wedersydse inspeksie moet uitgevoer word, en dan aan kwaliteit-inspeksiepersoneel voorgelê vir aanvaarding soos vereis.

8. Beskerming

(1) Pipe fittings that require painting on the outer surface shall be painted according to the painting requirements.

(2) The pipes that pass the inspection shall be sealed with plastic plugs, wrapped with three proof cloth for protection, and marked.