the sprinkler frame should be immersed in a pickle bath at 15-20℃ for 2 hours.
the pickle bath should contain
5-10%flux a cid
15-20% nitric a cid
1-3% surface oper a tive substances
there must not be any chlorides present
the sprinkler should then be rinsed with normal water and then high pressure flushed at 230 bar so that the film/membrane is removed.visual check