Questions about pickling and passivation
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There is a stainless steel device that, due to the nature of the medium used, requires a gas-tightness test or an ammonia leakage test. May I ask whether the acid washing and passivation process, which is necessary after the hydraulic test, should be carried out before or after the gas-tightness or ammonia leakage test? Why?
Generally, it’s before inside the device and after outside the device.
The acid washing and passivation inside the equipment should be carried out before or after the airtightness or ammonia leakage tests; if it is done first, the equipment will become contaminated again when the airtightness and ammonia leakage tests are conducted
Pickling and passivation should be done before making it airtight.
In our factory, the pickling and passivation of the stainless steel surface used to be carried out after ensuring water and air tightness
I’m not too familiar with the equipment, but the general process for pipes is as follows: outer pipe inspection ---- non-destructive testing ---- hydraulic testing ---- leak testing ---- purging and cleaning ---- degreasing ---- acid washing ---- water washing ---- passivation ---- water washing ---- drying with compressed air or nitrogen ---- nitrogen sealing.