Why flushing with steam or condensate is NOT a good practice ?
To check if a leak detection system is not facing any clogging or to unclog a leak detection system, some plants practice a flushing procedure with steam or water.
This is not recommended and even dangerous! Introducing water can lead to corrosion. Corrosion, as known, is an electrochemical reaction so corrosion can only take place when water is present.
Without water no corrosion.
The corrosion product will block the passage ways and can also block the leak detection holes.
A more threatening form of corrosion that can occur is stress corrosion cracking of the carbon steel pressure vessel wall.