Installation of 304L stainless steel pipe
Installation of 304L stainless steel pipe
(OP)
We have 1000's of stainless steel pipework to be installed some of which will be lagged. Nearly all of it will be welded apart from connections to the equiptment. What flushing will be required? Will we need to use chemicals at all at any stage. After installation is there any kind of passivation or anything like that or is it simply flushing with water and that is it? Any advice would be appreciated as I am not a pipeing guy you see.
We also have quite a bit of carbon steel too some of which will be gunited with cement as will be under ground.
We also have quite a bit of carbon steel too some of which will be gunited with cement as will be under ground.





RE: Installation of 304L stainless steel pipe
For now, do not let the initial fill water to stay stagnant in the pipe w/o lots of high-flowrate flushing.
"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein
RE: Installation of 304L stainless steel pipe
RE: Installation of 304L stainless steel pipe
Wet lagging with a lot of cl- will probably ruin that pipe at that temp. Hopefully whoever designed it knew what they were doing.
"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein
RE: Installation of 304L stainless steel pipe
If the lagging contains Cl-, or could allow the absorption/penetration/trapping of salts then you are at high risk for external corrosion. Perhaps even stress corrosion cracking. In many applications it is common to coat the outside of stainless pipe in order to protect it from environmental chlorides.
On the inside the biggest risk is from stagnant water. Stainless likes to be kept full and flowing, otherwise impurities concentrate and you may get severe localized corrosion. The safest thing to do is to flush the system right before it is put into service. Never let water stand partially full in the pipes.
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Plymouth Tube
RE: Installation of 304L stainless steel pipe
I was hoping to get some input from a construction point of view. ie after installation do you have to use chemicals for passivation etc? Or just use water for flushing?
RE: Installation of 304L stainless steel pipe
RE: Installation of 304L stainless steel pipe
There shouldn't be a big need to passivate such a system. Conventional cleaning should be fine. You had better not be putting anything into these lines during construction other than a bit of dust.
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Plymouth Tube
RE: Installation of 304L stainless steel pipe
rmw
RE: Installation of 304L stainless steel pipe
So basically a good flush out with water will suffice then?