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4
- #1
unclesyd
Materials
- Aug 21, 2002
- 9,819
There have been a couple of threads lately relating to the use of HCl as chemical cleaning agent so I thought I would post this little bit of information.
I was recently ask for assistance in determining the cause of a failures(leaks) in a 2 year old Austenitic SS piping System for a small manufacturing plant. They were tight lipped about their process other than to say it was confidential.
When I first walked into the manufacturing area it was obvious that there were major problems.
The system was both fabricated from both 304L and 316L 1" to 2" Sch 80 pipe and fittings. 95% of the fittings were Socket Welds, most were single pass and of medium quality, several repairs. Every experience I’ve had with socket welded SS has been bad form the get go.
Their first statement told the story.
The story was that after one year of operation the system was cleaned with HCl bought from a local swimming pool supply company. The product they made was green for several hours after startup.
About one month ago it was decided to clean the piping again with HCl. This time they used a proprietary product that had max use temperature of 150°F, they used it a 180°F to speed up the process. Here is the kicker they steamed (30 psig) for two (days the weekend). For some reason
they flushed it with water and found several leaks. They were unable to repair the leaks.
I took one leaking fitting and one not leaking for examination. It was obvious when I split the fittings as very few times had I seen as much SCC in one small area. The rest of the story is that the whole system is junk. It had cost around $60,000 two years ago and will cost at least twice this much to replace.
I recommended they get a design engineer that had the capability to redesign the piping with butt welds. Any future cleaning to supervised by a reputable chemical companies tech rep.
I was recently ask for assistance in determining the cause of a failures(leaks) in a 2 year old Austenitic SS piping System for a small manufacturing plant. They were tight lipped about their process other than to say it was confidential.
When I first walked into the manufacturing area it was obvious that there were major problems.
The system was both fabricated from both 304L and 316L 1" to 2" Sch 80 pipe and fittings. 95% of the fittings were Socket Welds, most were single pass and of medium quality, several repairs. Every experience I’ve had with socket welded SS has been bad form the get go.
Their first statement told the story.
The story was that after one year of operation the system was cleaned with HCl bought from a local swimming pool supply company. The product they made was green for several hours after startup.
About one month ago it was decided to clean the piping again with HCl. This time they used a proprietary product that had max use temperature of 150°F, they used it a 180°F to speed up the process. Here is the kicker they steamed (30 psig) for two (days the weekend). For some reason
they flushed it with water and found several leaks. They were unable to repair the leaks.
I took one leaking fitting and one not leaking for examination. It was obvious when I split the fittings as very few times had I seen as much SCC in one small area. The rest of the story is that the whole system is junk. It had cost around $60,000 two years ago and will cost at least twice this much to replace.
I recommended they get a design engineer that had the capability to redesign the piping with butt welds. Any future cleaning to supervised by a reputable chemical companies tech rep.
