thanks again (shokran) Ahmed. the coupons were installed upon the advise of
the corrosion engneer. sea water is treated. we've got a hyphochlorite
treatemtn unit. there are some signs of microbes previous to the treatment.
it sneither at the top or bottom. its happening at between 3 and 5 oclcok
position. velocity is under 5 fps. color is much like that of a finish
cement. but once you'vegot corrosion between the lining and the pipe id - it
can not be arrested. we can only expect that will it get worse.
-----Original Message-----
From: Ahmed Vawda [mailto:avawda@aksugar.co.ae]
Sent: 29 May, 2001 4:15 PM
To: 'PipingDesign@yahoogroups.com'
Subject: RE: [PipingDesign] Cement Lined Piping
Ralph
Unless the corrosion coupon is of the same cement material its of no use.
Cement is made out of an alkaline material. If the water is anaerobic,
chances are you have anaerobic bugs, which produce acids, that corrode
cement.
Are there sea macro-organisms, mussels etc, lining the inside of these
pipes?
What is the water velocity in the pipe? Are there suspended solids in the
water, i.e. sand, shells etc.
Any evidence of the microbes previously mentioned?
Describe the leaks, i.e. holes, softening of the concrete, cracks, whatever
etc.
Are the leaks at the bottom or top of the pipe?
Colour and texture of the concrete at the leak area.
Regards
Ahmed Vawda
Process Engineer
Al Khaleej Sugar
Dubai
-----Original Message-----
From: SARE, RALPH H. [mailto:SARERH@YANPET.SABIC.com]
Sent: Tuesday, May 29, 2001 2:17 PM
To: <a href="/group/PipingDesign/post?postID=qzojYSBtY2DCYXD6mspMfjZ12kc7AoYYRoPn-4_Vie152WXLWieYnvMpLsmdor2iTKjuDKnrxliLuFq5FKZiPgx57w">PipingDesign@yahoogroups.com</a>
Subject: [PipingDesign] Cement Lined Piping
We have experienced a lot of leaks on our sea water cooling system. The 56" CS pipe is cement lined and was commisisioned way back in 1985 (FBE was not yet popular at that time). Its about a few kilometer long and has a coouple of inspection port, bends and branches. Anyone has a suggestion on how to rehabilitate the pipe short of replacing it. Ive got only a 5 days window. Damn corrosion coupon is of little use. We're surviving using the Belzona product (more expensive that gold on a per pound basis) to currently fix the leaks.
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Your use of Yahoo! Groups is subject to <a href="http://docs.yahoo.com/info/terms/">http://docs.yahoo.com/info/terms/</a> Received on Wed May 30 01:10:00 2001
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