Concrete Encasing A Pipe 1

[AAEC]

Present Situation:
12" DIA. carbon steel externally painted pipe use to bypass cooling water is partially corroded at the bottom area. The bottom area is resting (maybe partially buried) on top of a concrete slab which is the reason why it got corroded due to moisture. The pipe has a pressure of about 4psig from a water basin about 9ft deep.

Constraint: Cannot isolate the pipe since we cannot afford to shutdown the whole refinery operation. Cannot place the plug at the end since the water is very murky and lots of variables to deal with. Cannot utilized pipe wrap since we need to clean out the area first which will disturb the corroded area and create an uncontrolled leak.

Goal: To prevent the pipe from having an uncontrolled leak due to corrosion.

Solution: We are planning to concrete encase the pipe to prevent uncontrolled leak. Basically to use the concrete (when it is hardened) as a containment pipe when all the steel is gone. (See my attached drawing). This solution is a 3 year solution. We will eventually replace the pipe with a new one.

Question: I could not find any standard or similar design so I created one base on inputs from our operation personnel. Do you think my design is okay to prevent an uncontrolled leak? Any recommendation will be appreciated.

Thanks!

 

[bimr]

Seems like you are going to a lot of trouble for a 12" pipe. You can get a 12" stainless steel pipe clamp:

http://www.uspvh.com/catalog.asp?prodid=70

Steel components tend to corrode slowly rather than in a catastrophic or uncontrolled mannner. So a simple clamp may suffice.

However, should you use your repair method, it should work because of the low water pressure.

 

[cvg]

unreinforced concrete is not watertight and cannot contain much pressure. Corrosion will continue and will eventually extend beyond the limits of the encasement. The encasement may work for a while, the clamp will work just as well. This is just a short term bandaid. Eventually you will need to deal with this and replace the pipe.