Encasing a flange?

[Pump2005]

I have a two sections of 10" pipe connected at flanges. The flanges look like they were made on-site when they were put in 35 years ago. One of the flanges developed a crack from one of the bolts. it's at the point where it drips to the floor and Marine-Tex didn't work as it has developed other drips when the water was turned back on and hard to tell since the pipe has been painted about 15 times. The section can't be taken out until next fall when we are doing an upgrade. Is there a sealant I can use to coat the entire flange in until a proper fix can be done. There are household applications but I need something more industrial. Anyone's suggestions would be appreciated.

Rob

 

[bimr]

No familiar with any encasing technique.

If the leak is bad enough, there are various techniques such as a hot tap that can be used to repair/replace the segment.

 

[Pump2005]

Thanks bimr. It is a vertical header inside my treatment plant going from my influential/effluent line that leads up to my backwash valve so it's not in the ground. I found one crack to a bolt but with all those years of paint before I got there it's hard to tell where the other drips are coming from as they are running under the paint. I found some sealant online that I'm going to try since the plant is off until the spring. I've found similar cracks at other bolt flanges in the plant but can't figure out the cause other than age.

 

[LittleInch]

There are many encapsulating systems. Search pipe flange repair clamp.

You find thinks like this

http://www.pipelinecoupling.com/pages2/flange-leak-repair-clamp.php

or

http://www.teamindustrialservices.nl/team_products/pipe_repair_clamps.htm

or sealant like this

http://www.furmanite.com/services/o...ndard-application/bolted-flange-gasket-leaks/

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Pump2005]

LittleInch, Thank you for the links. I don't see my town paying for anything mechanical as a fix. I'll try the sealant and then if it doesn't work it falls in their hands.

 

[racookpe1978]

What pressure?
What temperature?
What fluid?
What are the penalties if the "quick fix" fails? Any deadly or enviro penalties even remotely at rsik?
how much leakage?

 

[Pump2005]

Hi racookpe1978. It's potable water with influent system pressure coming in at 45psi but the effluent service pumps will run at 55psi but much higher when the pumps first kick on. Same pipe for effluent, backwash and plant water. Right now it's has multiple drips Which makes a mess on the floor and so many layers of paint that there might be other cracks hidden in it. The pipe with the leak is a pipe that rises up before the service pumps and feeds the filter backwash (1000gpm). I've been on vacation for almost all of December so I'll have to talk with the licensed operator this week. The plant is suppose to be rebuilt with pressure filters when we go off line in September but some piping right now is repaired with caulking such as Sikaflex but it's pretty embarrassing.

 

[StoneCold]

If your budget is really low you might want to try this product. We have had some success with it for leaks until it can be fixed. We have used it on cooling water. Never on a chemical transfer line or anything like that.

 

[saplanti]

In case the flanges are original and worked 35 years you may see the fatigue crack in the flanges due to the changing stresses (one need to check the stresses under operating loads, and count the probable cycle during the life time). It seems to me that The only solution for the problem is to replace them, rather that trying to fix with unusual methods. You need to maintain the installation forces on the bolts during the fixing the leak, however solving the leak problem does not reduce the stresses on the flange. In case the fluid running inside is caustic or acid you may have big problem sooner or later.

 

[ehbadger]

I have little experience with sealants but have successfully used clamp systems like the Team Industrial one linked above.

Also look into composite wraps, if you can get the dripping to an acceptable level (not sure what leak rate can tolerated during installation) they can be pretty quick way to buy some time. It is just some fiberglass wrap wound around the pipe with a resin that cures to seal it all up. I think Team Industrial does this as well. Furmanite can too... "composite repair". These should be cheaper than the mechanical clamp that you said wasn't likely.

http://www.furmanite.com/services/composite-repair/

 

[Pump2005]

Thanks for the responses. I have used the Stop-It wrap on straight pipe with good results but with cracks at bolts it's not applicable. I found another crack in a flange at a bolt today and these pumps and plant itself haven't been run since September and with the valve off there is no pressure on it. I'm starting to think it's a combination of things.
1. Years back with a prior licensed operator they decided to run the filters to waste during start up through the service pumps (vertical turbine) which is 12" to a discharge at a fire hydrant. Flow was not into the system. I think this created too much pressure on the piping.
2. I think the building itself has settled affecting the piping.

To actually correct the issue the piping should be replaced but I don't see that happening if they're working on a rebuild in September. I would like to find a thick sealant to coat those areas. I'm not in charge but I want to save myself the headache of a phone call about water running out the doors, which I have encountered before and it's not pleasant. It's just a case of the plant making a lot of money but none of that money goes back into the plant.