Copper Pipe Corrosion

[ALAN LITTLE]

I am the Maint. Supervisor in a 712 bed correctional facility in Eastern North Carolina. We are experiencing pin holing in our type L copper pipe. Most of the problems are on the hot water water re-circualting lines, 140 degree hot water. The pH is about 7 and there are some minerals, mostly lime and calcuim. What can the cause(s) be and what are some courses of action to remedy the problem.

Rick Lail
Craven Correctional Inst.
Vanceboro, NC

[SylvanLMPParticipant]

quote:

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Originally posted by Rick Lail:
I am the Maint. Supervisor in a 712 bed correctional facility in Eastern North Carolina. We are experiencing pin holing in our type L copper pipe. Most of the problems are on the hot water water re-circualting lines, 140 degree hot water. The pH is about 7 and there are some minerals, mostly lime and calcuim. What can the cause(s) be and what are some courses of action to remedy the problem.

Rick Lail
Craven Correctional Inst.
Vanceboro, NC

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Hi Rick your pH of 7 is not bad at al as it is the exact same as NYC.

The problem is most lightly is your velocity on the hot water piping is exceeding the copper development recommendations of NO MORE THEN 5 FPS on water of 140 degrees and LESS then 2-3 FPS if the temperature is above 180 degrees.

Check your flow pressure and then you can calculate you velocity Or send me a private E mail and we can go through it mathematically.

Now let me tell you something funny this fraud calling himself a heating guy and plumber was having this kind of problem with M tubing so this moron installed “L” tubing thinking it would solve the problem

. What he did was actually make conditions worse by increasing friction due to a smaller inside diameter in this tubing.

If you have to replace any tubing make sure the installer reams the ends or your
setting yourself up for more failures do to turbulence by these restrictions.

Copper is great but the installation makes or breaks the job a lot of folks also use self cleaning fluxes that contain acid that also causes pitting to occur

PLEASE feel free to E mail if you have any questions GOOD LUCK

[GuestParticipant]

Rick, you might also want to check seals and flange gaskets on your circ pumps. Simply shut your pump down for a few minutes and see if any leaks develop after the system pressure normalizes. If there is more than one pump shut them all down at the same time.
I’ve seen situations where circulators will actually draw air into the system through a faulty shaft seal or inlet side flange which can cause oxygen pitting inside the pipes.

[GuestParticipant]

Rick, there are many theories regarding what causes internal corrosion in copper piping. You may re pipe with copper and have the same problems all over again. You treat your boiler and cooling tower water to prevent scale and corrosion, why not treat your potable water with a phosphate feeder. Check out http://www.aquasmartinc.com they sell these types of products. You also might want to talk to Bud at Suncoast plumbing, http://www.copperknight.com he sells a cathodic protection device.

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