Iron pipe in pool heater

DSLPelican

New member
Sep 28, 2010
4
First time poster.

I just started as a CPO on a 137,000 gallon YMCA pool less than 6 months old. We heat the pool with a shell and tube heat exchanger run off the boiler. I noticed that the heat exhanger is plumbed in using plain old black iron pipe. Is this going to last or will it be rusting out in a year or two? How long will the brass valves and copper propress last?
 

duraleigh

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Apr 1, 2007
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Sebring, Florida
Welcome to the forum :lol:

It's probably been there a very long time already. Controlling the pH is the key to success.
 

Richard320

TFP Expert
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Jan 6, 2010
20,446
San Dimas, CA (LA County)
DSLPelican said:
First time poster.

I just started as a CPO on a 137,000 gallon YMCA pool less than 6 months old. We heat the pool with a shell and tube heat exchanger run off the boiler. I noticed that the heat exhanger is plumbed in using plain old black iron pipe. Is this going to last or will it be rusting out in a year or two? How long will the brass valves and copper propress last?
I just hope the iron pipe is not on the pool side of the system!
 

DSLPelican

New member
Sep 28, 2010
4
Its water to water, no steam. Yes it is pool side with no markings. I have boiler operator's license and have installed and maintained water and steam boilers and piping so I do know the piping and boiler side of things. Of course most of the pool piping is Sch 80 pvc but for the 6 feet or so from the heat excahangers to the circ pumps, pool and spa, it is a combination of propress copper and black iron. Low ph chlorinated and oxygenated circulating hot water seems like a bad idea for iron pipe and pretty harsh for copper too. Should I raise a stink about it with the contractor now while the pool is still new or wait and see. The pump is a brass B&G, how long will the impeller last in spa water?
 

Bama Rambler

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Jun 22, 2009
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SouthWest Alabama
Since you're required to maintain such a low level of FC in that pool I don't think the chlorinated water will be any worse than just water. I'd at least find out why they used the iron pipe in the first place.

Is it at least painted?
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
Just went and checked my NG heater water outlet and it has a 12" section of black iron pipe also, guess its not a big issue because I have no iron problems. I imagine its for heat isolation from the header block, wouldn't want to thread plastic into that I guess.

Still would be cool to have a piece of stainless in there, shouldn't cost more than $50 to have made.
 

Bama Rambler

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Jun 22, 2009
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SouthWest Alabama
The problem with stainless and chlorine is chloride corrosion stress cracking. In our levels of chlorine it's not much of a problem but when you add heat it speeds up the process.
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
Bama Rambler said:
The problem with stainless and chlorine is chloride corrosion stress cracking. In our levels of chlorine it's not much of a problem but when you add heat it speeds up the process.

Like the 20 year old sparkling 304 stainless steel ladder in my pool? :p

Seriously this is not an issue with submerged SS products and certainly not an issue with non load bearing members that aren't exposed to chloramine gas accumulations.

http://www.imoa.info/_files/stainless_steel/Successful_Stainless_Swimming_Pool_Design.pdf

At any rate, type 316L is what I would spec for such a pipe...I've used it for far more aggresive solutions and higher concentrations of chlorine than a pool will ever see with zero issues.
 

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