Chlorides & Steam

Mad Doctor Q

Sharing what I've learned with commercial sized 200 and 300 HP steel steam boilers, and agreeing with Glen from Burnham, anything over 100ppm chlorides will require shutting the boiler off, letting it settle so your solids drop to the bottom and then perform bottom blowdowns to remove these solids, which are the results of your chlorides test. You mentioned make-up water was normal? If your system is tight, no steam or condensate leaks, the only make-up water needed should be to replace the water lost from blowing down things like the feedwater regulator,guage glass, low water cut-out, water column, etc. Fresh make-up water brings in minerals that will precipitate when heated and slowly bring up the chloride levels. Testing of boiler water for large steam boilers needs to become a routine to MAINTAIN chloride levels below 100ppm. Bottom blowdowns are a necessary evil where boiler water treatment is concerned. Welding is a costly alternative. You may have to some frequent bottom blowdowns and test to lower the chlorides, then start testing daily and keep a log to see how often you climb up past 100ppm. As glen stanton mentioned, if for his boilers 50ppm is the limit, then monitoring levels are a must. Also quality of supply water is important. Well or ground water as a supply has a higher level of mineral content. Oxygen content should also be considered if you start experiencing metal surface pitting and tube leaks. More make-up water leads to more excess oxygen. Hope this helps, sorry its late.

Will_5

Chlorides

I am very familiar with what chlorides do with stainless steel indirects but does anyone have any input on how they react on a steam boiler. I came across a steam boiler that had failed in less than five years, my first thought was make-up water or PH, both checked out to be well within the norm. I tested for chlorides and came up with a PPM that was off the charts, literally. Any thoughts?

Unknown

Did this job

happen to have a water softener that isn't functioning properly? Just curious.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Will_5

Softener

It didn't have a softner on the system, the water sample I took from the boiler registered over 500ppm. I haven't gone back to the job to obtain a sample from the incoming water yet.

clammy

cholorides and phopurus

Sorry about the spelling but i have always been told that phopopurs and other commonly used house hold chemicals should never be located to close to any make up air that will be used as combustion air ,i know from the past that dry cleaning agents will eat most heat exchangers and in all probalby cause damage to cast iron and steel burner tubes even carriers in shot type burners for i have seen it personally and it only took less then 2 months on one installation before the heat exchanger was leaking due to thecombustion air changing into a corrisive chemical mix .I woulds think that the cholirides are in all pronbablablity doing it as i always they give vlear and cut infromation about miminum combustion air requirment with the instruction of every piece of heating equipment manafactored today it just a shame that there rarely followed unless there is a issue then it's back pedaling time peace and good luck

Unknown

Followup for John

John,

Sorry for the delay in getting you an answer on this but I needed to get to the right person in Engineering about this. We would desire that the Chloride Level be below 50 ppm in our boilers. In Commercial Applications anything above 100 ppm MUST have water treatment to correct the problem. Anything above 100 ppm can be a killer! Hope this helps.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Will_5

Good info

to have Glen. It only made sense to me that high chlorides could not be a good thing.

Sunny from CT

Hi John, I did have a commercial job where the chlorides were tearing apart some CleaverBroks boilers, we searched high and low and finally found a leak in the tube bundle for the swimming pool heat exchanger.