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ChrisJ
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New to forum - Help testing boiler water
Hi all,
New to the forum and I'm hoping to get some help with a topic I've been struggling with. That is treating and testing steam boiler water.
There are many things I don't understand such as :
1: Total alkalinity and why is it important?
2: How to accurately measure PH especially when my water is purple from using water treatment
3: Why does a PH of around 11 or higher cause foaming and other problems when boiling? It seems a PH of 11+ causes violent boiling which causes water
to be pulled from the boiler rather than just steam.
4: What PH is best to minimize corrosion and rust in regards to cast iron?
My understanding right now is total alkalinity is how much the water resists change in PH. The higher the total alkalinity the less likely you are to
have a drop in PH?
I've been trying to keep my PH between 9 and 10 just based on information I have found in various places.
The water treatment I am currently using which causes the water to turn violet seems to contain the following :
1: Sodium Nitrite. % by weight 44.04
2: Sodium Triphosphate % by weight 23.52
3: Sodium Metasilicate % by weight 1.34
4: Citric Acid. % by weight 3.36
What I found interesting is this treatment starts out blue but turns violet after boiling? I'd love to know what actually causes that as they claim
you can adjust treatment levels by color.
The reason I chose this forum is I am hoping to understand why I am doing things rather than just what to do. I don't like doing things blindly
especially when they don't make sense to me such as trying to get an accurate PH reading using tape seems near impossible especially when the water is
purple.
Thank you for your time and go easy on me. I have close no knowledge when it comes to chemistry at this point and am willing to learn everything I
can.
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Amos
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I can't provide answers for everything but I can try to help with at least a couple of them.
Alkalinity is the capacity of a solution to neutralize acids, so rather than a measure of the pH of the system, it is a measure of how much base there
is. No matter how much you add of a particular basic compound you add, you won't be able to make the pH any higher than the cap for that compound, but
you can increase the solution's capacity to neutralize acid. So yes, it is in a way the resistance to negative change in pH.
It is my general observation that basic solutions tend to boil more violently and with a lot of spitting, which can be a major problem in reducing
their volume or obtaining clean steam from them. In addition, solutions of sodium metasilicate are much more viscous than ordinary water, which will
also impede smooth boiling. If you were to feel the solution between your fingers, it would probably be slippery and have a somewhat difficult time
drying. Finally, you may be experiencing bumping, which boiling in violent bursts rather than at an even rate, which could be caused by the solution
being too concentrated with dissolved solids or a lack of surface area for bubbles to form.
I hope I was able to help some.
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ChrisJ
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Thanks for responding!
It definitely helps some and you have me curious. If sodium metasilicate has such negative effects, do you have an idea of why it's used in steam
boiler water treatment?
I'm really curious why all of the things I listed are in the product.
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Amos
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Quote: Originally posted by ChrisJ  | Thanks for responding!
It definitely helps some and you have me curious. If sodium metasilicate has such negative effects, do you have an idea of why it's used in steam
boiler water treatment?
I'm really curious why all of the things I listed are in the product.
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Here's good old wikipedia to save the day again: http://en.wikipedia.org/wiki/Sodium_silicate#Water_treatment
You should use it for the other substances to see why they might be used.
I'm not entirely sure why a flocculant would be necessary in a boiler here, maybe it's a general water treatment product? But given the fact that the
proportion of sodium silicate is fairly low, I wouldn't say that this specific compound is a major source of your problems, but I could be wrong.
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ChrisJ
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| Quote: Originally posted by No Tears Only Dreams Now | | Quote: Originally posted by ChrisJ | Thanks for responding!
It definitely helps some and you have me curious. If sodium metasilicate has such negative effects, do you have an idea of why it's used in steam
boiler water treatment?
I'm really curious why all of the things I listed are in the product.
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Here's good old wikipedia to save the day again: http://en.wikipedia.org/wiki/Sodium_silicate#Water_treatment
You should use it for the other substances to see why they might be used.
I'm not entirely sure why a flocculant would be necessary in a boiler here, maybe it's a general water treatment product? But given the fact that the
proportion of sodium silicate is fairly low, I wouldn't say that this specific compound is a major source of your problems, but I could be wrong.
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Ah, interesting.
Perhaps it's there to cause impurities in the water to sink to the bottom of the boiler to later be removed during a blowdown.
The treatment in high dosages is said to work as a good cleaner to remove scale and sediment buildup. The downside is you can't really use the boiler
during this because you can't keep the water in it.
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macckone
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Sodium Nitrite is a corrosion inhibitor.
Citric acid is to remove scale.
Sodium Triphosphate is a detergent commonly used
on steel to help remove rust and is acidic.
Sodium metasilicate is used as a defloculant.
Both sodium triphosphate and sodium metasilicate
can cause foaming which is bad in a boiler system.
The blue to purple color change suggests a pH indicator.
Before boiling the calcium carbonate load of the water
will be high but it is forced out of solution by boiling.
It is one of the relatively few compounds that is
less soluble at high temperature.
Citric acid will dissolve most metal oxides and carbonates.
The sodium nitrite will also lowers oxide levels which is
important in protecting steel.
Sodium Triphosphate is an acidic form which binds with
calcium as well as iron oxide. This helps remove rust but
can cause foaming.
Sodium metasilicate is used to settle out particles in the
system which should be removed during blowout.
It can also cause foaming.
Larger systems have a treatment tank followed by
a filter before the boiler. They also have deaerators.
Things to remember in a boiler system.
Carbon Dioxide and Oxygen in the system is bad.
Too high of an alkalinity means too much dissolved
calcium carbonate.
Feed water to the boiler should be deionized or demineralized
with the later being more common.
Additionally the feedwater should be deaerated.
Most of this is difficult for a home system but normal
maintenance for a commercial system.
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ChrisJ
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| Quote: Originally posted by macckone | Sodium Nitrite is a corrosion inhibitor.
Citric acid is to remove scale.
Sodium Triphosphate is a detergent commonly used
on steel to help remove rust and is acidic.
Sodium metasilicate is used as a defloculant.
Both sodium triphosphate and sodium metasilicate
can cause foaming which is bad in a boiler system.
The blue to purple color change suggests a pH indicator.
Before boiling the calcium carbonate load of the water
will be high but it is forced out of solution by boiling.
It is one of the relatively few compounds that is
less soluble at high temperature.
Citric acid will dissolve most metal oxides and carbonates.
The sodium nitrite will also lowers oxide levels which is
important in protecting steel.
Sodium Triphosphate is an acidic form which binds with
calcium as well as iron oxide. This helps remove rust but
can cause foaming.
Sodium metasilicate is used to settle out particles in the
system which should be removed during blowout.
It can also cause foaming.
Larger systems have a treatment tank followed by
a filter before the boiler. They also have deaerators.
Things to remember in a boiler system.
Carbon Dioxide and Oxygen in the system is bad.
Too high of an alkalinity means too much dissolved
calcium carbonate.
Feed water to the boiler should be deionized or demineralized
with the later being more common.
Additionally the feedwater should be deaerated.
Most of this is difficult for a home system but normal
maintenance for a commercial system. |
Wow.
Thanks for responding! And that is an impressive response.
I have not tested total alkalinity but I have tested my TDS and it's in the low 500s.
Where does the calcium carbonate come from?
The product I am using is Steamaster tablets by Rectorseal. Am I right in assuming as long as my dose is low enough that I'm not foaming, it's safe?
Sunday I did some cleaning and ended up with a bit too much so I drained and added enough fresh water to get things back to normal.
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Bezaleel
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Calcium carbonate is almost always dissolved in tapwater. It simply comes from the source of the tap water. The higher the concentration, the 'harder'
the water is. Concentrations are strongly dependent on the region you live in.
Note that in some regions also considerable amounts of iron hydroxide/oxide are present in tap water. This will cause the chalk residues in boiling
equipment to turn brownish.
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aga
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If you imagine rain falling in the mountains, percolating through the rocks, then joining a river somewhere before hitting the reservoir, and becoming
part of your water supply piping.
The rainwater contains a tiny amount of carbon dioxide.
Carbon dioxide in water forms the weak acid Carbonic acid.
The rocks contain calcium oxide (limestone) and hydroxide due to the water.
This reacts with the carbonic acid to create calcium carbonate.
Depending on what is in the rocks that the water has passed through, you can have all sorts of stuff in your tap water - Iron, Aluminium, Crocodiles,
Uranium ...
[Edited on 7-1-2015 by aga]
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ChrisJ
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Thank you all for replying!
Besides the dosage question (is it safe as long as the boiler isn't foaming?)
I'm also wondering if Sodium Metasilicate in the treatment product helps remove oil from the water which typically floats on top?
I added some new piping in the fall and just got around to skimming the boiler last weekend and it didn't seem like any oil was in it. Would Sodium
Metasilicate have mixed with the oil and caused it to fall to the bottom where it would've been removed during a blowdown? Normally oil will float on
the water forever or until you skim from the top.
Seemed really odd to me unless there was far less oil in the new pipes and fittings than I thought.
[Edited on 1-7-2015 by ChrisJ]
[Edited on 1-7-2015 by ChrisJ]
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aga
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Fatty stuff will always float on water, if it is less dense.
Stuff that falls out of the water as a solid is called a Precipitate.
If you have a mix of stuff in water that forms a precipitate, then something(s) reacted to create new chemical structures.
Exceptions are things like very fine particles suspended in the water, which normally remain suspended in the water due to their very low weight.
A Flocculant, such as Sodium Metasilicate, basically makes those particles stick together, making the combined mass big enough to make it fall out of
the water.
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ChrisJ
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| Quote: Originally posted by aga | Fatty stuff will always float on water, if it is less dense.
Stuff that falls out of the water as a solid is called a Precipitate.
If you have a mix of stuff in water that forms a precipitate, then something(s) reacted to create new chemical structures.
Exceptions are things like very fine particles suspended in the water, which normally remain suspended in the water due to their very low weight.
A Flocculant, such as Sodium Metasilicate, basically makes those particles stick together, making the combined mass big enough to make it fall out of
the water. |
Ah ok. So oil stays on top.
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macckone
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Maybe, oil by itself will float but when combined in particles with sodium metasilicate and sodium triphosphate it could be sequestered and sink or
even be taken into solution.
Flocculants don't necessarily change things chemically to work.
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Amos
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I'd like to caution the notion that calcium carbonate is the factor causing the alkalinity; ChrisJ mentioned that the pH was 11, which is far too high
for calcium carbonate to be causing it(pH 9), especially given that it is virtually insoluble in the first place. Solutions of sodium metasilicate are
always basic unless acidified, so it could be a contributing factor.
Citric acid will not be performing as an acid in these highly basic conditions, rather it will be present as various dissolved citrate salts, which
may precipitate insoluble citrate complexes? No idea.
And aga, if limestone was composed of calcium oxide, your skin might start to bubble when you touch it. Limestone is calcium CARBONATe, generally.
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ChrisJ
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| Quote: Originally posted by No Tears Only Dreams Now | I'd like to caution the notion that calcium carbonate is the factor causing the alkalinity; ChrisJ mentioned that the pH was 11, which is far too high
for calcium carbonate to be causing it(pH 9), especially given that it is virtually insoluble in the first place. Solutions of sodium metasilicate are
always basic unless acidified, so it could be a contributing factor.
Citric acid will not be performing as an acid in these highly basic conditions, rather it will be present as various dissolved citrate salts, which
may precipitate insoluble citrate complexes? No idea.
And aga, if limestone was composed of calcium oxide, your skin might start to bubble when you touch it. Limestone is calcium CARBONATe, generally.
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I don't know what my ph was when the boiler was priming (water being pulled into mains).
I know right now it's between 9 and 10 and things are happy. But, it also sounds like the chemicals alone could cause foaming issues, ph aside.
Measuring ph is something else I think I need to improve on. I'm using these and am planning on switching to a much coarser version that does from 6
to 11.
This is what I've been using.
https://www.microessentiallab.com/ProductInfo/F03-WIDRG-0001...
This is what I ordered as it seemed to be much better for my uses
https://www.microessentiallab.com/ProductInfo/F01-WIDRG-0601...
Minor issue is I contacted their tech support and was told neither of these are intended for testing water and that I should use one of their water
testing kits. Thing is, neither water testing kit they offer does the range I want.
How could these general purpose strips that say they can be used for many things, not be for water!?
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ChrisJ
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Here are two videos showing the difference between a good amount of treatment, and when I had too much.
Surprisingly there were no other symptoms at the time so I guess I didn't go too far, but enough to raise the pressure quite a bit.
Normal conditions
http://youtu.be/ssTosd_UiWY
Too much water treatment
http://youtu.be/NAtcDLePJis
Surprising to me, even with too much treatment my water line stayed very stable. I'm guessing if I added more, this would have changed fast.
http://youtu.be/dPIx0xnEVUo
The steam was from a bucket of hot water I had drained from the boiler that was directly under the camera.
[Edited on 1-8-2015 by ChrisJ]
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macckone
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Alkalinity is not the same as pH.
Alkalinity is a measure of ions in solution that will react with acid to neutralize it.
pH is the actual amount of H+ ions in solution.
Based on the information provided the alkalinity is probably ok as is the pH.
Citrates are generally soluble salts.
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ChrisJ
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| Quote: Originally posted by macckone | Alkalinity is not the same as pH.
Alkalinity is a measure of ions in solution that will react with acid to neutralize it.
pH is the actual amount of H+ ions in solution.
Based on the information provided the alkalinity is probably ok as is the pH.
Citrates are generally soluble salts. |
Ah,
You just gave me exactly what I needed to find useful information on PH vs total alkalinity. Just searching for either usually brings up pool
websites and is useless.
I finally get it.
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feacetech
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measure P2 alaklinity by adding BaCl (in excess) and phenolphthalein and titrating (this will tell you how much caustic you have in the boiler).
Three types of alaklinity P1 P2 and total.
Not sure why the high pH is causing carry over, if fat is getting back through with the condensate this can cause foaming and carry over if not total
boiler shut down to due to high and low level alarms from soap formation. Your chemicals seem odd and I guess is they are an easy one step treament
that wont fit all applications.
How are you dosing the boiler dose pot or pumps?
Measure your condensate return if you have any (tds, turbity).
Meaure the TDS (condcutivity) of the boiler and the feed then you can estimate cycles.
Also measure phosphate levels (since you are using a phosphate treatment). Too much can be just as bad as none.
You are using a sulfite as an oxygen scavenger you can get test strips that measure sulfite levels(like pH paper (Merk make them) the pink colour of
your water might be a problem they go pink the more sulfite you add).
Are you pretreating the the feed water (softner or demin)?
Are you preheating the water before it goes into the boiler to help drive off oxygen.
Qulaity of your raw water will determine the best treatment, measure total harndess, TDS, pH, silica.
Then if you run a pretreatment measure your feed water conductivity, hardness and silica.
By the look if it you are runnign a phosphate programe so you probably have little in the way of pretreatment. You are trying to do a couple of things
in the boiler.
Remove the carbonate (to prevent scale build up on hot surfaces) as a mobile serpentine phosphate sludge and thus blow it out of the boiler via bottom
blowdown.
You are trying to remove all dissolved oxygen to prevent corrosion having a sulfite reserve in the boiler would mean that all oxygen is scavenged.
You are keeping the pH high to avoid silica scale and also encourage the formation of magnitite in the boiler to help prevent corrosion (silica scale
is by far the worse type of scale very hard to remove). If silca is very high it can carry over (bad block heat exchangers etc).
TDS and cycles is key to running a good boiler (15-20 cycles). The lower the better if you have a dirty scaly boiler.
Sodium lignosulfonate is good for dirty boilers.
Sodium erythorbate is good for metal passivation and oxygen scavenging in conjunction with a sulfite.
Are you worried about condensate corrosion and can you add a volatile/filming amine? Not if its a food application.
I could be wrong, and you are using high quality feed water and are running a chelation programe(The cirtic acid!)?
What sort of boiler is it, fire tube or water tube?
Carbonate has retrograde solubility (is less soluable in hot water) so it sticks to the hot surfaces of your boiler, plus it is a good insulator so
you loss efficency in your boiler, also it can cause under deposit corrison, worse case is your firetube may warp if its a firetube boiler (metal gets
very hot because its insulated by concrete).
To much caustic can cause caustic embrittlement of the metal over time.
I would be very carfull about using citric acid in your boiler, over use will eat your boiler up plus remove any good coatings you have formed.
If you have no pre treamnet and a typical raw water (~100 tds, some carbonate hardness, not much silica, low cholride, normal pH 6-8)
I would get a water softner and run a phosphate programe just in case you get slipage or your softner fails.
Phosphate additive, caustic and a sludge modifier. Plus a sulfite and a vitamin c analouge in the feed. (the more preheat the less sulfite you will
need). Alkaline tanins can work if its not food related in application.
run a sulfite reserve of 10-30ppm.
P2 alk of 300-600ppm.
Phosphate depends on the additive about 20-50ppm depedning on the type.
pH 10.5-12, I think 11.2 is the magic number.
20 cycles max, by the sound of it your boiler doesnt work hard and has low cycles anyway? (unless you have good feed water low tds).
[Edited on 8-1-2015 by feacetech]
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aga
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I don't know if more pH explanation will help (or if my understanding is totally correct) but here goes anyway ...
When an atom or molecule loses or gains an electron, it gains or loses a Charge of 1, and is called an Ion.
(some can lose or gain more than 1)
Hydrogen has only 1 proton and 1 electron, so if it loses it's electron, it has an overall Positive charge of +1
pH is a measure of the Concentration of those positively charged electron-deficient Hydrogen Ions (H+) in the stuff you're interested in.
Fairly recently it has been discovered that H+ doesn't really exist, it's H3O+ in reality, but the pH scale was worked out before that
discovery.
pH is defined as the Negative log of the Concentration of the H+ ions.
Concentration is a strange one : it's measured as how many molecules/atoms there are in 1 Litre, and the 'how many' is measured as how many Advogadro
Contant molecules/atoms there are in a litre, rather than a simple count (!).
So that's the actual number of molecules/atoms divided by 6.022 * 10^23 there are in a Litre, also called the Molar Concentration, normally stated as
[M].
It sounds odd, yet it makes more sense than dealing with Vast numbers of particles.
e.g. The Mass of 6.022 * 10^23 bits of an Element is what you find as it's mass on the periodic table.
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ChrisJ
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| Quote: Originally posted by feacetech | measure P2 alaklinity by adding BaCl (in excess) and phenolphthalein and titrating (this will tell you how much caustic you have in the boiler).
Three types of alaklinity P1 P2 and total.
Not sure why the high pH is causing carry over, if fat is getting back through with the condensate this can cause foaming and carry over if not total
boiler shut down to due to high and low level alarms from soap formation. Your chemicals seem odd and I guess is they are an easy one step treament
that wont fit all applications.
How are you dosing the boiler dose pot or pumps?
Measure your condensate return if you have any (tds, turbity).
Meaure the TDS (condcutivity) of the boiler and the feed then you can estimate cycles.
Also measure phosphate levels (since you are using a phosphate treatment). Too much can be just as bad as none.
You are using a sulfite as an oxygen scavenger you can get test strips that measure sulfite levels(like pH paper (Merk make them) the pink colour of
your water might be a problem they go pink the more sulfite you add).
Are you pretreating the the feed water (softner or demin)?
Are you preheating the water before it goes into the boiler to help drive off oxygen.
Qulaity of your raw water will determine the best treatment, measure total harndess, TDS, pH, silica.
Then if you run a pretreatment measure your feed water conductivity, hardness and silica.
By the look if it you are runnign a phosphate programe so you probably have little in the way of pretreatment. You are trying to do a couple of things
in the boiler.
Remove the carbonate (to prevent scale build up on hot surfaces) as a mobile serpentine phosphate sludge and thus blow it out of the boiler via bottom
blowdown.
You are trying to remove all dissolved oxygen to prevent corrosion having a sulfite reserve in the boiler would mean that all oxygen is scavenged.
You are keeping the pH high to avoid silica scale and also encourage the formation of magnitite in the boiler to help prevent corrosion (silica scale
is by far the worse type of scale very hard to remove). If silca is very high it can carry over (bad block heat exchangers etc).
TDS and cycles is key to running a good boiler (15-20 cycles). The lower the better if you have a dirty scaly boiler.
Sodium lignosulfonate is good for dirty boilers.
Sodium erythorbate is good for metal passivation and oxygen scavenging in conjunction with a sulfite.
Are you worried about condensate corrosion and can you add a volatile/filming amine? Not if its a food application.
I could be wrong, and you are using high quality feed water and are running a chelation programe(The cirtic acid!)?
What sort of boiler is it, fire tube or water tube?
Carbonate has retrograde solubility (is less soluable in hot water) so it sticks to the hot surfaces of your boiler, plus it is a good insulator so
you loss efficency in your boiler, also it can cause under deposit corrison, worse case is your firetube may warp if its a firetube boiler (metal gets
very hot because its insulated by concrete).
To much caustic can cause caustic embrittlement of the metal over time.
I would be very carfull about using citric acid in your boiler, over use will eat your boiler up plus remove any good coatings you have formed.
If you have no pre treamnet and a typical raw water (~100 tds, some carbonate hardness, not much silica, low cholride, normal pH 6-8)
I would get a water softner and run a phosphate programe just in case you get slipage or your softner fails.
Phosphate additive, caustic and a sludge modifier. Plus a sulfite and a vitamin c analouge in the feed. (the more preheat the less sulfite you will
need). Alkaline tanins can work if its not food related in application.
run a sulfite reserve of 10-30ppm.
P2 alk of 300-600ppm.
Phosphate depends on the additive about 20-50ppm depedning on the type.
pH 10.5-12, I think 11.2 is the magic number.
20 cycles max, by the sound of it your boiler doesnt work hard and has low cycles anyway? (unless you have good feed water low tds).
[Edited on 8-1-2015 by feacetech] |
Wow, feacetech you just went so far over my head I can't even see you. 
This is a home heating steam boiler. It's not a tube boiler but rather what I believe is called a pin type where it's just a cast iron block with
passages through the water lined with stubs.
I just happen to be very anal and learned very fast that raw water wasn't a good idea. I use around 1/2 gallon of water per month and do not have an
autofeeder. I manually feed while the burner is firing and when I know it will boil the fresh water for a while. The high PH causing foaming was an
assumption I had made based on what I had been told in the past but this could easily be false. That's why I'm here, to learn the right way to do
things and understand why I'm doing them. I'd like to talk more if possible? Is there another way to contact you?
I've attached two pictures of the boiler from when I was installing it back in 2011.
More pictures of the project can be found at this URL
https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sR...
 
[Edited on 1-9-2015 by ChrisJ]
[Edited on 1-9-2015 by ChrisJ]
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aga
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| Quote: | | I'd like to talk more if possible? |
Keep it Public and open : we all learn more that way !
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ChrisJ
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| Quote: Originally posted by aga | | Quote: | | I'd like to talk more if possible? |
Keep it Public and open : we all learn more that way ! |
Oh, alright.
By the way, thank you for your PH explanation. It was helpful.
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feacetech
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So you add make up water manually? If so losses must be really low?
You could fill with DI water (deionised water you can get filters that do this TDS should be close to zero), boil b4 you put it in to de-aerate it,
add some tablets at required dose and you should be all good. Check you TDS before you put it in (if you have a conductivity meter then you can
estimate cycles). the only real way to get stuff out of the system is from blow down if you have no losses. Steam losses will increase your TDS
(total dissolved solids) and therefore your treatment chemicals and unwanted dissolved ions. If its closed loop it shouldn't need
much blow down or make up.
That we tap on the side looks like a blow down or is it a sample port (or both lol)? Does it have automatic blow down, manual bottom blow down or
none apart from sample port/manual side blowdown?
I was picturing a larger fire tube boiler for a large scale home brew operation or an industrial boiler you wanted to find out more about :p.
Just to be sure is it a steam generator or a pressurised hot water boiler? this is important to determine what sort of treatment you
want.
Not sure what's on the consumer market for these sort of things, but your choice should be dependent on your feed water quality. The better the
quality the more fancy treatment you can try and succeed with and have nice efficient long lasting boiler (like your tablets).
An option if its a closed loop hot water boiler on low quality feed is to find a cheap industrial treatment with Alk and tannins and
some phosphate and you should be good. Tannin is cheap and long lasting and good for some one who doesn't want too much effort.
Phosphates/phosphonates form a sludge with the Ca and Mg hardness and higher alkalinity encourages the formation of magnetite among other things.
Tannins as a long lasting oxygen scavenger.
There's a test for tannins it involves some KMnO4 tablets and is very easy. You can get phosphate test strips and sulphite test strips as well.
Catalysed sulphite is very fast at oxygen scavenging and good.
Tannins and slower but hold a reserve for longer.
Having the system turn off and cool down is also the enemy as it can create a vacuum that sucks in unwanted atmosphere that dissolves in the water
once the system cools down and consumes oxygen scavengers. Gasses are more soluble in cold water as a rule of thumb.
What is the trade name of the tablets and what are the recommended parameters for the treatment?
Since its small and probably delicate you want to go for the highest quality feed water with the best treatment IMHO.
It should be spotless on the inside and a nice gunmetal grey if done right.
Also when I was talking cycles I meant cycles of concentration basically how much more times concentrated your bolier water is vs feed water. You can
estimate this by (TDS of system)/(TDS of Feed water). Low TDS treatment is more advanced than hard water treatment.
If it is in fact a steam boiler for best results you want to have a mildly alkaline low TDS treatment and make up with high quality
feed water (very low TDS).
Think of it like this if you have high grade feed water you just have to worry about minute impurities (Chelation) and concentrate on
corrosion (oxygen-scavenger and pre heating if you don't what to waste chemicals) and metal passivation instead.
[Edited on 9-1-2015 by feacetech]
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ChrisJ
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Registered: 7-1-2015
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| Quote: Originally posted by feacetech | So you add make up water manually? If so losses must be really low?
You could fill with DI water (deionised water you can get filters that do this TDS should be close to zero), boil b4 you put it in to de-aerate it,
add some tablets at required dose and you should be all good. Check you TDS before you put it in (if you have a conductivity meter then you can
estimate cycles). the only real way to get stuff out of the system is from blow down if you have no losses. Steam losses will increase your TDS
(total dissolved solids) and therefore your treatment chemicals and unwanted dissolved ions. If its closed loop it shouldn't need
much blow down or make up.
That we tap on the side looks like a blow down or is it a sample port (or both lol)? Does it have automatic blow down, manual bottom blow down or
none apart from sample port/manual side blowdown?
I was picturing a larger fir tube boiler for a large scale home brew:p.
Is it a steam generator or a hot water boiler? this is important to determine what sort of treatment you want.
Not sure what's on the consumer market for these sort of things, but your choice should be dependent on your feed water quality. The better the
quality the more fancy treatment you can try and succeed with and have nice efficient long lasting boiler (like your tablets).
If its a closed loop hot water boiler find a cheap industrial treatment with Alk and tannins and some phosphate and you should be good. Tannin is
cheap and long lasting and good for some one who doesn't want too much effort.
There's a test for tannins it involves some KMnO4 tablets and is very easy.
Catalysed sulphite is very fast at oxygen scavenging and good.
What are the tablets and what are the recommended parameters for the treatment?
You can get phosphate test strips and sulphite test strips as well
Since its small and probably delicate you want to go for the highest quality feed water with the best treatment IMHO.
It should be spotless on the inside and a nice gunmetal grey if done right.
Also when I was talking cycles I meant cycles of concentration basically how much more times concentrated you water is vs feed. You can estimate this
by (TDS of system)/(TDS of Feed water).
If it is in fact a steam boiler for best results you want to have a low TDS treatment and make up with high quality feed water (very low TDS).
Think of it like this if you have high grade feed water you just have to worry about minute impurities (Chelation) and concentrate on
corrosion (oxygen-scavenger and pre heating if you don't what to waste chemicals) and metal passivation instead.
[Edited on 9-1-2015 by feacetech] |
I try to keep my losses to a minimum, typically 1/2 gallon of water per month if it's fairly cold out.
This is a steam boiler and my feed water is city water with a typical PH of 7 and TDS is usually around 250 ppm if memory serves. I just checked the
boiler's TDS on the weekend and had 512.
The tap on the side is known by the manufacturer as "the boiler drain". Sadly, home heating boilers like this don't get much attention from their
owners and most don't even know what a blow down is.  They also often rely on
autofeeders which almost always add water right before the boiler shuts down and most don't even keep track of how much is added.
We bought this house in 2011 and the previous owner rotted two boilers out in 8 years due to leaks and low PH. From the short time I saw the leaking
boiler work I'd say it was taking in a gallon or more of fresh water per day and no one cared because an autofeeder was doing it.
My return water has a TDS of between 1 and 2 ppm which I understand means the steam I am producing is very dry vs the boiler's 500+ ppm.
Before I started using treatment when I measured the boiler water's PH I found it was around a low 6. I found this surprising as my tap water is
pretty much always a 7. My understanding is this takes place due to the water absorbing carbonic acid after condensing in the radiators and trickling
back through the system? Again, this is what I had heard from someone 3 years ago so I could be wrong, just like the high PH causing foaming.
Now, as far as the pills I am using they are Rectorseal Steamaster tablets. The problem is, I think their instructions assume a far larger boiler
because they want me to use 12 pills based solely on my boiler's output. The issue is, my system only holds 10 gallons of water and even 3 pills
causes foaming and carryover. I know quite a few people using these pills and not one of them can go past 2 pills in a home heating system. In fact
many can't use over 1 pill.
You're right, these boilers do seem fairly delicate. Sadly, many rott out in 5-10 years due to abuse. No water treatment, no blowdowns, access
makeup water added constantly due to leaks etc.
Almost always they rott out just above the water line.
What I can say for the Steamaster tablets is the difference between them and plain water in my system is night and day. Before them my water was
always rusty, anytime I drained water it was dark brown, nasty and rusty. I started using the tablets in 2012 and ever since I never see rust in the
gauge glass and when I do a blow down after several months there's practically no rust.
I've attached a picture from 2012 showing what my gauge glass used to look like for the first year I ran the boiler. After using treatment that glass
stays practically spotless. After an entire season it will get a slight rust cloud on it, but nothing like before. I try to keep the PH between 9
and 10 but have had a hard time reading the Phydrion tape I have because 9 10 and 11 look almost the same. The purple color isn't helping either.
I do expect some rust as the entire system is open to the atmosphere. Everytime I produce steam it pushes air out of the system and then afterwards
more air gets sucked in. That combined with steel piping, cast iron fittings and cast iron radiators means rust. I've also heard distilled water
attacks metal more than normal tap water? If that's the case it's surprising how long cast iron radiators last.
My system typically runs at around 1"WC and I try to keep the pressure as low as possible by venting fast. Most systems like this unfortunately run
as high as 2 PSI due to slow venting and grossly oversized boilers.
[Edited on 1-9-2015 by ChrisJ]
[Edited on 1-9-2015 by ChrisJ]
[Edited on 1-9-2015 by ChrisJ]
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