Rust in Sight Glass Only

SusanC

I didn't realize I was responding to a 2006 question when I wrote the following so am putting it in the current steam section of The Wall also - sorry about duplication:rusty water in sight glass also

I'm wondering if something in the Weil-McLain set-up attracts rust to the sight glass inlet site or something at the inlet to the sight glass rusts, e.g. some sort of metallic reaction.  The reason for my wondering is that the water in my sight glass becomes rusty and cloudy upon first boiler run of the season.  The boiler water, however, is quite clean and the boiler has been very thoroughly professionally cleaned by its original, steam-savy company after the last regular run in May.  The boiler is only 3 years old and did this in season 2 and 3.  (I think the boiler installers were there for something else in the first season at about the first boiler run, which I assume (dangerous) is the reason why it did not happen that year.).  Please note that rust inhibitor is added during the May cleanings.

If, after the first couple of days, the sight glass is removed, cleaned up and re-installed, the water is clear until gradually rust builds up in the glass over a couple of months.  It seems that days without boiler running particularly cause this, e.g., the months between the May cleaning and the Oct. boiler run.  Always the water at various drain points, e.g. lowest pipe drain, Hartford Loop drain, low boiler drain is clean or not very rusty.  Does anyone have an answer to this question.  One thing I know is tha the boiler is "sqeaky clean" at the end of the May servicing, yet this happens on first Oct. run.

crash2009

Weil Mclean also

My boiler is 6 years old.  My pipes are 110.  I replaced some of those old pipes this summer.  This is what I cleaned out of mine today.  It took me about 4 or 5 hours.  While it was running I flushed all the low fittings a few times.  Then skimmed for an hour.  Repeated that 4 or 5 times.  As you can see the garden hose is running clear, but the puddle in the gravel is all rusty at the bottom.  I am sure that if I repeat the process in 2 weeks I will get nearly the same results.  If you look close in the second picture there is a film of oil floating on the surface, I am still cleaning out the pipe dope and cutting oil from some new pipe replacement this past June.  If the water in your sight glass looks dirty, clean it again.  There must be a point where the pro's stop and say "That's good enough for now" 

SusanC

Experts-any idea re: sight glass rust in spring-cleaned boiler?

The problem is not that the boiler has not been cleaned thoroughly.  It was cleaned multiple times 2 1/2 years ago when installed and several times since then including each May; the cleaning has been done professionally, correctly and thoroughly. Water from drains is clean.  It's the sight glass water area that gets rust and I really think something in the sight glass inlet area either attracts the small amount of rust that would result over a summer even with rust inhibitor or there is some metallic reaction between the boiler and piping in that area.  Do any of you steam experts encounter this and/or have knowledge or theories re: cause and remedy?

Rod

Rust in the Sight Glass.

Hi- A certain amount of rust is normal in a steam system as air enters the system through the vents when the system cools.  When the boiler is cleaned, it was probably just the boiler that was drained and then filled back up resulting in nice clean water in the boiler (and sight glass) However, when you operate your system, steam goes up into the system. into the steam pipes, radiators and return pipes and this flushes a lot of old muck- rust particles,dirt etc. out of the piping and into the boiler discoloring the clean boiler water.



 If it is fairly easy to do,  Shut off electricity to the boiler and drain the boiler yourself. If possible also drain the wet returns. Refill the boiler with "new water" to the normal operating level on the sight glass. Then (and this is important!) fire up your boiler until it makes steam. There is dissolved oxygen in any "new  water" which can be VERY corrosive to your boiler. Bringing the "new water" to the boil drives off this excess oxygen. This should be done when any "new water" is added to the boiler!

Do you understand "skimming " and when you need to do this? Also do you have Dan's book -  "We Got Steam Heat" ?  It's a really good book for the homeowner . Humorous and easy to read.  Gives you a lot of information about your steam system and will save you a lot of headaches and money.

- Rod

http://www.heatinghelp.com/products/Books/5/61/We-Got-Steam-Heat-A-Homeowners-Guide-to-Peaceful-Coexistence

SusanC

Rust in Sight Glass - Probably Still Unanswered

Rod, thanks for your reply.  I don't think we have the answer yet though for several reasons.  And I do have "We Got Steam Heat," A Pocketful of Steam Problems," and "The Lost Art of Steam Heating," I understand skimming, have a lot of drains in under-water areas of returns as well as a drain very low in the boiler and know about the oxygen, system rust, etc.  The reason I don't think it's the muck from the pipes and radiators is that the sight glass water gets rusty early on in the first Fall run before much condensate even has a chance to return.  The people cleaning the boiler are professionals who do it right (and I am there for the whole process)  After cleaning they run the boiler for quite some time, checking the pressure cut-off and -in, etc.  Also they run some water from the drains in near boiler returns and they put a rust inhibitor tablet in the boiler at the end of cleaning.  As noted, if the rusty water is flushed out of the sight glass after the first few Oct. runs without further cleaning of boiler or pipes and the boiler is put back into operation and there is not a long gap as in summer, the sight glass water is fine.  Also if the water from the low boiler drain and drains in low parts of returns is checked, it is not rusty like the sight glass water.  It really does seem that the small amount of rust in the boiler either is attracted to the sight glass inlet or some metallic reaction occurs in the boiler/piping in that area.   Do you (or does anyone) have some additional theories, knowledge or similar experiences?

Rod

Dirty Sight Glass Water

Hi Susan-  Thanks for the info.on your steam knowledge.  I'm always afraid of overloading someone if I'm not sure of their steam experience. 

Interesting situation.  Is there any indication as to where the discoloration is coming from?   Are there any steaks that would indicate it was flowing down from the top of the glass?  It either has to come up from the bottom or down from the top and I  would think "down from the top" would be more likely due to the air exposure. What is the material used on the pipe nipples connecting the sight glass to the boiler? If you can't tell (paint/dirt etc), try a magnet as iron is magnetic and red brass/ bronze isn't. Red Brass /bronze doesn't rust so we're looking for something near the glass that is iron.  Or possibly something located on the boiler above the sight glass which would flow down the inside of the boiler and into the top hole of the sight glass.

These manufacturers are so cost conscious and will save a penny or two by using iron where they should be using bronze. Good example of this is the pigtail. Most come from the factory done in steel and therefore are prone to corrode and plug . This problem could be eliminated by using  bronze one which is only a buck or two more.

I'm not sure whether you can determine this - Is the discoloration in the whole boiler water or just that amount in the sight glass?   Please let us know what conclusions you come to,

- Rod

JStar

...

Do they clean just the glass itself or do they take apart the glass valves and clean the openings in the boiler? Those tiny tappings love to house rust and build-up. If you only clean the glass, the murky water will keep coming back forever, even if the boiler is clean.

crash2009

rust

I think we are all in agreement that mixing 3 dissimilar materials (iron, water, and air) are going to cause some rust.  That rust is inevitably going to end up in the boiler.  I think that a rust inhibitor should do what it's name says it does.  From what I have read, in this thread, the tablets are not doing their job.  What is the brand name of the rust inhibitor Susan?



It sounds like the tablets are keeping the water clean, but they are not preventing rust on the parts of iron that are exposed to air over the summer.  When you start the boiler, the water, bubbles, boils, and steams up into the iron inside the boiler.  This iron has a bit of rust on it from being exposed to the air all summer, and this rust washes off and appears in the sight glass.

TomM

pics?

maybe post some pics?

SusanC

rusty water in sight glass- I think we are getting somewhere

Thanks again.  What makes sense to me is that, whereas the rust inhibitor is preventing rust at and below the water line, as you suggest, it is not preventing rust above - not sure of brand but think it is Steamaster.  It makes the water a slightly purplish pink; we only use one tablet in the EG-40/45 because we don't want to get into surging.  It's possible that a tablet does not dissolve enough during the post-cleaning oxygen-boiling-off run of the boiler.  What rust inhibitor would you suggest?  Perhaps we should pre-dissolve tablet and/or use two.  All my connections (where I can see them outside the boiler) are brass; upon installation we changed the pigtail situation to brass and also soon raised it, as Weil-McLain has it coming directly and horizontally out of the boiler and not ideally elevated.   So all the sight glass metal materials that I can see are brass/bronze.  The rustiness is not coming down from the top of the sight glass; it comes in from the inlet.  The rustiness appears not to be in the rest of the boiler water as noted by the fact that water drained from the near-bottom boiler drain and low returns is not rusty.  If someone flushes the sight glass, we are fine for a long time, e.g. months.  So, now I am thinking it is coming from the above-water-line part of the boiler but somehow is being attracted to the inlet (not top) of sight glass.  The brass will coming through threads in the cast iron boiler.

SusanC

rust in sight glass water reply re: tappings

I seem not to be able to reply individually to different responses:  Crash2009 re: cleaning tappings, they take glass valves apart and clean tappings and replace sight glass washers and re-install glass.

See response to Rod for rust inhibitor info.

SusanC

Re: rusty sight glass water and rust inhibitor

Wasn't able initially to respond to your entry individually.  Now can, so please see response to Rod for rust inhibitor info. Sorry.Reply Edit

crash2009

Rectorseal / Steamaster

Was it a tablet with blue dots?  If so, Here are the directions for using it.  New systems use 4 tabs per 100 square feet of radiation.  Older systems 6 per 100.



INSTRUCTIONS

READ ALL DIRECTIONS, MSDS AND WARNINGS ON LABEL BEFORE USING

FOR CLEANING VERY DIRTY STEAM BOILERS WITH EXCESSIVE SCALE, RUST AND SLIME:

• 6 tablets for each 100 sq. ft. of radiation, 25 MBH or .25 GPH nozzle rating, or until water turns violet.6 tablets for each 100 sq. ft. of radiation, 25 MBH or .25 GPH nozzle rating, or until water turns violet.

• Drop tablets into any convenient opening. Allow to steam for ½ to 3 hours, then drain and flush.Drop tablets into any convenient opening. Allow to steam for ½ to 3 hours, then drain and flush.

• Refill boiler and add 4 tablets for each 100 sq. ft. of radiation to act as a rust inhibitor and conditioner. LEAVE

THEM IN.Refill boiler and add 4 tablets for each 100 sq. ft. of radiation to act as a rust inhibitor and conditioner. LEAVE

THEM IN.

FOR MAINTAINING CLEAN, RUSTFREE WATER AND FOR NEW INSTALLATION:

• 4 tablets for each 100 sq. ft. of radiation, 25 MBH or .25 GPH nozzle rating, or until water turns violet.4 tablets for each 100 sq. ft. of radiation, 25 MBH or .25 GPH nozzle rating, or until water turns violet.

• Drop them in. LEAVE IN. Conditions water for full season.Drop them in. LEAVE IN. Conditions water for full season.

FOR HOT WATER SYSTEMS:

• Use 4 tablets for each 5 gallons of circulating water or until water turns violet.Use 4 tablets for each 5 gallons of circulating water or until water turns violet.

• Stops corrosion and stagnant odors.Stops corrosion and stagnant odors.

For additional technical information, call Toll Free 1-800-231-3345

SusanC

rust inhibitor instructions

Thanks for instructions.  I do believe we should use more than one tablet.  According to my boiler people, however, the number of tablets recommended in the instructions does sell a lot of rust inhibitor but would cause excessive surging.  We probably will compromise but not use as many as in instructions.  Also note that the boiler and return water is good; it's mainly the sight glass water that is rusty.

crash2009

Thank-you!

Susan, Did you call that Toll-free number to get the Steamaster opinion?  I know they want you to continue using their product.  I am sure they will come up with a solution to help you acheive what you want........



As I understand it, our boilers are just a big cast iron pot with a few holes in it.  Those holes allow the water to come in, and the steam to go out.  There are a couple more for skimming and flushing, 1 or 2 for the pigtail, and the 2 for the sight glass.  The product that has been used on your system Rectorseal Steamaster forms some kind of a chemical re-action with the rustable metal inside the boiler and pipes.  (as I perceive it, kinda like a Teflon coating in a cast iron frying pan)  This coating appears to have worked in the majority of your system, but not in the passageways for the sight-glass.  Next time you have the sight-glass off, get one of those little inspection cameras (home depot $30)and have a look in there.  You might see the reason, there might be a little chunk of something that continues to rust even though rust has been prevented all around it.  Good luck and thanks for the education, I never would have read about Steamaster without your suggestion.  It looks like a good product that I may try some day.   

nicholas bonham-carter

old rusty

i get that rust discoloration in my sight-glass as well, but so far a dismantling, and cleaning with a narrow bottle-brush will make the glass clear for at least a couple of months.

it is possible that the glass itself attracts more rust than any other part of the boiler. maybe there could be electric current leackage from the LWCO which could cause this.

i prefer this glass-cleaning routine to the use of any sort of additive, as i believe the steam is better with just pure water.--nbc