dirty sightglass

ChrisJ

I think I'm going to start having nightmares about skimming.



My sightglass keeps getting a rusty film above the water line.  I clean it by opening the bottom valve and draining it into a bucket.  I then leave only the top valve open to use steam to push the crude out.  It will stay spotless until it runs again.



Is this a clear indication that I still need to skim more or is this actually normal?  The last two times I skimmed it was hard to tell if I was getting any oil out or not and I don't want to keep running fresh water through the system if I don't have to.  Close up it looks like a thin film of rust on the glass, no chunks or mud.  It moves up and down freely with the water line.

MotownSteamer

How about just skimming from the top

Any particular reason for draining from the bottom first? And I'm not sure skimming under steam is a good idea. Hot water yes, but not when steaming.



I'm not an expert, but I skimmed for 4 days after the new boiler was installed. All from the top, just at a trickle for a couple hours each night.

ChrisJ

skimming

I wasn't skimming from the sightglass, that was only cleaning the sightglass.



I skim through the large 1 1/2" valve to the right of the sightglass. I do it slow enough that it takes 40 minutes to almost fill a 5 gallon bucket.

crash2009

Chris,

 now that you got things rockin and rollin, you have been cleaning the pipes in the entire house.  All the crap from all the years of not working right is building up in your wet return, then hopping over the hartford and back into the boiler.  Drain a little from the wet return and figure out how to do a backflush.  http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping  More skimming as well.

ChrisJ

wet return

Hi Crash,



The last time I drained some from the wet return it seemed like it was pretty clean water. 

I've already skimmed 5 times and probably removed a total of 40 gallons of water.  I kind of wondered if I had skimmed too soon but I had no way of knowing exactly how long it took for all of the oil to wash down out of the new piping and what not.

I'm going to assume the sight glass is normally clean above the water line?

Rod

Blowdown Valve

Hi Chris- It might be a good idea to install a sight glass blow down ball valve.  Get a 1/4 ball full port ball valve and a pipe to male garden hose adapter. Gordo gave a great suggestion to use a old washing machine hose as a lead off to a drain or bucket. 

You're probably going to see a bit of crud for a while as your new boiler is a lot more "energetic" than the old one and this is removing the crud from places in the system that the old boiler didn't. With the installed sight glass blown down valve it is much easier to keep the sight glass clean with weekly blow downs. Over time your boiler water will clear up. Adding fresh water is okay as long as you boil off the dissolved oxygen.

- Rod

ChrisJ

sight glass valve

Hi Rod,



I've wanted to install that setup on the sight glass ever since Gordo and steamhead posted pictures of it.  Unfortunately money has been very tight for a while now so I need to wait for a bit.



Do you think I should just keep cleaning the glass, or should I do another skim tonight?  I never completely drained the boiler and "rinsed" it as Weil-Mclain said to, not sure if I should or not?  



I should also mention when I had the drain open on the sight glass and only the top valve open I was getting small bursts of liquid as well as steam.  Not sure if this is due to it needing another skim or if its normal. 



I was thinking about doing a skim when I get home tonight.

Rod

Dirty Water

Hi Chris- Just having dirty boiler water doesn't necessarily mean you have to skim. As an indicator for the need to skim I usually go by how much bounce there is in the sight glass and also whether there is moisture forming in the sight glass above the waterline. If it is extensive, "slop over" into the sight glass, it can be a sign that you need skimming though it sounds from  the occasion "slop over" you are experiencing, that it is normal.



Skimming just removes the oil contamination that causes increased surface tension, it doesn't clean the boiler water. Except in a dire contaminated boilerwater situation, flushing boilers is a warmer weather excercise so I'd be inclined to wait till spring to flush.

 Since it wasn't done at start up I would be inclined to do a couple of complete boiler flushings. When the boiler is stone cold, fill the boiler till just above the waterline and then drain it out, close the drain valve and fill and drain it again and then on the third time  just fill it to the waterline and bring the new water to the boil.   After a few days if the water gets dirty again, repeat the process.  You may or may not have to skim again at this point.

- Rod

ChrisJ

hot or cold?

Rod,

This may be a stupid question but I'm going to ask anyway.



When I skimmed I noticed if I fired up the burners and got the water good and hot a lot of foam would start coming out of the skimmer even after I shut the burners down.  I wasn't sure if this indicated oily water or if it was simply surface water with some steam \ air trapped in it.  Like I said I had a hard time telling if I was getting oil out or not even with a flashlight.  Most of the time the water just appeared rusty brown.

I only noticed this after getting the water good and hot. I tried cold skimming mostly as I noticed a lot of guys think the burners only stir it up. 

Abracadabra

pH

check the pH of the water

Rod

Cold & Hot Skimming

Hi Chris- Being a homeowner and not a pro, I haven't had all that much experience  skimming a wide variety of boilers so I haven't really figured that out whether hot or cold skimming is better myself. I can see benefits to both approaches so I usually do a combo of the two.

I first flush out the boiler  and wet returns using the bottom drains as best I can through multiple fillings and emptyings. Since I'm starting with a stone cold boiler I then do a high water volume flow to float out any surface contamination via the skim port.    Since the boiler is cold there is no chance of cracking it by adding high volume cold water. I then let the boiler water settle a while and then do a s-l-o-w "cold skim". (My feeling is that with the water being cold, the oil is more viscous and is more likely to stay on the surface of the water.) I then shut off the incoming water and turn on the boiler and heat the water till it is about to make steam. As my experience is that the boiler water is more turbulent with the burner firing so I shut it off before the burner off before I start to skim. Skim really s-l-o-w-l-y and restart the burner when the boiler water cools off. I think the advantage to the hot skim is the heat will cause any oil on the inside metal surfaces of the boiler above the water line to flow down to the surface of the water so it can be skimmed off.  You then may run the boiler a couple of days and see what the operation of the system shakes out. If necessary, all I usually have to do is just another hot skim.

The first time I skimmed I had to skim 5 times as I hadn't cleaned the inside of the new pipe before installing it. Since then I can usually get by with two or three skimmings. I've never tried a single continuous skimming, that is, multiple buckets over several  hours. I usually just do a single 5 gal bucket over about an hour and then skim again the next time I have some free time, usually a day or two later.

- Rod

ChrisJ

skimmed

Spent 5 hours tonight skimming and think I actually noticed a big difference.  During the skimming whenever I would fire up the burner as it approached boiling I would notice tons of groups of small bubbles coming out.



Well the final skim when I fired up the burner I didn't see anything even close to this.  I in fact got very close to steaming and no little bunches of bubbles.  My guess is that was oil trapping steam and carrying it out the skimmer.



This may be the cleanest this boiler has been since I finished installing it in November. 



Here is a picture I just took after a long run and 4 degree increase.  It actually tripped the LWCO after I turned it off.  I knew I was going to end up runnig out of water before it would ever go off on pressure   There is still a touch of oil film in the glass I haven't gotten out yet.

crash2009

Dan's video

Chris, you spent all that extra money on king valves and the hartford valve.  Those valves were suggested to help you prevent the crap from getting into the boiler in the first place.  Its a brand new boiler.  That crap isn't coming from the boiler.  Its coming from the house.  Its in your return.  Close the kings, pressure up to a pound, and spit the crap out the return.  Could you watch Dan's video.  He will explain how to do this.

ChrisJ

Dan's video

Crash,  I've watched the video many times even before I did my piping.



The garbage in the boiler was a mixture of rust and oil and maybe some junk from the rest of the system.  I'd guess the majority of the oil came from the new piping and the rust is probably from the new piping and boiler.  Keep in mind a brand new block will most likely produce a lot of rust in the beginning because the iron has absolutely no protection from it.  A used block should have a pretty good protective coating of rust on it.



Of course I only have this as a theory as I have no prior experience with it.

I drained some out of my wet return last night and just like previous times it was clean water.  I did do one blow down at around 3 PSI a while back and nothing came out of the boiler drain.



I had another look this morning and the sight glass is still very clean with the slight bit of oil on top of the water as shown in the picture in a post below.  I don't think I ever really got the boiler clean with previous skims and every time it ran hard more oil got washed down.

crash2009

I could be

completely wrong.  My suggestion was to remove the oils before they get to the boiler.  When you open the drain valve of course it will be clear, unless you have some sediment.  Drain some and put it in a glass jar, you might see the oil floating on top.  I havn't tried to steam the return yet, but I have read about the process.  The process appears to be an instant fix. 

ChrisJ

steaming the return

Do I need to install valves where my dry returns drop down to the wet returns?  I'm assuming I would need to in order to build pressure in the wet return.



I've considered installing the valves as I actually have half of what I need to do so.

crash2009

I have to go to work now

Watch the video again.  You did install the hartford valve, didn't you?  If so that's all you need.

ChrisJ

Hmm

Crash,



If what you are thinking is true that would mean some oil is going to end up in the boiler again from the wet return.

I think I'm understanding what your saying now.  The picture you posted helped alot thanks.

ChrisJ

PH

Should I still check the PH even though the problem was oil?



If so, is there an easy to find affordable solution?  I can't do a $80 water test at this time.  I'm using city water that if it matters doesn't taste too bad.

crash2009

Here is a better diagram

I thought you installed the hartford valve when you installed the kings.  As you can see the skimmer can only remove the oil from the boiler.  Since that oil originated from the other side of the hartford, and farther, the oil you see in your sightglass will return again and again.  If you open the kings, close the hartford, pressure up the system, and open the drain valve, steam from the boiler will steam clean the return.  You will need to find out how to do this safely.  after the condensate is gone you will have full blown steam coming out the drain valve. 

Watch the video again and develop your own procedure.

ChrisJ

yep

I installed the valve in the hartford.

I'm at work so cannot watch the video right now.  But from what I recall Dan just mentions wasting the condensate.  He doesn't specifically say how.

crash2009

This is one reason why

we spent the extra time and money to put these valves in.  If the boiler ever gets dirty on the bottom (with sediment) King/Hartford valves can be used for that as well.  Close the kings and the hartford, pressure it up, and open the boiler drain.  All the crap gets spit out.  The first time is a little un-nerving.  Be safe not sorry.

ChrisJ

pressure?

Why does it seem like everytime my boiler needs skimming it runs at higher pressures to do the same work?



Several times now when it was getting bad I would notice the boiler would sound louder while running and I would build pressure, maybe 0.5PSI or slightly higher.



After a good skimming it boils much quieter and I build an ounce or less of pressure even during a recovery..  What gives?   Why would an oily film / wet steam cause the whole system to run at a higher pressure or are the two not related and its just a coincidence?

ChrisJ

proof I am not crazy

I took this early this morning during a 2 degree recovry while it was 20F outside.



Notice the low water level in the sight glass and the 0 PSI on the gauge.  While the boiler was dirty I wouldve been above 0.5PSI by this time.  Most radiators were heated all of the way across when I took this picture.  This was near the end of the 2 degree recovery.

Hap_Hazzard

Not sure about the pressure

But the noise results from the steam bubbles needing to be larger to break free at the surface. This is the same reason you see all that surging. I suppose this also means that more vapor pressure is required to produce steam, so that might explain the pressure, but I'm not really sure.

Abracadabra

pic of near boiler pipiing?

pic of near boiler pipiing?

ChrisJ

piping

Two pics, one before insulation and one during. I have a little more insulating done now but not much.



two 2" risers which are 35" up from NWL. Header is 3" and equalizer is 2". Its hard to tell from the picture but there is a fair amount of pitch on the header. For example the 2" nipple going down into the header from the boiler closest to the camera is actually a 1/2" longer than the other.