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Question Regarding PigTails & Gauge Glass

Hi!

My steam pressure gauge is reading 2 and a half or so, which, as I've gathered is a little high. The pressure is not going down much after the burner is off, so I'm assuming I need to unclog, or replace the pigtail. My question is whether I need to use a certain type of plumbers tape or not - the stuff that the service guy used (several years ago) is blue -all I have is white, so I'm wondering if there's a difference whether the blue has a higher rating for heat or not.

Also - I just replaced the gauge glass - but the water inside is fairly dirty, and leaving residue in the glass (even after blowing it down a few times). I'm not sure if that's an issue, or if I should skim it off. The skim plug looks like it hasn't been touched in the 40+ years that the furnace has been in, and there's putty stuff around the edge of the plug, so I'm not sure what it is....

Also Also, - the new gauge glass tends to show condensation over the water level (and all the way to the top). When I installed it, I raised the glass it up a bit via the washers, so it sat (what I thought) was in the middle. I'm wondering if it's set too high, and/or whether I need to lower it - or whether the pigtail issue has something to do with this.

I'll post some photos. Oh - and if someone could let me know if the marks I made on the gauge glass rods are ok for high & low indicators. My Dad always said to keep the level just below half on the gauge glass, but I've seen people have them nearly filled, and I've also seen some where it's been really really low...

Thank You!

Marcus

Comments

  • BobC
    BobC Member Posts: 5,312
    That pressure gauge is probably shot, consider adding a 0-3 PSI gauge to the output of the pigtail AFTER cleaning or replacing the pigtail.

    Signs of condensation in the upper part of the gauge glass usually indicates oil in the boiler water. I would flush that boiler out to get rid of as much muck as you can, has the LWCO been taken apart and cleaned recently? Once the water in the boiler is clean the boiler should be skimmed a few times to get rid of any oils in the system.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • marcusjh
    marcusjh Member Posts: 79
    Ok- flushing: does that entail removing bolts and plate and squirting water in to wash it down inside or does that mean just emptying and re-filling the tank?

    No idea about the lwco. Someone suggested pink plumbing tape- but is that too thick?

    Thanks!
  • BobC
    BobC Member Posts: 5,312
    It means opening the drain valve at the lowest point on the boiler and allowing all the water to spill out, you should also open up any drain on the wet return and drain that.

    Then close both valves and refill the boiler (if the boiler is hot this should be done very slowly). If the water was really dirty, the boiler should be drained and then refilled again. Next run the boiler up to steam to purge any oxygen.

    The thicker tape is about 6X thicker than the cheap thin stuff. Any type of teflon tape will do but it will take more wraps of the thin stuff to seal the connection reliably.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • JUGHNE
    JUGHNE Member Posts: 9,824
    To help fuel your obvious interest in steam boilers I would recommend a book from the "Store" above. Start with "We've got Steam Heat", there are at least 2 more good ones. Great entertaining reads. I've got them all.
  • marcusjh
    marcusjh Member Posts: 79
    Yup- ive gotten more fascinated than i ever thought i would :)

    Regarding the flushing & skimming- I assume i should do that before replacing the pigtail?

    I've no idea how to take apart the lwco- is that covered in the course books? :)

    Thanks everyone- so glad there is a place to go for help.

    Marcus
  • JUGHNE
    JUGHNE Member Posts: 9,824
    Clean the pigtail and those fittings first. Remove the pigtail and make sure the top of the Lwco is clean. Also the inlets of the p control and gauge need to be clean. Prime the pigtail loop with water, this protects both from being in contact with steam.

    Download the installation and repair parts info for your model and number of your Lwco. This will give you an idea of what is inside.
    When you flush the Lwco, does the fire shut down.
  • marcusjh
    marcusjh Member Posts: 79
    Thanks - got anoher question- not sure if i will need to skim or not, if so.... Is it possible to turn off the bottom valve, remove the sight glass, and use the upper outlet from that to skim from? The actual skim port looks like it's melded shut with either cement or asbestos rope couldntell).
  • JUGHNE
    JUGHNE Member Posts: 9,824
    When you say "skim port" are you referring to the pipe plug in the center of the steel plate that has the 6 bolts. Someone else here would be familiar with using that opening. I believe that is for a hot water heating coil. But that plug would probably be the easiest to remove from a boiler this old. I would leave the 6 bolts alone. The pipe dope around that could scrape off with a pick, I cut it away with a dental type pick to get the first threads exposed. Then several applications of some type of rust buster. (I have had good luck with PB blaster......strong smell though...Kroil by Aerokroil smells better and might work better). Some hammer tapping on the plug after each application. Over a period of several days if possible.

    But wait for more advice from someone familiar with this particular boiler design.
  • marcusjh
    marcusjh Member Posts: 79
    No - I mean the plug in the center of the furnace at the top, which I believe is where you're "supposed" to skim from - according to the directions that I found (my Dad never threw anything away).

    Is there any reason not to skim from the top of where the gauge glass goes? Or is that just a vent that won't allow water to come through? I thought I had posted a photo or two with my last comment, but I guess not... I'll see if I can upload them again via my phone.

    Thanks again -
  • BobC
    BobC Member Posts: 5,312
    The top gauge glass port will work but because it's a small port it will take a lot longer to skim through. One of our members came up with a very good idea; take a pipe cap and mill or saw a slit through the center of it's face to get a wide slit that makes skimming much faster.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • marcusjh
    marcusjh Member Posts: 79
    Gothe pigtail clean.... Wow... black clouds in the vinigar... Thinking about going to hdw store to get a 90degree and short pipe to skim with off the gauge glass top so i dont haveto use a tiny bucket. There was an ugly brown head on the new water that filled the boiler.

    I'm tapping on "attach file" with my phone, but nothings happening, so I'm guessing my phone is too old to upload photos to the site.

    Oh- when i ran the furnace- the pressure gauge never moved in the 45 minutes it ran. Top of the pigtail was cold, bottom was hot... -normal? Inside pressuretrol was seto 3 when i opened it, outside seto .5. Five bedrooms, large main floor (9ft ceiling).

    Thanks!
  • marcusjh
    marcusjh Member Posts: 79
    If I accidentally reversed the wires would that make a difference?
  • Abracadabra
    Abracadabra Member Posts: 1,948
    marcusjh said:

    If I accidentally reversed the wires would that make a difference?

    on the pressuretrol? no
  • BobC
    BobC Member Posts: 5,312
    Did you check inside the base of the pressuretrol to make sure the little hole at the base is clear?

    The dial on that pressuretrol should be set at 1 not 3 and the the main (on the front) should be all the way down.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • marcusjh
    marcusjh Member Posts: 79
    I have not checked the pressuretrol - however, now my pressure gauge has moved into the negative (just to the left of zero).... I read something about a vacuum happening after flushing - is this what happened? What do I do?
  • Fred
    Fred Member Posts: 8,518
    There is a slight vacuum in the system. You don't need to do anything. It should return to 0 when the vents open
  • marcusjh
    marcusjh Member Posts: 79
    The pressure gauge is still leaning slightly left (still ON 0, but sitting on the left curve of the 0), doesn't move during the burn at all - I'm guessing it's because there's no pressure. Takes about 40 minutes for the heat to come up in the house. If I were to plug every vent on the radiators (or shut them off), would it move? -Not that I'm going to do that - but I'm just curious as to whether it's supposed to move because of back-pressure from the system or not (yes, I know, I should get the book, but $ has been tight lately). Pig tail gets hotter now than it did when I first re-installed. Oh, that reminds me - wouldn't the water have evaporated out of the pig tail - or does it replenish due to condensate?

    The gauge glass is still wet on top, so I know I have to skim. It's been in the 20's the last few days, and I didn't want to take the chance. Bottom half of the glass is dirty water - so I may need to flush -again.

    Thank you!
  • Fred
    Fred Member Posts: 8,518
    Mine doesn't move during a normal heating cycle either. That's a good thing. If you try to recover from a 2 or 3 degree setb ack, the boiler will run long enough that you may build a couple ounces of pressure. Pigtail loop will stay filled with condensate. Sounds like another skim or two may be necessary.