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steam traps

brycebryce Member Posts: 8
hi everybody, first post ever and i'm sorry if i'm repeating the topic of many posts before me... but... i'm having many issues with my steam system, one of which is inconsistent heat or no heat during the burn cycle to some of the radiators. the steam traps on the return lines coming from those same radiators all happen to be painted and look like the picture i've posted. any thoughts on whether the outside needs to be cleaned in order for them to work? do they need to be replaced? or can i do without them all together? many thanks.


  • SteamheadSteamhead Member Posts: 11,335
    Those are not traps

    they're check valves, which only allow flow in one direction.

    Can you take a picture showing how they are hooked up to the rest of the system?
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • brycebryce Member Posts: 8
    How it's hooked up... i think

    the valve is in the far right of this image. each radiator has one on their return line, that meets a larger return line, that runs around the bottom of the basement, catching all as it runs back to the boiler. 
  • SteamheadSteamhead Member Posts: 11,335
    Do the radiators

    have shutoffs on both ends and an air vent? 
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • brycebryce Member Posts: 8
    shut offs ?

    Last post should have happened an hour ago, sorry. Each radiator has a shut off on one end of the unit itself, and a steam realease valve on the other. Is that what you mean?
  • RodRod Posts: 2,067
    Need Pictures

    Hi- Welcome to the Wall!

    Take some pictures of your boiler and the piping around it from farther back so that we can trace where the piping goes. We can blow up the pictures if we need to see more detail. Also take a picture of one of your radiators so we can see both ends. If you can't get both ends in the picture then take a separate picture of each end of the radiator so we can see the piping and what is attached to the radiator.  What we are trying to do is determine what type of steam system you have as there are quite a few variations. Don't worry about asking questions. That's how we all learn!

    - Rod
  • SteamheadSteamhead Member Posts: 11,335
    I bet it's

    a one-pipe system where they dripped the ends of the runouts. Does the small line with the check valve come off the bottom of the vertical pipe that goes into the rad's steam shutoff valve?
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • brycebryce Member Posts: 8
    edited November 2011
    From farther back

    i have a couple cast iron radiators that have one pipe, and many other radiators that have fins and two pipes. all have a vertical pipe coming to the basement where it turns towards the wall of the basement, comes down, meets the valve, then turns again to meet the larger return pipe that makes its way around the perimeter of the basement and back to the boiler. the smaller pipe that has the valve comes from the return side of each radiator. also, all radiators have a varivalve on the end with the return. that was the first thing we replaced when we moved in a year and a half ago. that's a separate issue all together. maybe that'll be my next question... i've tried to step back a little, but i'm not sure if the pictures are any better. also, i've included a pic. of the unpainted valves that are coming from radiators (and the cistern) that seem to heat more regularly. thanks guys.
  • RodRod Posts: 2,067
    Need More Pictures

    Hi- Thanks for posting the pictures as it gives us a much better idea of your steam system.

    What we need now is some pictures of the steam piping.  Take some pictures of the the piping connected to the top of the boiler including the piping it connects to above the boiler near the ceiling. How many steam mains do you have? (The mains  are the large pipes above the boiler which distribute steam to the smaller pipes connected to the radiators)

    at the end of each main there should be what is called a main vent. This looks like a bullet pointing straight up or a can of tuna on its side and is connected to the main. See if you can locate these and post a picture. Again you can take the pictures farther back a bit (if possible) and we can blow them up.

    Other questions:

    When your system is running, what is the maximum pressure on the steam gauge?

    (Residential steam system are designed to run at maximum pressure of 2 PSI and ideally most run lower than that)

    Does your boiler need to have water added very often to it?

    All all the radiator working or just some of them?

    Which ones aren't working- the cast iron or the fin tube?

    From what I can see so far, your return piping in which the condensed steam (water) returns to the boiler is rather substandard. The "traps" as Steamhead  mentioned, are one way valves and really have no purpose in the system. I imagine that they were installed to make up for other short comings in the system. The Vari- valve vents aren't the idea vent to use and usually are used as a last result to try to overcome other shortcomings in the system.

    I might mention that there are some very good books on residential steam heating in the shop section of this website. You might want to get a book called "We Got Steam Heat!"

    Here's a link:

    This book is written for the homeowner new to steam. It's easy humorous reading and in an evening or two you'll know much more about residential steam systems. With pictures and diagrams it explains how you steam system works and what all the components operate.  A very worthwhile book which will save you a lot of money.

    - Rod
  • brycebryce Member Posts: 8
    edited November 2011
    some answers, pictures to come...
    • how many steam mains do you have? 2

    • as of yesterday there was only 1 main vent (if you can call it that), it was just another varivalve at the end of oone of the mains. the end of the other main was capped. i met a guy yesterday who cam out and looked at the setup, who told me about this site, and we put a extra varivalve that i had on the end that was capped.

    • the pressure on the boiler is set at .5, yet the gauge is way too big to notice any change in pressure.
    • Does your boiler need to have water added very often to it? no, yet it's manual feed, and seems to be feeding a little backwards.

    • All all the radiator working or just some of them? they will eventually all work, if the thermostat is cranked, but during a standard burn time, they do not all heat up. looking into a programable burn time... ?

    • Which ones aren't working- the cast iron or the fin tube? fin tube
    • as for the books, i'm incredibly interested and will be buying many.
    • as for the valves, is there any reason why the radiators that are slow to heat, return to the painted valves? is there any good in taking them off and replacing with a union? pics. to come, and at this point i might as well share the rest of my issues in the next post. thanks again! 


  • brycebryce Member Posts: 8
    some more pics.

    i'd rather not take of the insulation off if i don't have to, but if you need to see the pipe, i will. i do know that it's copper coming off of the top of the boiler, which i've already been told will eventually need to be replaced. also, i get wet steam, and sometimes lots of water, coming out of the varivalves on some of the radiators, and have been told that i need some sort of chest/overflow above the boiler. also, the manual feed doen't seem to be going into the boiler at the right spot, but rather into the return lines. and lastly, i was told a gorton #1 and #2 should be used as my main valves asap. those are just a few of the observations i've had.
  • RodRod Posts: 2,067
    Great Pictures!

    Hi - I was in the middle of replying to you when your last post came up so will now look at the pictures first before replying. Great pictures BTW. They really help!  Will try to get back to you later this afternoon or evening. Wife has chores planned out for me!

    - Rod
  • RodRod Posts: 2,067
    Steam System Problems

    Hi- The pictures really helped out.  From your remarks it would seem you already have a pretty good idea as to what the problem areas are.

    Main Venting - Unlike Radiator vents, you can’t have too much venting on your mains. The idea of large capacity main venting is get the air out as quickly as possible so that the steam can reach all the radiators quickly. If you lack good main venting, the radiators take a long time to heat and the distribution of steam isn’t very good. Some radiators may not heat at all.

    The first thing I would do is fix/increase your main venting.  If you can give us the pipe sizes of your mains and their  approximate lengths we can calculate how much venting capacity you would need. ( I’ve attached a pipe sizing chart below. Measure the circumference of the pipe and compare to the chart)

    You want to use proper main vents like a Gorton #1 or #2 or a Hoffman #75. Unlike the Vari-valve, they have a float which stops water coming out of the vent and are designed to be used as main vents. All three are available from Pex Supply on the internet or at you local supply house.

     Here’s a link to Gerry Gill’s website which has a lot of good steam information on it.

    Gerry Gill, a Cleveland steam pro, is an expert on steam systems and venting.

    Radiators- On one pipe steam system you want to normally operate with the radiator valve fully opening. In the case of your fin tube radiators since they have a drip line you maybe able to throttle them a bit. On the cast iron radiators the valve on the inlet steam pipe must be fully open.

    Also using a carpenters bubble level, make sure the radiator are very slightly sloped towards the inlet pipe as this “encourages” the condensate to flow out the radiator back to the boiler.

    The fin pipe radiators need to slightly slope towards the drip end of the radiator to encourage the condensate to flow towards the drip pipe.

    Radiator Venting - On the fin tube radiators I would remove the Vari valves and use a Hoffman # 41, which is a  convector valve or if you’re on an economy budget, a bronze street elbow and a Jacobus Maid -O-Mist # 4 (check there is room for this)   Keep in mind, with steam related equipment, you get what you pay for quality wise.  Using large capacity radiator venting , like the

    Vari-valve, on a radiator especially like a fin tube, while it sounds like good idea at first, but can create a large volume of condensate which slows down the steam flow. There is an old steam adage: “Vent your mains quickly and your radiators slowly!”

    Returns - You have returns from the end of your mains and returns (“drips”)  from your fin tubes.

    These should all drop individually into the Wet Return.  They should not join and other pipe until are in the Wet Return (that is below the boiler’s waterline level.

    Definition - On the return piping it is know as the “Dry Return “ above the boiler’s waterline and the “Wet Return below the boiler’s waterline even though it may be the same pipe. Since the Wet Return is below the boiler’s waterline it will be filled with boiler water.

    Wet Returns because they are the lowest part of the system tend to collect all the dirt in the system and overtime this dirt along with corrosion plugs up the wet return if it is not regularly cleaned.

     The pipes on your wet return are rather small and the way they are laid out probably have collected a lot of dirt. Usually it is a lot quicker / cheaper to just replace them than try to clean them out. Above the boiler’s waterline level they should be fine.  If condensate is returning to the boiler reasonably well at this time replacing the wet return can wait till springtime and warmer weather.

    Installed one way valves (“ the Traps”) -These aren’t necessary and should be removed.  For now maybe you could see if your can just open the tops and remove the swinging gate. As mentioned earlier these drips should drop straight down into the wet return. As they are now, the horizontal section may be collecting dirt which causes the condensate to back up.

    Books- You mentioned getting books. If you do so I would recommend you read in this order  “We Got Steam Heat !” first and then “Greening Steam” and after that “The Lost Art of Steam Heating”

    These are all very good books and you will soon be able to understand and evaluate what further  needs to be done to your system as far as the piping on the boiler is concerned.

    If you need services of a steam pro, take a look in the “Find a Contractor” section at the top of the page . There are some very good guys listed there.

    - Rod

  • brycebryce Member Posts: 8

    the main pipe size is 2 1/2". the mains measure about 23' and 35'. one of the last questions i have for the moment is: what would be the best way to clean the wet returns, if this is the route i wanted to take? thanks so much for everything rod. you are a steam genius! as a beginner, can i tackle these things myself? all the pipes seem to be really rusty? any suggestions before i set a wrench? thanks again.
  • RodRod Posts: 2,067
    edited November 2011
    Vents Sizes

    Hi - Here are the calculations for your Main Vents- 

    One lineal foot of  2 ½ pipe contains  0.03 cubic feet of air.

    Long Main - 35 ft x 0.03 = 1.05 cubic ft.

    Short Main- 23 ft x 0.03 = 0.69 cubic feet.

    Venting capacity @ one ounce PSI pressure.

    Gorton #1  -        0.330  cu. ft.  per minute

    Gorton #2  -        1.100  cu. ft. per minute

    Hoffman #75  -   0.500 cu. ft. per minute

    I think I would use a Gorton #2 on each main. The target is to vent your mains in a minute or less.  Quick venting saves fuel as steam arrives at the radiators faster.

    Using a Gorton #2 on the shorter main might be a bit of  “over kill”  but I think it would be less hassle than stringing several  smaller capacity vent together and you can’t “over vent”. It looks like one of your present “main vents” is on ½ pipe which is okay as ½ pipe has the capacity to support 2 Gorton #2 vents . On the long main you’ll have to remove the present vent and put in a new ½ reducer bushings plus some new 1/2 inch vent piping.  The vents must be installed so they are vertical and also you want to install them so that any water reaching them will drain back to the main. Get your main venting acceptable first and then tackle the radiator venting. When you get your new main vents installed let us know how they preform.

    Since I have the venting book out, I’ll also include the vent capacity figures for the fin tube and radiator vents I mentioned in my last post.  BTW I might just mention that these venting tables are included in the book “Greening Steam” and are also available in the book “Balancing Steam Systems”.

    Radiator Vents  - These figures are also at a venting capacity @ 1ounce PSI pressure.

    Fin Tube Radiators

    Hoffman 41 (convector vent )    0.058

    Maid -O-Mist # 5 (angle vent)   0.100

    Cast Iron radiators  

    Hoffman 40                                0.042

    Hoffman 1A (adjustable)           0.020  - 0.145

    Cleaning out the Wet Return

    As I mentioned in my last post depending on the physical condition of the Wet Return is may be easier to just replace the piping rather than try to clean it out. This is especially true when the wet return is old iron piping. Copper is a good replacement on the Wet Return and should probably be of 1inch pipe.  Copper piping shouldn’t be used on for steam piping but is okay to use on non steam piping like the Wet Return.

    There is lots of good info on steam in the area which is known as “Off the Wall in the “Resources” and “Systems” sections at the top of the website page.

    Here is a good article from there on cleaning Wet returns.

    All that I have learned about steam has come from Dan’s steam books and the generous sharing of knowledge from the pros on the Wall. I’m just passing along what they have taught me.

    - Rod
  • brycebryce Member Posts: 8
    edited November 2011

    thanks again for everything. buying "we got steam heat" right now.
  • Patrick McGrathPatrick McGrath Member Posts: 54
    I met Bryce the other day

    Hi guys:

    I met Bryce the other day at my sister's store.  I ran over to his house to look around for him, and I gave him my pro's name as well as the heatinghelp website.

    It looks like someone changed out the old cast rads for the fin-type ones at some point.  The two pipe arrangement is similar to the hybrid system that I have on my one pipe system - the one way valves were new and different (I had no idea what they were...guessed traps...I am a one trick pony when it comes to this stuff).  The rads that were not heating quickly had completely painted pipes, and it was texture paint.  I figured if they were traps that the paint was a problem.

    Bryce also has a newer dial-type Honeywell thermostat.  I don't think he is getting one cycle per hour, so the system isn't heating all of the way.  I told him about the touchpad Honeywell that you guys suggested that I purchased to alleviate the issue.  I think you can get them for about $110 on pexsupply.  I just looked at mine, but it doesn't identify itself - if you can pass that on to him it would be great.  When we jacked up the system and got a long burn, the house warmed up nicely (of course, save for those three rads with the painted pipes).  We did about a twenty minute fire.

    I suggested a Gorton one on the short main, as it is extremely close to the boiler in relation to the long main's vent.  As well, clearance is an issue, potentially on both ends.  His basement is like 7 feet high, so there is not a lot of clearance between the mains and the floorboards and joists.  He may be able to make an antler off of the main to accommodate a Gorton 2.  He currently has either 3/4 or 1" reduced by couplers to the 1/8" for the Varivalve.  I haven't seen that before.

    Bryce is getting water spewing out from his kitchen's fin rad's heattimer.  He is filling his boiler from a really strange spot - it's as if he is filling his return and then the water spews over the Hartford loop into his boiler.  I am giving him the autofill from my boiler to see if he can save a buck or two.  I don't know if he is getting wet steam or if he just has too much water in the system.  I would guess that his piping is not correct, but at least he does not have a bullheaded t. 

    Rod, I was surprised that you think that the Heattimers were really only for problem rads - I have been using them with good success on my system.  Oh well, each one of these systems is different, for sure.

    Bryce is in good hands with my pro.  No worries!
  • RodRod Posts: 2,067
    edited November 2011
    Auto Fill Compatibility

    Hi Patrick- I’m glad you were able to give Bryce a hand and set him up with a good pro. From personal experience I can really relate to the situation of moving into a new home and having to deal  with a steam system you know nothing about nor it seems, does anyone else.

    Just a couple of thoughts:

     On the Auto Fill- Make sure the LWCO probe and the autofill are compatible. Some aren’t!

    Heat Timer vents- While the Heat Timers have their place, people seem to use them as a “fix all” to try to make up for inadequate venting by venting their mains through their radiators.  How well they work out seems to depend on the individual system and the boiler size of the system.  I’ve noticed they seem to be a less of a problem if the boiler is oversized . It’s when the boiler is equal to or slightly undersized problems can arise.

           As I mentioned in a earlier reply in this post, it isn’t just faster venting you must consider. It is the rapid condensing and huge vacuum condition that the rapid venting can cause.  The larger downstairs radiators, closer to the boiler, “hog” all the steam and the small radiator in the bathroom upstairs doesn’t get any. After a while as they warm up, the condensing in the “Hog” radiators slows down so the small radiator now starts getting steam but never gets a chance to get hot as the burner shuts off due to the fact that the  room with the “hog” radiators is now warm and also contains the thermostat. Slower vents on the radiators allows the sharing of the available steam among all the radiators which gives you a balanced steam system.  

       Another problem which can also be annoying is what Bryce is experiencing in his kitchen, the lack of a float in the Heat timers. As I say the Heat Timer have their place it’s just that generally I think you get a better balanced system and therefore more comfortable heating using slower radiator vents.

    - Rod
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