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Provion for future flush of wet return on steam system

Don't I also need a valve and drain on the "upstream" side to "fill" and flush the return?


  • Jim Murphy
    Jim Murphy Member Posts: 15
    Provision for future flush of wet return on steam system

    Hi all,

    I'm planning to have my wet return replaced on our steam heat system and want to make provisions to easily flush it in the future. I know that I need to add a couple of valves and draincocks in order to do so, but I want to make sure that I have the appropriate lingo down for when I talk to my heating contractor.

    Can somebody educate me as to exactly what to ask for?

    Thanks in advance,
  • Big Ed
    Big Ed Member Posts: 1,117
    On the Hartford Loop

    Install a drain valve on the wet return before it rises up and into the equalizer .Also Install a ball valve on that riser,between the equalizer and that return's drain valve.....
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    I would ask

    for the wet return low ends to be full-size tees or at least have tees before the elbows. Into these tees would screw FULL PORT ball valves with hose-end connections.

    For flushing, the "end" or normal "run" of the tee would be where I would put the valves with the branches being the flow paths.

    You may well want to give them a diagram just to be sure. That can clear up a lot of misunderstandings.

    Also, you are using Schedule 80 steel rather than Sch. 40, right?

  • Big Ed_3
    Big Ed_3 Member Posts: 170
    Better Setup

    I like Brad's set up using a ball valve over the drain valve. Thanks
  • Big Ed_3
    Big Ed_3 Member Posts: 170
    Three Ways

    By shutting off the ball valve on the return riser and opening up the drain valve you can ..... 1- Build up steam pressure to force out condensate and steam clean return. 2-Over fill system to let the returning flowing water rinse the return. 3-Attach a garden hose to the drain valve to back flush the return if need be. I like Brad's set up because you can also send in a rod to help loosen mud... Tools ..Give your self the tools ,gives you the means.......
  • Jim Murphy
    Jim Murphy Member Posts: 15
    I get it now

    Thanks very much guys.
  • Jim Murphy
    Jim Murphy Member Posts: 15
    Just saw something...


    You mentioned using Sch 80 rather than 40. Actually I was thinking to have it done in copper, for less corrosion. I know that copper is bad for near-boiler piping and mains, but thought it was OK for returns as long as you also use dielectric unions. Am I asking for trouble?

    Please give me more "tools" ...
  • Tim Gardner
    Tim Gardner Member Posts: 183

    I've never seen a full-port ball valve with a hose-end connection. Do you mean screwing a hose adapter onto a threaded ball valve, or does someone actually make/sell them?

    Also, are there any safety issues with drain valves? Someone could release a lot of hot condensate pretty quickly with a ball valve. Is there a good way to do it that is both convenient and safe?
  • Jim

    Try and stay with black iron when at all possible. Here is a drawing of the valve and drain configuration and better yet with a dropped header.

    Glenn Stanton

    Manager of Training

    Burnham Hydronics

    U.S. Boiler Co., Inc.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    NPT Connection

    Yes, a hose adapter is used most commonly. There may be a company like Apollo who makes hose-ready ball valves, but then you could not use it for anything else.

    If you have concerns you can get locking hasps for the ball valve handle or use one with a spring-return which will fail the valve closed. I use the latter when draining the base of a stack for example.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Jim- Do what Glenn says

    Yes, stay away from copper, use steel and the heavier the better. Copper? You made of money or what? :)

    In the diagram above which Glenn posted, the angle drain cock would be where the full-port ball valve would go. (Could use a little room of course, in real life, but you know that :) )

  • Tim Gardner
    Tim Gardner Member Posts: 183

    Thanks for answering; that makes sense.

    For clarification, what size ball valve? For example, my return is 1 1/2.

    Are you suggesting using a 1 1/2 ball valve followed with a bushing down to a hose adapter?

    Or are you suggesting going from 1 1/2 to 3/4 with a bushing and then using a 3/4 ball valve followed by a hose adapter?

    Or something else?
  • Tim , here's a pic of Clammy's latest

    I hope he doesn't mind . He used a full port ball valve for the boiler drain and used a bushing to adapt it to a hose connection .

    To be safe , keep a hose cap over every drain valve .
  • Matter of opinion

    Like you thought , copper on the returns does not scale up or corrode like steel does . But ..... it takes long decades for steel to scale up or corrode . Some steam systems we replace have no scale at all in the steel returns , some over 60 years old .

    I've been using copper on returns for over 20 years with no problems to speak of . Although I do agree a reaction can occur between the dissimilar metals , I have yet to see this reaction on systems we replace with existing copper returns . I would like to know if any steam boiler manufacturers can point us to info about this subject , or if they did testing with copper ?

    But with the astronomical cost of copper , I would go with the steel . It's thicker , stronger and just looks a sight better .

    Here's a pic of how we pipe the return with a flush valve .
  • Tim Gardner
    Tim Gardner Member Posts: 183

    I see. This would make it really easy to clean it. Thanks for the picture.
This discussion has been closed.