Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Blowdown With King Valves?

@DanHolohan says 10psi blowdowns will extend the life of boilers and @New England SteamWorks does them.  Yet king valves are rarely installed.  Any idea why?  

Does anyone have a video of a 10psi blowdown of a residential boiler?




  • Jamie Hall
    Jamie Hall Member Posts: 23,272
    Why? King valves aren't cheap. They have to be full port ball type valves. Priced them out lately?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • cross_skier
    cross_skier Member Posts: 201
    Maybe $60 to $100 for valves.  Seems cheap if they are effective at flushing the muck out of a boiler and extending the life a boiler a few years

    @DanHolohan says gate valves or butterfly valves are appropriate for king valves.  I watched @ethicalpaul 's video and he chose ball valves for his risers.  Would ball valves be ok?

  • delcrossv
    delcrossv Member Posts: 742
    edited January 2022

    Why? King valves aren't cheap. They have to be full port ball type valves. Priced them out lately?

    Or rising stem gates in the larger sizes. $$$$

    Full port, steam rated ball valves are fine. Don't forget you need to isolate the return as well.
    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • cross_skier
    cross_skier Member Posts: 201
    I brought a pair of 2" Nibco T-111 rising stem valves for a $50/shipped.  That's not a lot.  I think they will be suitable.  They were new old stock.

    Yes, I'll be using a 1-1/2" ball valve to isolate the return.
  • ethicalpaul
    ethicalpaul Member Posts: 5,701
    My ball valves are getting stiff. This may be a a downfall of all valves...exercise them every season.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • retiredguy
    retiredguy Member Posts: 901
    edited January 2022
    Every steam job should have Dan's set up to remove the mud in the mud leg. A gate valve on the discharge (king valve) and a or butterfly or ball valve for the blow down is not that expensive when compared to the cost of a premature boiler failure. I always preferred USA valves to the foreign junk since the USA valves always lasted much longer.
  • Motorapido
    Motorapido Member Posts: 307

    My ball valves are getting stiff.

    You better go see the doctor for that symptom.

    JUGHNE Member Posts: 11,058
    Yes, exercise your valves at least every year, that includes you Paul.

    Most of the King valves I have seen are from the 30's & 50's.
    Almost always 10-12' off the floor.
    3-5" flanged gates that have not been touched since installation by dead men.
    A couple have leaking flanges.
    Might just remove them and insert the short piece with flanges instead.

    There is a term for that double flanged nipple, can anyone tell me?

    I figure I will not even try...might get them closed and not reopened.

    Have some 2" ball valves for Kings above steam boilers that are only 20 years old.
    Got 1 out of 4 to move.
  • cross_skier
    cross_skier Member Posts: 201
    Thanks, any experience with Nibco T-111's? They are rising stem gate, probably American made.
    EBEBRATT-Ed Member Posts: 15,512

    The Nibcos are rated 125 psi steam. Cheap valve but ok.

    @Jamie Hall Nipple with 2 flanges =spool piece

    Not all ball valves are steam rated.

    I always like Apollos...probably more $$$$$ than most

    They even make Carbon Steel ball valves like the Apollo 89-100 with options for 250 # steam

    I would be almost certain those Nibco's are made in China not that it matters
  • delcrossv
    delcrossv Member Posts: 742
    Just do the blowdown annually and they'll be fine.
    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • cross_skier
    cross_skier Member Posts: 201
    Just to be sure I picked up two Apollo 2" forged carbon steel ball valves for a nice price.  Those are critical valves.  I'll dump the Nibcos on eBay

  • ChrisJ
    ChrisJ Member Posts: 15,658
    I open and close my king valves yearly but have never used them.
    I wash everything out with a wand.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • KC_Jones
    KC_Jones Member Posts: 5,736
    I have done 2 blowdowns on mine since 2014, with my water treatment it just doesn't get that dirty. The blowdown is....entertaining. It does blast the water out for sure.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15