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Tunstall Radiator traps?

Unhippy
Unhippy Member Posts: 17
in Strictly Steam
I'm slowly getting the imported parts i need to build my mini-tube system and have found Tunstall DBC radiator traps online from a supplier that seems happy to ship overseas (annoyingly very few US based suppliers will these days).

Anyone used or know of them ,good bad or otherwise?.....I was going to use Hoffman 17C-2 traps listed on the Supplyhouse website.....but they won't ship outside US

Cheers for any help

Comments

  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,596
    edited August 2015
    They're a fine company. Family-owned with solid products and great service.
    Retired and loving it.
  • RobG
    RobG Member Posts: 1,850
    How about shipping the parts to a friend in the US and having them forward them to you?
  • Unhippy
    Unhippy Member Posts: 17
    DanHolohan said:

    They're a fine company. Family-owned with solid products and great service.

    Thanks, thats all i need to know!!....

  • Unhippy
    Unhippy Member Posts: 17
    edited August 2015
    RobG said:

    How about shipping the parts to a friend in the US and having them forward them to you?




    Slight problem with shipping them to a friend in the US.......and thats the friend in the US bit.


  • JStar
    JStar Member Posts: 2,752
    I'll second the praise for Tunstall. Your search is over.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    If you could get your pressure down to a couple of ounces, and use orafices, you may be able to do without any traps what so ever.--NBC
    vaporvacZman
  • Unhippy
    Unhippy Member Posts: 17
    I'm aiming for 8 OZ/ sq in pressure with a 8"Hg vacuum condensate receiver= 4.5 psi differential.....sorta needs the traps
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    I think the pressure differential will not be that great within the system as that. There will be a great differential between the outside, (atmospheric), and the inside, (vacuum). For your purposes the sub atmospheric pressures exist throughout the system, and the differential between the supply, and return will be small, and a regulating valve, or orifice could limit the amount steam entering each radiator to only the amount which can be condensed.
    Boiler sizing will be critical in this, and a 2-stage gas valve would be useful here to have high fire at startup, dropping to low fire once steam has filled the system.--NBC
  • JStar
    JStar Member Posts: 2,752
    edited August 2015
    Has anybody used orifices on a vacuum system before? I wonder if the suction pressure would still allow steam to enter the returns.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,596
    Years, ago, I had an engineer who worked at Yale come to a seminar. He told me that they had used return-side orifices on their vacuum system, but went back to traps. I remember what he said because it was so visual. "Each orifice leaks a bit of steam through, which may not be a problem in a pressure system, but when you put a vacuum pump behind it, it's like sucking steam through a screen door."

    For what it's worth.
    Retired and loving it.
  • JStar
    JStar Member Posts: 2,752
    I'd say that's worth a good chunk of cash and a day's worth of work. The money's no problem, but there's no way to get that time back. And then to go around again and remove all of the orifices that didn't work.
  • Unhippy
    Unhippy Member Posts: 17
    DanHolohan said:

    but when you put a vacuum pump behind it, it's like sucking steam through a screen door."

    Lol thats kinda the vision i had when the orifices first were mentioned instead of traps.....steam thundering off down the return lines and the receiver vacuum pump spitting steam and water out as it tries to maintain vacuum.

    i know technically the orifices "should" be able to be sized correctly for the pressure to vacuum gradient ......but i suspect that finding that perfect size for each radiator would rather do my head in.....traps might cost a bit more but they work......
  • JStar
    JStar Member Posts: 2,752
    Orifices work great on pressure systems. It's really not that difficult to calculate the proper size. In fact, there is a quite a bit of range for every fractional size opening. It's all based on the EDR of the particular radiator and Delta-P. The only trouble I've had is with some oddball older radiators and custom pipe-radiators that don't have standard ratings. I start small, and enlarge the opening if needed.

    My guess is that the orifice openings in a vacuum system would be very tiny. Maybe too small to be effective in all but the final cut-out suction pressure setting. I don't think I would install them on the return, though. Condensate return is too critical to restrict it's flow and to trust the orifices to remain clean.
  • t.p.tunstall
    t.p.tunstall Member Posts: 18
    Our facility has the capability of shipping worldwide.
    Send your requirements to me @ tp@tunstall-inc.com
    thanks

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