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Steam Vents splitting/cracking, why?

jacksonpollack Member Posts: 12
edited November 2022 in Strictly Steam
I have now had seven of these steam vents develop cracks from top to bottom just like in the photo. The cast base has "Taiwan" molded into the casting

These are installed on a one-pipe system on Danfoss thermostatic valves. I love the Danfoss valves, they do a great job balancing the large building.

I have never seen any other vents fail like these. The smaller radiators in the building that don't have the thermostatic valves have a motley collection of Maid o Mist and Hoffman vents that are probably 40+ years old, still work great, and have never split like this.

Are these just very cheap vents and I should be happy they lasted a few years or is there something else going on?

They were installed about a decade ago.


    JUGHNE Member Posts: 11,060
    What pressure does the system run at?

    And yes, they are cheaply made.
  • mattmia2
    mattmia2 Member Posts: 9,629
    Maybe a production issue with when lead free solder became a thing?
  • jacksonpollack
    jacksonpollack Member Posts: 12
    The two pressuretrols are set in the not exactly precise range between 0.5 to 2 psi range.

    I am fairly confident that the system rarely, if ever shuts off from pressure, only temperature at the thermostat. The boiler size is on the small size compared to the load, which has worked fine with the Danfoss valves shifting the heat to the cooler parts of the building.

    I was assuming, perhaps incorrectly that those vents must be able to take 10 psi, which I don't think the system has come close to seeing.

    I was curious if this was a type of failure others had seen.
  • pecmsg
    pecmsg Member Posts: 4,842
    What does the operating gauge say?
  • neilc
    neilc Member Posts: 2,703
    yeah, post pictures at the boiler,
    floor to ceiling, one shot,
    then a closeup on the Ptrols and pigtails, and gage(s), sightglass,
    have you serviced the pigtails?
    known to beat dead horses
  • mattmia2
    mattmia2 Member Posts: 9,629
    Where are these located? Is it possible this is physical damage from furniture or something hitting them or from an occupant unhappy with the temp?
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,202
    edited November 2022
    JUGHNE said:

    "The cast base has "Taiwan" molded into the casting"...

    "Are these just very cheap vents and I should be happy they lasted a few years..."

    The answer is yes. They are garbage and you are lucky they worked at all. They have no business on your system.

    No secret here; they would stress and crack sitting on a shelf.
  • BobC
    BobC Member Posts: 5,477
    Those vents sometimes with USAV imprinted on them are very poorly made. I tried one I got at a big box store and soon reralized it was a mistake. For just a couple of bucks more you can get Maid O Mist which is probably the least expensive decently made air vent, Gortons are the same design (copied from jacobus which was Maid O Mists old name) built a bit better but you pay more. Hoffman and VentRite are very well made but cost more.

    In short you can buy inexpensive vents that are well enough made but the cheapo ones are not worth the price you pay for them.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • ethicalpaul
    ethicalpaul Member Posts: 5,701
    BobC has it exactly right in my opinion. I like MoM but Gorton is great (just a lot more $$). Never buy from a big box store. They used to stock MoM and the other makers but now they are all garbage ripoffs.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el