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Maid-O-Mist Failure Rate ?

Harry_6
Harry_6 Member Posts: 141
Is it just me, or perhaps a bad batch, but I have recently been finding that after about a year the failure rate of Maid-O-Mist radiator vents has been around 15%. I installed 15-20 in a house and a year later 3 have failed shut. Has anyone else had this experience?

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,725
    edited November 2022
    Water or Steam?
    Never mind, I just saw you posted in Strictly Steam!
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • BobC
    BobC Member Posts: 5,476
    Is the boiler water reasonably clean?

    Many years ago i had a few (2 out of 6) with the wrong thread on them - straight threads, not tapered. I ran those through my 1/8 NPT die and installed them. That has to be 8-9 years back and they have all worked fine since.

    i did contact Maid O Mist and they went through the stock on hand and said all the threads were fine. They did offer to replace them but I had already reworked them. You may have gotten a bad batch, i would contact them and see what they say.

    Bob
    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
  • ChrisJ
    ChrisJ Member Posts: 15,592
    BobC said:
    Is the boiler water reasonably clean? Many years ago i had a few (2 out of 6) with the wrong thread on them - straight threads, not tapered. I ran those through my 1/8 NPT die and installed them. That has to be 8-9 years back and they have all worked fine since. i did contact Maid O Mist and they went through the stock on hand and said all the threads were fine. They did offer to replace them but I had already reworked them. You may have gotten a bad batch, i would contact them and see what they say. Bob


    They went through all of their stock and all the threads were fine.


    Sure they did...... 

    I'm selling a bridge if you're interested.
    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
  • BobC
    BobC Member Posts: 5,476
    edited November 2022
    I worked as a tech and then an engineer at a military quality power supply house for 25 years. The reason military hardware costs so much is the mind numbing number of tests something has to be subject to to pass a military quality test. We had to follow the DOD quality practices and went through an audit every year to make sure those standards were meant. Part of the requirements were to use the AQL method to make sure a given part was up to snuff. A number of units would be randomly selected and subjected to a battery of tests. A table in the MIL spec was used to determine how many of a batch were subject to the tests.

    When I contacted MOM I told them the date, vendor and failure rate I encountered. I talked to someone down there a couple of days later and they said existing units from that batch had been looked at and records examined, they could find no evidence of bad units. This was not something that took detailed examination, you could tell something was off so I was willing to believe it was a random event. The gent I spoke to gave me his extension number and asked me to call him if I found any more bad threads.

    I worked in QA long enough to smell a rat and this didn't smell like one to me.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    ChrisJCLambethicalpaul
  • ChrisJ
    ChrisJ Member Posts: 15,592
    BobC said:
    I worked as a tech and then an engineer at a military quality power supply hose for 25 years. The reason military hardware costs so much is the mind numbing number of tests something has to be subject to to pass a military quality test. We had to follow the DOD quality practices and went through an audit every year to make sure those standards were meant. Part of the requirements were to use the AQL method to make sure a given part was up to snuff. A number of units would be randomly selected and subjected to a battery of tests. A table in the MIL spec was used to determine how many of a batch were subject to the tests. When I contacted MOM I told them the date, vendor and failure rate I encountered. I talked to someone down there a couple of days later and they said existing units from that batch had been looked at and records examined, they could find no evidence of bad units. This was not something that took detailed examination, you could tell something was off so I was willing to believe it was a random event. The gent I spoke to gave me his extension number and asked me to call him if I found any more bad threads. I worked in QA long enough to smell a rat and this didn't smell like one to me. Bob

    I'm curious why a military generator using a 4A032 is so massive and heavy but only 3kw.

    We have several of these engines at work and they just seem..... anemic.

    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
  • BobC
    BobC Member Posts: 5,476
    Military gear is very conservatively rated but should be very robust. This assumes all the specs were met and it wasn't affected my chicanery in the procurement process. Commercial gear is usually lightly built and only lasts a few years, When I was overseas (many decades ago) we had generators 20+ years old that were used 24/7 and they just ran and ran as long as the PM was done.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Harry_6
    Harry_6 Member Posts: 141
    Boiler water is fairly clean. Years ago I had a Gorton vent, out of the box, perfect and beautifully plated except with no vent hole machined in it. It was as good a vent as a pipe plug is.
    EdTheHeaterMan
  • PaulKolb
    PaulKolb Member Posts: 4
    Check for rust inside vent . My MoM vents internal bimetal strips rusted after one year and the vents stopped working.
    Shake/tap the vents to see if any rust particles come out.
  • RTW
    RTW Member Posts: 42
    As an aside, once a vent is installed and confirmed working, is there any consensus as to how often one should boil/clean them in white vinegar? Its been suggested to boil them approximately 5 minutes on this site but never read anything about frequency. Regards, Bob
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    I don't touch mine until/unless they show a failure
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    CLamb
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    To what extent does boiling have any positive effect? Agitation, increased rate of chemical reaction, magic?
  • Neild5
    Neild5 Member Posts: 167
    Our building has approximately 100 radiators, I switched over to MoM as the old ones failed, in the last 5 years I had 2 of the new ones fail to the point that a vinegar bath didn't work. 
  • dko
    dko Member Posts: 576
    edited January 4
    How many years would you say a specific vent should last to get your money's worth?
  • BobC
    BobC Member Posts: 5,476
    edited January 5
    A MOM #5 costs 36% as much as a Gorton #5 on Supplyhouse.com - that tells me a Gorton would have to last almost 3x as lonh assuming your replacing them yourself.
    I've used them for about 8-10 years now and had no failures. I replaced all my Hoffman 1a's with MOM because the Hoffmans did not work on my system. I think ChrisJ was having the same problem, both our systems hace long horizontal radiator runouts.
    The Gorton's seem better built but are they 3x better? i settled on them because of the interchangeable orifice. I have noted some complaints about them here but don't know how widespread it might be.

    Bob
    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