1. #1
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    Question Problems with Scott Regulators

    My department has been using Scott SCBA'a since the beginning of time and we never had any problems with them, until recently. Since putting new units in service last year, we have a problem with the vibalert activating when the packs are full, 1/2 etc(not low air situations). We have had the 1st stage regulators replaced twice and we still have problems. I have been told that the problem stems from temp and moisture. Is anyone else having problems similar to this?

    Thanks

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    I have been told that the problem stems from temp and moisture

    The first time I had a problem with a Scott was this past December. Similiar symptoms.

    Problems were traced back to a moisture filter that wasn't working on our compressor -- solution was to fix the compressor, drain the cascade, drain the airpack bottles. Get dry air back in everything.

    Since it took a bitterly cold & long fire for the problems to occur, I don't know yet if that work has fixed the problem, but until proven else wise, I'll go stay with the water-in-the-bottles being the source of problems!
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    there was something on firefightersclosecalls.com about scott packs you may want to check there to.

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    Default Re: Problems with Scott Regulators

    Originally posted by CaptainS
    My department has been using Scott SCBA'a since the beginning of time and we never had any problems with them, until recently. Since putting new units in service last year, we have a problem with the vibalert activating when the packs are full, 1/2 etc(not low air situations). We have had the 1st stage regulators replaced twice and we still have problems. I have been told that the problem stems from temp and moisture. Is anyone else having problems similar to this?

    Thanks
    http://www.firefighterclosecalls.com/averted.shtml

    I have been told that when scott piston seats get worn it will allow air to leak by and set off their alarm at low temperatures, even with the scott specified grade of air. You could find a walk in freezer to test out whether its temperature related.

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    We have not experienced this problem that you described. It may be that since we are in Texas and the normal low temperatures do not get below freezing we will not experience the same problems. I take it from your original statement that you have contacted Scott directly. Dealing with the vendor may just be a stop gap measure who amy not fully understand the gravity of this situation.

    Since some of the postings have related to a worn pistion, what is the age of the units? How often are they bench tested? Who completes the testing of the units and are they a certified Scott repair facility?

    If the units are not being tested it may be a good idea to have all of the units tested and instected by an authorized testing facility.

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    First, we have to understand that the vibralert is activated by high pressure. I know that sounds strange, but it is correct. Let me walk you through how the vibralert works when it works correctly, then I'll tell you what I think your problem is.

    Normal operation; air comes from the cylinder to the reducer. The air is supplied to the 1st stage, 2nd stage and the transver valve. Because the air is at high pressure, it causes the transfer valve to hold the 2nd stage closed. Air is moving through the 1st stage to the reducer. Air comming through the 1st stage is at 125psi to the regulator.

    As the cylinder is used, the pressure falls. At about 1/4 of the bottle, the pressure on the transfer valve is such that it causes the transfer to actuate, and close the 1st stage valve, and open the 2nd stage valve. The air is moveing through the 2nd stage to the regulator at about 250psi.

    So, the low cylinder pressure causes the regulator to get high pressure.

    Clear as mud?

    Now, the higher (250psi) pressure causes the vibralert to actuate. The vibralert only actuates with the higher pressure (250psi).

    My guess, and I stress guess, is that the 1st stage filter is very dirty, and or clogged.

    I have had 2 come into the shop with the complaint of the vibralert going off early, or all the time. On both of them, somehow, mud had been forced all the way to the filters, blocking the 1st stage. In both of those cases, they had to be completly torn down, new filters, seats, orings, even had to replace the gauge line due to mud in it.

    My advice: Get them tested, and torn down to check the filters.

    Hope this helps. Let us know what you find.
    Check out my blog: The Fixit Shop

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    Originally posted by BFDLT32

    Since some of the postings have related to a worn pistion, what is the age of the units? How often are they bench tested? Who completes the testing of the units and are they a certified Scott repair facility?

    The units have been in service now for a little over a year. Have had the 1st stage regulators replaced twice and have been tested each time afterward. We are not a real busy company, not alot of work for the units

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    I know it's probably not good practice but, you can leave the purge open so the alarm won't go off. Better than having a dead battery on the pas. When we first got the new packs that was a common problem, but is seemed to lessen with useage of the pack
    Last edited by chick813; 03-25-2005 at 02:44 PM.

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