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  1. #1
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    Ammonia CA Store Complex



    Hi Everyone

    I have a client who has just added 8 CA Stores to an existing 12 CA stores.

    Ammonia was added to the plant to accomodate the new CA store.

    There are currently Danfoss ICS solenoid valves with NC Danfoss EVM's.

    the EVMS on the pump liquid and the suction solenoid valves are continuosly jamming causing the solenoid valve to remain open. When the EVM is opened there is a waxy substance that is causing the plunger to remain in an open position. This substance dissolves in your hand.

    This problem was localised to the 8 new rooms but has since affected affected the remaining rooms that are all operating with the ICS solenoid valves. The older rooms which have Danfoss PM valves are not affected even though they are all using Danfoss NC EVM's.

    I have run a test on one room by switching out the Danfoss EVM with a Hansen MS Module to eradicate the posibility of the Danfoss products being at fault.

    I suspect there has been some contamination in the system, there have been very fine strainers added at various points to filter out any unwanted materials but these are always clean.

    I have tested the ammonia for any water content and sent all compressor oil samples for testing, all of these came back with no indication of moisture in the refrigeration plant.

    I have attached a picture of the substance. Any help on this matter would be greatly appreciated.
    Attached Images Attached Images



  2. #2
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    Sep 2007
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    Re: Ammonia CA Store Complex

    Hi.
    What Oil was being used and what Oil is now being used?
    Sounds like Waxing to me!

    Alternatively were suction socks or strainers used in the newly installed pipework?
    Just some thoughts
    Grizzly
    Despite the High Cost of Living it still remains Popular!

  3. #3
    Join Date
    Nov 2009
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    france
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    Re: Ammonia CA Store Complex

    It could be the oïl or grease used to protect the new pipes during storage. waxed by the ammonia and staying in your EVM




    Quote Originally Posted by Grizzly View Post
    Hi.
    What Oil was being used and what Oil is now being used?
    Sounds like Waxing to me!

    Alternatively were suction socks or strainers used in the newly installed pipework?
    Just some thoughts
    Grizzly

  4. #4
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    australia
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    Re: Ammonia CA Store Complex

    A.King,
    As stated above as well as with extension, was the equipment & pipe new, or secondhand from somewhere else?
    Can you also explain how you tested for water to avoid overlooking something basic.
    Alo when pressure testing pipework, what was used, air, nitrogen?

  5. #5
    Join Date
    Sep 2009
    Location
    Iran
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    Re: Ammonia CA Store Complex

    hi
    as you know we have dead point some time in our piping
    when you add new system mostly it effict to our dead point and moved all waxes and oils and also dirty pieces

  6. #6
    Join Date
    Nov 2017
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    South Africa
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    Re: Ammonia CA Store Complex

    Hi Gents

    Thanks for the replies.

    The oil that has been in use is an ISO68, this has not changed and is still in use. There are also mulitiple Strainers/ socks in the Liquid and suction lines.

    The pipework and equipment was all new. Nitrogen was used for the pressure test.
    To test for water we installed a de- watering unit and left this running for roughly two weeks. I also drained some -10 liquid ammonia into a glass beaker and let the ammonia boil off, once this had boiled off there was no water remaining.

    What puzzles me is that this is a common system and the EVM on the old Danfoss PM valves are not affected, the only difference between the PM and ICS valve is that the EVM is in a horizontal position instead of a vertical position.

    If it is waxing from the pipework is there an efficient way to remove it.

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