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  1. #1
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    pressure testing systems



    I have a fellow tech who pressur tests systems with a hermetic compressor basically suction open to atmosphere delivery connected to system ,me it's own or nothing any thoughts on this?



  2. #2
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    Re: pressure testing systems

    Pressure wise its a test but he is filing the system with moisture. poe oil is will absorb it and vacuum will not take it out. Not smart thing to do.

    OFN is whats he needs.

  3. #3
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    Re: pressure testing systems

    He would possibly generate service work for the future to clean up mess he has created.
    If not to late he needs retraining.
    Even in large Industrial ammonia systems we use OFN for pressure testing.

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    Re: pressure testing systems

    If the system is new and with no oil, I don't see any risk for the system in using air as a pressure test fluid, provided that it is folowed by a good vacuum.
    In a system not new the correct way is efectively to use oxygen free nitrogen.

  5. #5
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    Re: pressure testing systems

    Hi all ,

    Quote Originally Posted by cduque View Post
    If the system is new and with no oil, I don't see any risk for the system in using air as a pressure test fluid, provided that it is folowed by a good vacuum.
    In a system not new the correct way is efectively to use oxygen free nitrogen.
    I can agree with above ... all depend what is available on site for pressure test ... on huge plants we usually use instrumental air or huge air driers connected to air compressor/s ... the best is OFN ... but we all know life is not always simple

    Using hermetic compressor with an inline air drier in small systems can be acceptable ...


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    Re: pressure testing systems

    Obviously not performing strength tests though.

    Basic bad practice, would cancel manufacturers warranty.
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    Re: pressure testing systems

    Compressing air for leak testing is going to introduce moisture to the circuit, and that will make the evac more difficult. You basic drier arrangement not going to do much good unless you can afford to re-expand to shift pressurized dewpoint. So: for checking out the install of 1-little evap on an ammonia circuit: Sure, go for it. For just about anything more complicated or involving a refrigerant-lubricant combination thats sensitie to moisture: You could build something; its not just a recouped hermetic....

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    Re: pressure testing systems

    If he has access to OFN then no real excuse for not using it.
    We don't know what type of systems we are referring too.

    Possible problems could be oxidized oil entering system
    Introducing different oil & contaminants into system
    How is hermetic compressor controlled to prevent over pressure
    How is oil level in hermetic compressor monitored?

    We can't all be perfect, but at least try to do right thing.
    We would want to keep it as pure as possible by not introducing anything unnecessary.

  9. #9
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    Re: pressure testing systems

    The type of equipment is catering equipment bottle coolers ,walk in cold rooms and yes I have told him the pitfalls he has a cut out fitted for over pressure and he does have access to ofn but says it's too expensive!

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