Results 1 to 14 of 14
  1. #1
    Join Date
    Jun 2010
    Location
    Denmark
    Posts
    11
    Rep Power
    0

    Oilchange, how to ?



    Hi, I need to change oil on a Bitzer provision compressor. Model 4G-20.2Y-40P

    Can anyone in here please check if this is the right way to do it. If not please correct me..

    Thanks.........

    1. Close suction valve and wait untill compressor stops.

    2. Turn off compressor

    3. Close outlet valve from compressor.

    4. Open valve marked C on attached picture.

    5. Drain old oil through C

    6. Fill oil through C with a handpump.

    7. Cloce valve C

    8. Connect vacuum pump to compressor outlet valve.

    9. Turn on pump and pump out moisture in compressor.

    10. After this open suction valve and start compressor.

    Can it be done like this ?

    What is A and B on the picture ?
    Attached Images Attached Images



  2. #2
    Join Date
    Oct 2007
    Location
    manchester
    Age
    43
    Posts
    5,709
    Rep Power
    39

    Re: Oilchange, how to ?

    b is normally crankcase pressure
    a is oil pressure outlet port- normally 15psi above crankcase pressure
    if ur pumping down the comp, then you will still have gas in ur heads, if this is the case then u have to vac on the suction side only, then you can vac the oil in on C with a 1/4 line into your new oil
    saves pumping it in.
    dont forget to energise crankcase heaters for 24 hrs - whilst vaccing prior to starting

  3. #3
    Join Date
    Jun 2010
    Location
    Denmark
    Posts
    11
    Rep Power
    0

    Re: Oilchange, how to ?

    Sorry, I am not working on compressors very often, so i am a little confused.

    Could you please make a step by step how to do list.

    I am not going to do this oilchange alone, but my boss (i am a apprentice) wants me to make a how to do list before we starts the job.

    He knows how to change the oil, but he wants me to find out myself.

    So if you also could explain how to do it I would be very happy.

    Thanks....

  4. #4
    Join Date
    Oct 2007
    Location
    manchester
    Age
    43
    Posts
    5,709
    Rep Power
    39

    Re: Oilchange, how to ?

    1. Close suction valve and wait untill compressor stops.

    2. Turn off compressor

    3. Close outlet valve from compressor.

    4. Open valve marked C on attached picture.

    5. Drain old oil through C

    6. Fill oil through C with a handpump.
    connect vac pump to low pressure side of the compressor, connect a gaugeline or 1/4 pipe with a flare nut on port C- run your vac pump and this will create a vacuum on the compressor body which will suck the oil into the compressor-saves on pumping

    7. Cloce valve C

    8. Connect vacuum pump to compressor outlet valve.

    connect to the low pressure side only
    9. Turn on pump and pump out moisture in compressor.
    if you remove the fuses/shut the breaker off for the compressor and power up the unit- the crankcase heater will warm the compressor sump

    10. After this open suction valve and start compressor.

    Can it be done like this ?

    What is A and B on the picture ?

  5. #5
    Join Date
    Feb 2007
    Location
    UK
    Posts
    2,479
    Rep Power
    38

    Re: Oilchange, how to ?

    Challenger,
    Just adding to / editing your list;
    0.1 Check for leaks.
    0.5 Connect gauges.
    1 Shut liquid line valve or solenoid and wait for the system to pump itself down.
    1.5 Ensure crankcase/suction pressure is 0 or below
    3 Close compressor's suction and discharge valves.
    3.5 Release the refrigerant trapped in the compressor's discharge side in to suction line.
    5. Drain old oil through C, using OFN to push it if necessary.
    6. Connect vacc pump to compressor at as many points as reasonable possible, ensuring both high and low sides are covered.
    7. Start vacc pump.
    8. Suck oil in through "C"
    9. When the oil is at the correct level shut valve "C" and continue vacuuming until desired level of vacuum is achieved.
    10. Open suction, discharge and liquid line valves.
    11. Reinstate the system.
    12. Check for leaks.
    13. Clean up.

  6. #6
    Join Date
    Aug 2006
    Location
    england
    Age
    43
    Posts
    3,781
    Rep Power
    38

    Re: Oilchange, how to ?

    Make a note of the oil level on the sightglass before you drain it then you can fill it back to the same level.

    Re check oil level once it has been running, seem to remember some compressors have one way valve in sump to allow oil to drain from the motor side to the sump but prevent oil going in the other direction.

    Or you could measure what comes out and put the same back in, still check level though after some run time.
    Mostly found in Oxfordshire, UK :)

  7. #7
    Join Date
    Aug 2007
    Location
    Adelaide Australia
    Age
    63
    Posts
    536
    Rep Power
    17

    Re: Oilchange, how to ?

    Hi Challenger
    You might also want to add in the following before you drain the oil,
    1A. Shut the oil return (if this compressor has one)
    2A. Turn off crankcase heater and tag.
    2B. Isolate compressor and tag out / lock out
    Regards
    Paul

  8. #8
    Join Date
    Jul 2010
    Location
    NTH.QLD Australia
    Age
    55
    Posts
    1,754
    Rep Power
    26

    Re: Oilchange, how to ?

    This might get a little messy, so fit a line onto "C" valve outlet before draining oil.
    Make sure your container capacity is way bigger than the amount of oil you are removing.

    Some compressors here only have 1/4 or 1/8th BSP bungs. Lesson learnt when there is 10 PSI pressure remaining in the crank case.



    To the optimist, the glass is half full. To the pessimist, the glass is half empty.

  9. #9
    Join Date
    Jun 2010
    Location
    Denmark
    Posts
    11
    Rep Power
    0

    Re: Oilchange, how to ?

    Thank you...... You are all the best !!!!!!

  10. #10
    Join Date
    Jun 2010
    Location
    Denmark
    Posts
    11
    Rep Power
    0

    Re: Oilchange, how to ?

    1.jpg2.jpg

    Hi again
    A few more questions.

    On the suction valve on the compressor there is no fitting I can connect vacuum pump to. It has a blind fitting only. How can I remove this blind and connect another fitting ?
    My guess is that this blind (marked H on picture) would be in open position if the suction valve is closed.
    And H would be closed if suction valve is open.
    If this is correct then would it be possible to remove the H plug when suction valve is open, and mound another fitting instead of the blind.

    On discharge valve this "I" fitting is open when the discharge valve is closed.
    I know this because I tryed to unscrew the cap on "I" fitting while the discharge valve was open, and I could hear/feel gas coming out from "I".

    Are these suction/discharge valves working as 3-way valves with these "H" and "I" fittings ?

    Thanks again......

  11. #11
    Join Date
    Jun 2010
    Location
    Denmark
    Posts
    11
    Rep Power
    0

    Re: Oilchange, how to ?

    Sorry the work open should be changed to Closed. Like this.....


    On discharge valve this "I" fitting is open when the discharge valve is closed.
    I know this because I tryed to unscrew the cap on "I" fitting while the discharge valve was CLOSED, and I could hear/feel gas coming out from "I".

  12. #12
    Join Date
    Feb 2007
    Location
    UK
    Posts
    2,479
    Rep Power
    38

    Re: Oilchange, how to ?

    Yes to pretty much all you said in the last 2 posts.



    .

  13. #13
    Join Date
    Jun 2010
    Location
    Denmark
    Posts
    11
    Rep Power
    0

    Re: Oilchange, how to ?

    Ok I just wanted to be sure it is safe to open up this blind plug while suction valve is open and compressor is running.

    Thanks....

  14. #14
    Join Date
    Jul 2010
    Location
    NTH.QLD Australia
    Age
    55
    Posts
    1,754
    Rep Power
    26

    Re: Oilchange, how to ?

    Quote Originally Posted by Challenger View Post
    Ok I just wanted to be sure it is safe to open up this blind plug while suction valve is open and compressor is running.

    Thanks....
    Back seat your valves then remove the plug and install fitting for gauge line.
    To the optimist, the glass is half full. To the pessimist, the glass is half empty.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •