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New here with new compressor

Discussion in 'Compressors, Boosters and Blending Systems' started by peterdulux, Jul 10, 2015.

  1. peterdulux

    peterdulux Garibaldi

    Hello every one, I' am new here and have some questions that I'll need answered at a very basic level. So hopefully you'll all be patient with me please.

    I have purchased a used coltri compressor that is older but functioning. Seller said it was a couple years old when he bought it in 2006 serial number 400795.

    The purpose for the compressor is for filling carbon fiber scuba tanks to be used for filling pcp air rifles (not paintball, but same concept). So air purity, in the breathing sense, is not required.

    We take the scuba tank out when we shoot and refill our guns when the pressures drop to around 110 bar.

    Are there any manuals available online? Anyone care to guess what model it might be?

    Wondering, what size I.D. can or should the fill line be? We use micro bore, with an id of 1.78 mm, to reduce lost or wasted air. Should the id of the fill line be based on the cfm of the compressor? Which I don't know at this moment.
  2. WarrenZ

    WarrenZ Solo Diver

    # of Dives: 200 - 499
    Location: Las Cruces NM
    Scuba fill whip is usually 1/4" or larger.
  3. swamp diver

    swamp diver Barracuda

  4. ti325v

    ti325v Dive Shop

    # of Dives:
    Location: Con Dao Islands Vietnam. Owner of Dive ! Dive ! Di
    I have all the manuals...
    Photos of the unit will help, along with motor size, but it may have been changed if the compressor has been down rated.
    or contact Ray Contraras at Compressor stuff.
    USA distributor...nice guy has all parts..He can look it up in the books based on serial number...
    Easy machine to work on. I have two.....and a really nice Bauer.

    Regarding the hoses...All of the S.S. tubing on the compressor is 1/4 inch O.D. (250 thousands) with about a .150 inner diameter...and about a .045 wall thickness.
    Whip hoses should have a similar I.D., I believe this size tubing is good to at least 15 CFM at 300 BAR.
    There is no saving of air with small tubing.
  5. rcontrera

    rcontrera Dive Equipment Manufacturer

    What you have is a 20 year old MCH6 compressor. Depending on the driver, capacity can be from 2.8 CFM to 3.6 CFM. The standard size of fill line is 1/4". there is no reason to change fill hose size other than length. I regularly use the standard 1/4" as well as 3/16" for runs that have lots of bends and twists.

    You can download a manual as well as a diagram and parts list at:
    Coltri Sub High Pressure Breathing Air Compressors manuals from Ray Contreras Sales

    The best things you can do to insure you get clean air and pump for a long time is to keep it clean, drain the condensate more often than you think you need to, change the oil and filters regularly and NEVER pump bulk tanks.

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