No announcement yet.

fitting question on a air compressor

  • Filter
  • Time
  • Show
Clear All
new posts

  • fitting question on a air compressor

    Still waiting for my electrian to hook up my outlet for my air compressor. meantime, still trying to figure out my air compressor fittings.
    I purchased a vt6271 horitizontal air compressor from C-H. Trying to figure out what the size of fitting that needs to go into my regulator on my air compressor (it came with a regulator) so I can connect a hose to it. I looked in the manual and it doesn't say anything about the size of the hole on the regulator for a fitting to fit. Are they all a standard size? Is there a way to find out or call the company?

    Another question. I want to use a 1/2in air hose for my 3/4 impact wrench. However, my impact wrench has a 3/8 npt fitting. To my understanding, the npt represents the female end on the impact wrench? I can't use a 1/2in fitting, it has to be a 3/8 male end to fit into the impact wrench? So I should by a 1/2 in hose with 3/8 npt ends? Sorry for my stupidness. I'm trying to learn this info.

    Thanks for any advice.


  • #2
    Re: fitting question on a air compressor

    Cannot say what size the fittings are as regulators come in 3/8, 1/2 and 3/4 npt sizes, with 3/8 being the most common. Measure it and make a trip to the nearest hardware store and measure their pipe nipples. With that size compressor, the regulator is probably 1/2 or 3/4 npt, but I would guess 3/4 based on the specs (it says 3/4" output port).

    As for the impact gun, running a 1/2 air hose to the gun is counterproductive as it will be unwieldy. If it is necked down to a 3/8 NPT thread, than a 1/4" id (inside diameter) air fitting is what will fit (they do make high volume (5/16 id) fittings that will screw into 3/8 npt threads, but are expensive. They are made for the HVLP spray guns and you will need both male and female quick disconnects if you change to them to get more air volume. That said, dropping down to a 3/8 hose (1/4 id fittings) for the last 5 - 10' from the wrench will not appreciably diminish the volume of air you get, and air pressure will not drop much unless you use it for long full trigger duration.. (all this is said assuming you are using the impact gun for 3/8 or 1/2 drive impact gun. If you are working on large stuff like cats and semi's with 3/4 drive sockets, you may need the 1/2 hose. If you are spraying paint or using a continuous feed tool as a grinder, etc, you want to go with a minimum 3/8" short pigtail off the 1/2" hose with the larger high volume fittings if possible.)

    Hope this helps

    Practicing at practical wood working


    • #3
      Re: fitting question on a air compressor

      Certainly sounds like a fitting question for the forum.

      In most cases, the regulator fitting would probably be 1/4 NPT. But as mentioned by Gofor, they do come in different sizes. But of the three "consumer" compressors that I've had, the 1/4 NPT has been the standard.

      I hope this helps,



      • #4
        Re: fitting question on a air compressor

        regulators are rated in cubic feet just like tools are,

        it what they can pass and regulate, with any rate of accuracy,

        I have regulators that have holes or pipe thread fittings from 1/4 (may be one 1/8th inch) up to 1 1/4 inch pipe threads, the small ones are only good for small flows

        My oppion is,

        I would suggest finding a regulator with at least 3/8" preferable 1/2" pipe threads, it will have the capacity to regulate the air on the 3/4 impact wrench,
        it will do very good on lesser amounts as well,

        having an over capacity in this situation is much better than just meeting the need or under capacity, or this is my experence, I have one regulator on a special comprssor I jsut made that has a 1 1/4" threads on it, (same insides as they use on this companys 1" model and found new on ebay for penneys on the dollar), and it works well with large volumes of air 100cfm or small under 10 cfm) and on my shop compressor, I miss orderd regulator one time, and it had 1/2" threads, and not sure of the rating but worked so much better for my air tools than the 1/4 regulators I had been using,

        this is a crude explanation but simply there is a diagram in a case, and on one side it is supported by a spring and the spring is adjusted by a screw, the other side is supported by the air pressure, if the air pressure drops, it opens a valve, (usually a tapered needle) and if it meet the pressure it closes the valve, or hole. now to have flow it has to designed to meet the flow so the valve and needle needs to be able to flow the air through it, the better regulation is just as it opens, and if it drops a lot is not a very regulated flow,

        (the 1/2 air hose I bought had 3/8" ends on it )

        any perment air piping in the building (DO NOT USE PLASTIC PIPE), I think should be 1/2" or
        even larger, put drop legs (mositure traps under the tees to the out lets on the air),
        Attached Files
        Push sticks/blocks Save Fingers
        "The true measure of a man is how he treats someone who can do him absolutely no good."
        attributed to Samuel Johnson
        PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and the current state of the economy............the light at the end of the tunnel, has been turned off.