Air line piping from compressor?

by quailbraker
(Wenatchee Wa)

If my air compressor discharge port is 1/2" do I have to make my air line piping system 1/2" also ? Would 3/4" help any or would it be about the same. Run probably 100 feet or so?

Well quailbraker, that's a good question!

There would be some definite negatives to plumbing a smaller air line from your compressor than the discharge pipe size.

It would be like turning your garden hose faucet on only half way. You would get less flow out the nozzle.

By plumbing the air line smaller than the discharge pipe size, you are restricting air flow into the plant. That may negatively affect the operation of air tools, as you may have reduced the flow to the point where they cannot run properly due to lack of air.

There is no downside to making the line from the discharge larger than the discharge pipe size. In fact, big plants do it all the time, by plumbing from the air compressor up to a 3" or 4" main on the ceiling.

What the larger pipe becomes is another compressed air reservoir.

Just be aware that the larger the pipe, the more water is likely to condense out in it, and you do want to have compressed air filters (water traps) at all points of compressed air use.



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Installation of copper compressed air lines

by mike wells
(st. louis, mo)

In home shop applications would it be better to braise or soft solder lines and fittings?
Hi Mike. Thanks for the question.

Since I'm not used to brazing, I sweat my copper with solder, and that works just fine for me.

If you think about it, the pressure that the copper lines and joints will see from most DIY type air compressors is in the 150 PSI range, max.

There's no concern about a soldered joint letting go at those, relatively, low pressures.

On the other hand, if you prefer to braze, go for it.

Far as I'm concerned both will work well, and you should opt for the method that you're most comfortable with, and costs you the least.

Congrats on selecting the higher cost option for plumbing your air lines....copper tube or pipe. Over the long haul, I'm convinced that the payback will be there in less "crud" ending up in your air tools or valves and cylinders.



Comment from Paul:

If you braze, the copper sweat pipe loses strength (not the joint) due to the high torch temperatures. The only place braze might be more appropriate is at the discharge point of the compressor where the temperature is realtively high, which generally goes directly to a receiving tank by unjointed tubing or by pipe. At the receiving tank, heat is dissipated by the tank wall, so supply air has a lower temperature, which solder joints would not be affected by. Solder with silver content gives a stronger/higher temperature joint(cost more).
Thanks Paul, we appreciate the input.


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