Air Dryer System for compressor

C

Chris

Can someone please give me a run down of what i need to effectively remove moisture from the compressor lines. I just purchased a new 7.5hp 80 gallon compressor and im not sure where to start. What type of fittings,material wise, are best? What brand filters or air dryers are recommended and how many? Does brand of hose or material mater?

Thanks!
 
I was talking with a guy from Quincy compressors and he said that each elbow = 30ft of line. Said that is why people complain about pressure. They have the equivalent of 300ft of just elbows, not to mention all the other runs. Sounds like the key is too keep it short but have a good drying system.
 
AAE;32039 said:
I was talking with a guy from Quincy compressors and he said that each elbow = 30ft of line. Said that is why people complain about pressure. They have the equivalent of 300ft of just elbows, not to mention all the other runs. Sounds like the key is too keep it short but have a good drying system.
Click to expand...

He must have been a paint rep in his last life! He is far from correct.
Here is a handy webpage to calulate fitting and line loss
http://www.vanairsystems.com/Engineering_pressure-drop.php

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AAE;32039 said:
I was talking with a guy from Quincy compressors and he said that each elbow = 30ft of line. Said that is why people complain about pressure. They have the equivalent of 300ft of just elbows, not to mention all the other runs. Sounds like the key is too keep it short but have a good drying system.
Click to expand...

He must have been a paint rep in his last life! He is far from correct.

Here is a handy webpage to calculate fitting and line length

http://www.vanairsystems.com/Engineering_pressure-drop.php

now look at this chart and see how many cfm you effective pipe lenght will flow in CFM @ psi

http://docs.engineeringtoolbox.com/documents/1280/compressed-air-*****!******-capacity.png

For almost all hobbyist users 20cfm @ 150 psi is a high capacity compressor. Connect it with 3/4" id pipe and use full port ball valves and the amount of pressure drop will be almost nil. CFM flow capacity at the end of the line will be in the neighborhood of 100 cfm, Another way to look at it, 3/4" pipe and avoiding the use of globe valves and your piping configuration will not matter.


btw, not all ball valves are full port, many are not. How to tell? a full port valve will have the pipe id through the ball. Only kind to buy imho.
 
SOF,
Very interesting information. In the flow capacity chart it looks like a 1/2" pipe at 175 psi provides about the same flow (scfm) as 3/4" pipe provides at 125 psi.

On the page you reference, it looks like a standard 90-degree elbow is equivalent to 5.17 feet of that size pipe but the long sweep elbow is less than half that (2.41 feet). Of course that improvement comes at a cost: McMaster sells a short 1/2" copper water supply elbow for $0.49 but the same 1/2" elbow in long sweep is $2.85 (almost six times as much). In 3/4" copper the short sells for $1.12 and the long for $3.93 (only 3.5 times as much).
 
if a person is concerned about long sweep vs standard 90 flow rate there are a couple things to consider.
1: do not use a dwv sweep in place of a wrought long sweep.
2: 2 45's with a short pup between them will be almost as beneficial as the long sweep 90'.

I see no need to worry over it as 3/4" pipe or 1" pipe w/ 1/2 drop legs for shops will work just fine.

100 standard 90's + 100 feet of 3/4" pipe , 1 swing check, and 1 full port bv operating at 150 psi @ 20 cfm = pressure drop of .6psi
 
I run out of my compressor into 100 ft of copper type m line under the eve of my building outside. Then back in and to a La-man air dryer. (No dessicant just filters and a mechanical water catch kinda hard to explain. From their into a high volume regulator then to my guns. A thing to remember with driers is they are rated at a certain humidity usually at 72 degrees. So if you have a 50 cfm drier and a 50 cfm compressor and its 95 with 100% humidity the drier can no longer keep up. I only have about 20 cfm but I scored a super deal on a dryer so I run a 250 cfm drier and my air is as dry as the Sahara . also remember the run fro. The tank to the drier. Its is best to have a conductive line as long as possible to cool the air which makes the driers job that much easier.
 
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