Air Compressor - Header Size?
Air Compressor - Header Size?
(OP)
Air compressor: 175 cfm
120'-0" of header
7 stations
15 cfm needed at each station
stations consist of 3/4" drop, pressure regulator, quick connect
No more than 3 on at one time
To be used for running simple air tools
How do I go about sizing my 120'-0" of header?
Thanks.
120'-0" of header
7 stations
15 cfm needed at each station
stations consist of 3/4" drop, pressure regulator, quick connect
No more than 3 on at one time
To be used for running simple air tools
How do I go about sizing my 120'-0" of header?
Thanks.





RE: Air Compressor - Header Size?
Basically, you want to size your pipe so your piping pressure drops are minor. You've spent the money compressing the air, you don't want to lose lots of that pressure just flowing through your piping system.
dP per 100' for 1" sch 40 is 6.6 psi, too high IMO.
dP per 100' for 1 1/2" sch 40 pipe is about 0.73 psi.
dP per 100' for 2" sch 40 pipe is about 0.20 psi.
These are out of Crane's technical paper 410.
If you run sch 80 pipe, both dPs will increase by about 40% due to the smaller ID. For your system and assuming you see no need for more capacity in the future, the 1 1/2" should be fine. If you might increase air flow later, put in a 2".
RE: Air Compressor - Header Size?
So as general rule of thumb, size the header so that a mimimum pressure drop occurs, then add in an extra 15%-25% above the min. for future and capacity. As to which percentage to use, this is where experience comes into play based on the application.
Hope this helps.
saxon
RE: Air Compressor - Header Size?
TD2K said it all...
In my opinion, all air systems seem to be about the same general size and cover about the same general area. Your compressed air need seem to be on the more modest side...
All of the compressed air headers I have seen have been 2" hard-copper....except for one really, really big/plant, that had a 2-1/2" header
MJC