5HP compressor shop air lines

[Lahti35]

I'm the proud owner of a Saylor Beall 5hp 80 gallon compressor and I'm in the process of planning my shop air lines... but stuck at what size pipe to use: 1/2 or 3/4.

The system will have two runs, one will be 30ft long and the other will be 20ft long. Both air outlets will have at most a 50ft hose attached when in use, they will not be used at the same time only one or the other on at any given time.

I plan on running a small sand blasting cabinet, a DA sander, and a plasma cutter. The outlet on the compressor is 3/4".

Plan A: All piping 3/4 inch.

Plan B: 1/2 drops (6ft max) 3/4 piping from compressor to drops.

Plan C: All piping 1/2 inch.

Which would be suitable for the tools in the small shop I have?

 

[CompressorPros.com]

You would be fine with 1/2", but might be easier with the fittings being 3/4".

 

[Finky198]

With air bigger is better go 3/4" it not like you ever going to have to replace it anyway.

I have a 3/4" hydraulic line from the compressor to our 1" Main line down to 1/2" drops for filters and reg. I've been Very happy we have excellent flow with minimal pressure drop (we also use 3/8" quick connects not the 1/4")

I think The biggest thing to remember is it's a system and any single thing can Change the flow. So try to keep it simple...

 

[gdocktor3]

I also go with the "bigger is better theory" when it comes to air. Use 1/2" for the drops and 3/4" for main.

 

[Davefr]

I saw the effects of line loss first hand:
http://www.garagejournal.com/forum/showthread.php?t=331011

Go advice - Go Big!!

 

[Superbec]

I would go 3/4 only to the blasting cabinet, then 1/2 for the rest will be more than enough.

 

[Lahti35]

Very good gents! Looks like 3/4" to 1/2 drops it is....

I'm planning on using 1/4 Milton V fittings, I hear good things about them.

 

[md21722]

1/2" flows about 100 SCFM and works great for many people. A full circle loop rather than dead ends is said to work best. If you are buying all new parts you may want to pay the bit extra and use 3/4" or 1" for the loop with 1/2" or 3/4" drops just to go premium. Some folks use super strut to secure the pipes to the walls or ceiling. Don't forget drip legs. FWIW, I have air tools that **** down 35 SCFM and get about 26 psi pressure drop through the filter, regulator, and 25' of 3/8" hose. If I switched that to 25' of 3/8" hose and big body 1/2" couplers it drops to about 18 psi.