Question about running air lines

[b.preston]

Hello, I am in the process of running my compressor air lines in my shop. I am using 3/4" copper pipe through out. I will be running a flexible line from the comp. to the 3/4 copper. My question is, if I use a 3/8 flex line to the 3/4 will this have an adverse effect on the air traveling down the line? I might mention the 3/8 line will be about 3ft.
Thanks Bob

 

[Motofixxer]

Technically yes. Would you notice the difference? Probably not. But I just went to a hydraulic hose place and had em make me a custom 3\4 hose. You can also find them I believe at tractor supply type places.

 

[b.preston]

I do have a shop that is not too far away that I believe could make the hose. It does make sense to not reduce the line right off the comp. thanks for the advice Bob.

 

[scarpozzi]

There are equations to calculate the loss...It's probably easier if you look up the gas line charts as they are really more specific about pressure drops as a result of pipe length and diameter. In agreement with Motofixer. You probably won't notice anything, but you just added a bottleneck right off the bat. I want to say 3/8" is pretty standard for air fittings/hoses and you could have run 1/2" copper and saved some money....but if you were ever to get a larger compressor with 3/4" output and want higher pressure, further away, you'll have less pressure drop due to the distance.

 

[sberry]

It wont mean much, the 3 ft is pretty short and likely have more than that on the other end after a regulator. I like the hyd line idea for a couple reasons, but one being its cheap and simple, comes with fittings clamps etc.

 

[HTGTS350]

I had 1/2 for about 2ft from the compressor and then upgraded to 3/4 and I noticed the difference at my blast cabinet, it cost me about $30 to upgrade to 3/4. I also had 1/2 for about 3 ft to the blast cabinet and it cost about $40 to upgrade to 3/4, between to 2 I spent $70 and I would do it again tomorrow for the gain In flow I got.

 

[J Persons]

TP Tools sells a 3/4" steel braided line made specifically for compressors. It's about $35.00 for a 3/4" X 12" line.

 

[78Bird]

Northern tool sells a chunk of 3/4 hydraulic hose that would work as a flexible connect. It's not too long, but if you can terminate the hard line right at the compressor you can make it work.

 

[Falcon67]

You can also get 36" hydraulic 3/4 line at a Tractor Supply, or have one made at about any hose dealer.

 

[akdiesel]

The only thing I see being an issue is it could JT. In other words it will cool down rapidly when entering the 3/4" line due to a pressure drop when high air demands are needed.
But most of you tools also use 3/8" or 1/4" fittings so there is also a restriction there.

 

[Winmon]

This is where I get confused on compressor lines/sizing. My compressor has a 1/2" outlet fitting on it so what advantage would there be in 3/4" hose to my 3/4" hardline?

 

[Fixnair]

At 100 PSI a3/4" pipe will flow something like 600 CFM. A 3/8 hose something like 125 CFM. Both figures are dependent on the length of the pipe. Longer pipe = less flow. Plus each fitting decreases flow. Eg. One 90 *elbow = 10 feet of pipe.
I don't know what kind of tools you will be using but I doubt you will be needing more than 3/8 hose can supply.
The maximum flow will be determined by the smallest restriction in the system.

 

[Motofixxer]

Most tanks have a large reducing bushing that can be replaced. Mine reduced to 1/2" also. I used a big socket, some elbow grease, and an impact to remove the bushing and got one from a plumbing supplier that reduced to 3/4". Cost me about $4 and some time.

If you have a welded in bushing, then your SOL unless you cut it out and replace it. Good luck on that.

Any restriction you remove is better. Also I would recommend using High Flow couplers like the Milton Type V. Do a search to read the tons of discussions already had regarding them. They will make a noticeable difference also.

 

[coljar]

What are you going to be doing in your shop? What kind of air tools will you be using? Blast cabinet?

 

[sberry]

My compressor has a 1/2" outlet fitting on it so what advantage would there be in 3/4" hose to my 3/4" hardline?
__________________

for long runs.

Technically yes. Would you notice the difference? Probably not.

This is likely pretty accurate, I think it might be a cheap way to feel a bit better about yourself.

The maximum flow will be determined by the smallest restriction in the system.

Plus the distance factor. 3/8 doe 2 ft before the regulator that connects to a 3/8 hose is something the operator could never notice.