Compressor piping

[Torque1st]

The first blast will knock most of the initial water out. More water will accumulate tho. I usually try to anticipate and do things right the first time when it is easiest to do. The idea of a pit inside the building is what I was calling a dry well. The bottom is gravel so that water will drain. The cost of a tee and a short section of large PVC pipe is negligible.

The pit or dry well can be used for your electric entry also.

Are you going to bring water to your barn? The same pit can be used for your freeze proof hydrant. To get down below the frost line around this are means going about 3' deep. Call the codes department or county at your location.

 

[Richard Givan]

I'm not sure I follow all the stuff about the drain, but, speaking as a shade-tree physicist, I like the idea of a 30-gal tank in the remote location fed by a 1/2" line. The remote tank would serve like a big capacitor in an electrical circuit, smoothing out high surges in air demand. The supply would be continuous through the supply line until the pressure was fully up in the tank. Unless you were running something continuous like a sand blaster, that smallish line should work fine, in my opinion.

As to the drain, could you install one of those valves like the ones used to turn off water below the freeze line? Maybe run a section of empty poly or pvc pipe as an airtube from the valve out the top so you could hear when the water is expelled and air is shooting out. Then you could crack the valve until the water is gone. Put some gravel underneath it to drain, and purge the water every day you put use on the remote line. After traveling that far through the coolness of the ground, the air should be quite dry when it gets to the end, but drops of water will condense and run to the low point of the line. I can see it filling the line with water during times of high humidity if you don't contrive some way to rid it.

 

[mmg440]

...

The pit or dry well can be used for your electric entry also.

Are you going to bring water to your barn? The same pit can be used for your freeze proof hydrant. To get down below the frost line around this are means going about 3' deep. Call the codes department or county at your location.

I have thought about water service also. But don't know if it's worth the hassle or not for this building anyway. It is about 10 feet or so lower then the garage that is already lower then the septic. If I ran water it would only be used seasonally like maybe a water spigot for a hose. I don't have any plans to heat this building except installing a stack for the single barrel wood burner I already have stored in the building. So any water service would have to be winterized every year and probably would be a real pita. even with a freeze proof hydrant.

 

[Richard Givan]

In order to avoid possible confusion, I spoke of using a water valve, but only for the purpose of draining your compressor line of water condensation. I see your problem of the lowest point in the line being underground, and was thinking of a means to crack a valve from above.

BTW, I bought 1/2" copper line in 10' lengths yesterday for $5.32 each, if memory serves, so the price has come down from the madness of last summer, at least some.

 

[mmg440]

In order to avoid possible confusion, I spoke of using a water valve, but only for the purpose of draining your compressor line of water condensation. I see your problem of the lowest point in the line being underground, and was thinking of a means to crack a valve from above.

BTW, I bought 1/2" copper line in 10' lengths yesterday for $5.32 each, if memory serves, so the price has come down from the madness of last summer, at least some.

I was responding to the subject with water that Torque1st brought up with the same trench for water service just lower below the freeze line.. I don't believe there was any confusion with your water valve

 

[Steve in Mi]

BTW, I bought 1/2" copper line in 10' lengths yesterday for $5.32 each, if memory serves, so the price has come down from the madness of last summer, at least some.

That is good news! IIRC the retail was $6. and $10. for 1/2" and 3/4" before the prices skyrocketed. Prices below these probably reflect the currant economy/slump.

 

[jbarila]

I work in a power plant maintenance department. The plants blood is its air supply and we have low to high pressure systems. Heres the deal on iron vs copper.
Both are used. Copper is fine up to about 150 psi if silver soldered. It will hold more pressure but Code will only allow it up to 150 psi. Black iron pipe is widely used and funny code rates it to 150 psi if it is schedual 80 thickness. The bottom line is black iron is much cheeper to buy but costs a little more on installation costs. ie the fittings are more expensive and threading is labor cost. Copper on the other hand takes skill to silver solder but it is much faster to install. Copper lines are used if the air supply must be supplied clean. No matter what is said there is some corrosion in Iron piping inside and out. Copper stays cleaner and does not required painting to prevent corrosion.
Thats it in a nut shell! For garage use either will work fine. Paint the Iron or buff the copper, it really comes down to personal preference.
My 5 cents worth.
JB

 

[Steve in Mi]

JB the codes you speak of I suspect are some internal company codes.

As I pointed out to e-tek a long time ago when it comes to black iron fittings, there are at least two classes of fittings (125 MWP and 150 MWP) for pipe that are rated below 175 psi.. I refer you to McMaster-Carr if want to varify this, http://www.mcmaster.com/# . If you will be using a 2 stage compressor capable of 175 psi be sure your fittings are rated for it. What is the pressure rating on the fittings from your local hardware or Big Box store? What I see on the shelf are not marked and asking the store help gets a big, dah. I gotta wonder what some folks are using in their air supply piping systems. Be safe.

 

[akdiesel]

Pick up a "Pocket Reference" book at any hardware store. It will have all of the ratings for all pipe and tubing as well as lots of other very usefull info.

 

[Torque1st]

I have thought about water service also. But don't know if it's worth the hassle or not for this building anyway. It is about 10 feet or so lower then the garage that is already lower then the septic. If I ran water it would only be used seasonally like maybe a water spigot for a hose. I don't have any plans to heat this building except installing a stack for the single barrel wood burner I already have stored in the building. So any water service would have to be winterized every year and probably would be a real pita. even with a freeze proof hydrant.

Use this type of water hydrant:
http://www.guineafowl.com/fritsfarm/greenhouse/hydrant.html
Your air line should be below the frost line also.

 

[walrus]

JB the codes you speak of I suspect are some internal company codes.

As I pointed out to e-tek a long time ago when it comes to black iron fittings, there are at least two classes of fittings (125 MWP and 150 MWP) for pipe that are rated below 175 psi.

Most air compressors in repair shops that I've seen have been plumbed with 150 lb fittings. Never seen an issue with it but 300 lb fittings would be better. Burst pressure on sch 40 blk iron is way over 175 psi

 

[Torque1st]

The pressure ratings for fittings are for working pressure. The working pressure takes into account environmental stress from temperature extremes, corrosion allowances, defects, damage, and physical stress on the fittings due to; alignment, support, and over-tightening, etc.

 

[walrus]

here's a chart with working and burst pressure for sch 40 pipe
http://www.engineeringtoolbox.com/wrought-steel-pipe-bursting-pressure-d_1123.html

 

[ktm450]

I have read that for compressed air the joints should be brazed or a "special" solder should be used. If sweat soldering, what exactly is the correct solder to use?

from some industry data I recently read, the choice is a 95% tin, 5% antimony solder or brazing. Standard tin/lead 50/50 solder has a much lower working pressure, and while brazing seems like a good idea, the temps are high enough that the pipe is annealed and the working pressure goes down on the pipe.

For example for 3/4" pipe 150F max temp the following working pressures are shown

Solder tin/lead 50/50 150psi
Tin/antimony 95/5 625psi

for a brazed joint, the pipe becomes the limiting factor. For instance with type L pipe 3/4" brazed joint has a working pressure of 450psi @150F. the problem is that the temp required to braze anneals the pipe and drops the pipe from 1002psi as drawn down to 450psi after anealing.

So, looks like the 95/5 solder is the best choice followed by brazing. In any case I wouldn't use std 50/50 solder, joint strength is to low with a two stage compressor.

there are other solders listed with even higher strength, if needed.

reference is copper tube handbook from the copper development association

 

[MarkH]

The age old cost of iron vs copper. Prices are in flux. When I took all of the parts to put my system together over 2 years. First copper was cheaper then iron when I did it copper was cheaper. So there does not seem to be a constant answer.

Do one and enjoy it.

The other piece of advice I give everyone is to prepare for the cost. The cost of the distribution system with multiple drops, filters, regulators, dryers, etc can easily come to the same amount you spend on the compressor. Just like the compressor doing it right is essential to enjoying the system. Budget what you spent or plan to spend for your compressor and you most likely will not get to much of a budget overrun shock to explain. Your air will also be clean and dry enough for anything you want to do. Cutting corners usually will have other costs. One screwed up paint job is more expensive than doing it right initially.

Second with filters, to work effectively, bigger is not always better, it usually does not drop all of the water out of the air.

 

[69charged]

i used 1/2" copper for mine. the only thing i regret is installing it at just above waist height. i will redo it this summer right at the ceiling. when you go to hang anything on the wall, you have to be concious of that line there. i would think that a person can talk themselves out of using whatever someone suggests so i think a person should go based on price. i mean, all this stuff that people have mentioned would work for you. whatever you find easiest and cheapest. i love sweating copper. i do it at work lots so i find it quick and easy. i did my garage in a day easily. and i bought the copper in 20' lengths. i would post up a pic but idont have any right now.
clarence