Thread: Water Extraction from Airline

I bought an old stuffed compressor for $30, just for the tank.
I use it as a 2nd receiver with a long flexible hose between the 2 tanks.
The long hose & the 2 tanks lets the air cool & any moisture condense.
Works for me.

Originally Posted by Cliff Rogers

I bought an old stuffed compressor for $30, just for the tank.
I use it as a 2nd receiver with a long flexible hose between the 2 tanks.
The long hose & the 2 tanks lets the air cool & any moisture condense.
Works for me.

The second tank option is something thats also suggested in the thread I referenced. Id prefer to have pipework on the wall though as it takes up much less space (and I don't have a lot of it spare!!) and I hope should be more than enough for my needs.

Rather than coming out of the tank, take the line direct from the pump and then back into the tank. That way you get rid of the moisture/condensation before it gets to the tank.

If headroom is a problem, just run the pipes diagonally across the wall - works the same way.

What you are trying to do with this is cool the compressed air down before it gets to the tank so all the moisture has condensed out. You could go up and come down in a zigzag if you didn't have enough vertical height.

Michael

I'd be inclined to put the water trap where ever you have outlets. Run the main pipe up high onto a "T" or elbow at the end, and about halfway down put another "T" facing out for your airline outlet, at the bottom of the "T" run a pipe approx 800 mm long with a ball valve to let out any moisture, 1/2" should be fine as most of it would be caught in the air receiver, make sure you drain the tank daily. I ran a factory with mainly air equipment on a set up like this, overall about 100 metres of 1/2" pipe. Where spraying was involved the "T" halfway down was fitted with another "T" with air regulator and an outlet for unregulated air.
Kryn

Originally Posted by nearnexus

If headroom is a problem, just run the pipes diagonally across the wall - works the same way.

or put more in vertically...its the pipe od surface area you want...(but make sure the pipe size is not restrictive non the less )

Soundman posted this in that thread
"I say again DO NOT...DO NOT used annealed copper pipe for air lines.....on the surface it may seem to be capable of doing the job, but it is not."

if used on air compressor systems running at <than 200psi cut out pressure, I do not see a problem

I use annealed copper pipe on air conditioning systems which has the potential to run at discharge pressures of >500psi eg 410a systems
and yes while it can work harden, fasten it at regular intervals so that it doesnt jive (rattle roll and shake)..that prevents the work hardening effect. Keep unsupported (compressor to wall) piping as short as possible (even if using flexible piping).

18g cu refrigeration pipe is suitable/rated for pressures up to 400psi...this is run pressures & not test pressures
(the only difference, as far as I am aware, between refrigeration and plumbers cu pipe of equal size and gauge is the refrigeration grade is cleaned and dehydrated).

if using cu and you are brazing do not use anything else but brown tip (15%)...some on here will say yellow tip is okay, and it may well be for low pressure stuff (like water) but it is not suitable for higher pressures

cu has better heat transfer and wont rust internally like steel.

I wouldnt use anything else but cu pipe...i seem to have an abundance of it around my shed

Originally Posted by eskimo

Soundman posted this in that thread
"I say again DO NOT...DO NOT used annealed copper pipe for air lines.....on the surface it may seem to be capable of doing the job, but it is not."

if used on air compressor systems running at <than 200psi cut out pressure, I do not see a problem

I use annealed copper pipe on air conditioning systems which has the potential to run at discharge pressures of >500psi eg 410a systems
and yes while it can work harden, fasten it at regular intervals so that it doesnt jive (rattle roll and shake)..that prevents the work hardening effect. Keep unsupported (compressor to wall) piping as short as possible (even if using flexible piping).

18g cu refrigeration pipe is suitable/rated for pressures up to 400psi...this is run pressures & not test pressures
(the only difference, as far as I am aware, between refrigeration and plumbers cu pipe of equal size and gauge is the refrigeration grade is cleaned and dehydrated).

if using cu and you are brazing do not use anything else but brown tip (15%)...some on here will say yellow tip is okay, and it may well be for low pressure stuff (like water) but it is not suitable for higher pressures

cu has better heat transfer and wont rust internally like steel.

I wouldnt use anything else but cu pipe...i seem to have an abundance of it around my shed

Thanks for this... Its interesting peoples view on copper pipe in this application, seems to be very pro and very anti.

Having said that, I'll be using steel pipe. Given the advice and reading Ive done, I suspect 3 x vertical runs (due to my limited headroom), each with a drain tap at the bottom before feeding into the tank.

I also like the idea of Kryn's post, running steel pipe to the outlets and having a localised drain below each outlet - this is what my father did in his workshop 30 years ago in the UK - seemed to work well enough for him (If memory serves me right he also had a large copper coil in-between the compressor and tank, but his compressor shed was outside and he had lots of space).

R
J

Originally Posted by eskimo

18g cu refrigeration pipe is suitable/rated for pressures up to 400psi...this is run pressures & not test pressures
(the only difference, as far as I am aware, between refrigeration and plumbers cu pipe of equal size and gauge is the refrigeration grade is cleaned and dehydrated).

Just to back that up - the safe working pressure for "normal" AS1432 C-grade (lowest grade) DN 20 annealed cu tubing is 500psi. A-Grade is over 800 psi.

There are two ways to separate the water or a combination of both, (besides a drier of course). The air can be cooled or it can be slowed down by running into a bigger vessel before it enters into the main distribution system. My pick would be to get a small compressed air tank and put it in an old fridge. Drill through the walls for the inlet, outlet and water drain and you have an el cheapo refrigerated drier. The big problem with most home systems is due to the small pipe size usually used (1/2"/12mm) the air speed is too high through the pipe and the water stays in suspension. 3/4" is in only just big enough to minimise the problem.

Originally Posted by Vernonv

Just to back that up - the safe working pressure for "normal" AS1432 C-grade (lowest grade) DN 20 annealed cu tubing is 500psi. A-Grade is over 800 psi.

Thanks Vernon
I knew my figures conservative...just couldnt be bothered looking it up...lol

Ventureoverload
Just use your 3 verticals into a horizontal headers top and bottom

Here is a simple water trap I have on the todo list.
My compressor is outside the shed so I am thinking of installing this outside as well onto the side of the shed.
The vertical height is about 1.5 m

Following a tip from cba-melb, I purchased an automatic variable electrically powered solenoid tank vent valve like this
http://www.ebay.com/itm/1-2-2-way-Au...E:L:OC:AU:3160

For intermittent compressor use the auto vent valve it is very effective at minimising the amount of water, but for continuos use I am still thinking of using something like the water trap above.

BTW using a 1" diameter pipe connected to a 2" pipe will make very little difference to cooling at the sorts of pressures and flow rates found on a normal compressor.
[EDIT] that's only correct in a static case, in a dynamic situation it depends on the flow rate/overall pressure drop ; more calcs needed.
A pressure differential can be generated between the two pipes by inserting a small orifice or pressure regulator between them but that will restrict the flow rate.

Originally Posted by ventureoverland

Having said that, I'll be using steel pipe. Given the advice and reading Ive done

Why would you want to use a material that rusts and introduces debris (rust) into the system. Fair enough it was used in the old days but they stopped using it in water systems 50 years ago for good reasons and one was rust and corrosion. Using steel makes an easy job hard and introduces known problems before you start.