1" galvanized air line

[LutzTD]

I got a great deal on some 20 ft lengths of 1" pipe. I want to pipe compressed air from an outbuilding to my shop. I see benders on craigs for $50, is it better to bend the pipe for the turns or use 90 degree fittings? I plan to bury this in the ground about 12" deep, should I lay bedding or something? The ground here is basically just sand with a little soil on top.

 

[DHS]

I got a great deal on some 20 ft lengths of 1" pipe. I want to pipe compressed air from an outbuilding to my shop. I see benders on craigs for $50, is it better to bend the pipe for the turns or use 90 degree fittings? I plan to bury this in the ground about 12" deep, should I lay bedding or something? The ground here is basically just sand with a little soil on top.

I would not bending it but it can be done. Been a while since I messed with 1" but I think you can bend it in between two trees if your piece is long enough. Also I would not worry about bedding or anything. Install it test for leaks with soapy water and bury. We are lucky enough around here to have sand to work in.

 

[pattenp]

Don't forget to provide an access point on the buried line at the lowest point to drain collected water.

 

[Tim The Tool Man]

Is this galvanized iron pipe or just electrical conduit? I ask because you mentioned about bending it. Bending iron pie works to a point but the stuff is actually quite brittle and will crack or snap = leak. Slight bending between trees as mentioned is all you should expect. If it is electrical conduit, it is not going to work for air.

 

[Norcal]

20 foot sticks of 1" galvy pipe? Galvy, & black pipe come in 21' sticks. I would not bury galvanized air lines, but it really does depend on local soil conditions.

 

[buzz4041]

Good score. First off do not bend galvanized pipe to be used for airlines. Use proper fittings for changes in direction. The galvanizing will flake on the inside if bent. If you use it underground it needs to be wrapped with a protective tape or coated with coal tar epoxy to protect it from the elements. Just for your info galvanized airline is the prefered selection of materials for all the major oil companies in their plants all over the world. I have installed many many miles of this including in my own shop. It withstands rust on both the interior and exterior.

 

[Burtonrider10022]

Why the FK would you want to bend iron pipe? That sounds like a ridiculous amount of work when fittings are so easy! Not to mention, the fittings and a bottle of pipe dope will probably cost you less than the bender.

 

[LutzTD]

Why the FK would you want to bend iron pipe? That sounds like a ridiculous amount of work when fittings are so easy! Not to mention, the fittings and a bottle of pipe dope will probably cost you less than the bender.

mostly because of pressure drops at the 90 degree fittings.

this is galvanized iron pipe not conduit. The guy had

9 - 20 foot lengths
1 - 19 foot lengths
2 - 18 foot lengths
6 - 8-10 foot lengths
4 - 5 foot lengths

it is appearently air line taken down from a factory or something. silly me didnt jump on it the first time the advert was posted. By the time I got there there was only 6 20 footers and the 6 8-10 and 4 5 foot lengths. all for $150, just the 20ft pipe was worth twice that

I will get fittings, just thought a nice clean roundoff bend would be less pressure drop

 

[LutzTD]

I would not bending it but it can be done. Been a while since I messed with 1" but I think you can bend it in between two trees if your piece is long enough. Also I would not worry about bedding or anything. Install it test for leaks with soapy water and bury. We are lucky enough around here to have sand to work in.

thanx yeah I was thinking the guys in the north put them in a bed of sand, my whole yard is a bed of sand......

I will likely 45 the layout, that will shorten the run and 2 45s should be less pressure drop than a 90.

 

[EOC_Jason]

Being 1" you will have a considerable amount of air volume / pressure just in your line, I wouldn't worry about any significant pressure drop with a few 90's... I've only run 3/4" and that has been MORE than adequate even for a good sized machine shop.

 

[buzz4041]

You will never see any pressure drop in a little shop system like you are describing with 1".

 

[ford33]

Galvanized piped is not recommended for compressed air lines. Zinc coating inside the pipe will wear off over time and contaminate the air system. You will have zinc particles in your filters or air tools unless you filter it out. If you do install it, put a good filter in the garage to catch the particles and damage your tools.

 

[RECox286]

I have been using a galvanized piped air distribution system for over

30 years in my garage. It gets used on a regular basis, and in all that

time there has been no contamination show up in any of the water traps.

I have been using pretty much the same tools for almost as long as the

pipe has been in service, and there is no contamination that I can

discover. I know, b/c I occasionally do a thorough cleaning (disassembly)

of the tools that get the most use, and therefore would be the likely-est

to gum up. Hope this quells the "do not use galvanized" theory. (Albeit,

I believe that it is still OK to let engine oil do its' job for 100k mi. before

needing to change just the filter, and other such "shop myths".)

I also have some swampland available in Fla available for sale...

Stick with fittings, rather than bending the pipe. Fittings are very

cheap at the big box stores, (they come from China) and the cutting and

threading can be accomplished with rented equipment, or by a plumber

all at once, when you have all the cuts spec'd out. I would not worry

about pressure loss with 3/4 or 1" pipe/fittings, it will be negligible,

honestly. As far as laying the pipe in sand, no problem there either, but

you may want to top the pipe with 5/4 CCA (greenwood) to provide a

bit of extra protection from pothole type cave-ins which can put stress

on the pipe. (optional)

Uncle Bob

 

[LutzTD]

I have been using a galvanized piped air distribution system for over

30 years in my garage. It gets used on a regular basis, and in all that

time there has been no contamination show up in any of the water traps.

I have been using pretty much the same tools for almost as long as the

pipe has been in service, and there is no contamination that I can

discover. I know, b/c I occasionally do a thorough cleaning (disassembly)

of the tools that get the most use, and therefore would be the likely-est

to gum up. Hope this quells the "do not use galvanized" theory. (Albeit,

I believe that it is still OK to let engine oil do its' job for 100k mi. before

needing to change just the filter, and other such "shop myths".)

I also have some swampland available in Fla available for sale...

Stick with fittings, rather than bending the pipe. Fittings are very

cheap at the big box stores, (they come from China) and the cutting and

threading can be accomplished with rented equipment, or by a plumber

all at once, when you have all the cuts spec'd out. I would not worry

about pressure loss with 3/4 or 1" pipe/fittings, it will be negligible,

honestly. As far as laying the pipe in sand, no problem there either, but

you may want to top the pipe with 5/4 CCA (greenwood) to provide a

bit of extra protection from pothole type cave-ins which can put stress

on the pipe. (optional)

Uncle Bob

are the big box fittings OK for 150PSI? the reason I ask is that in reviewing the fittings in McMaster Carr, it seems there are fitting that are not reted for 150PSI and others that are. The fittings themselves are quite a bit thicker. Maybe Im over thinking this, but I dont want to dig this thing up once its in the ground, Id also hate to have a fitting crack or break in the garage

 

[RECox286]

All my fittings came from the local hardware store (COO=China) and none

have bulged yet. No leaks either: I very carefully wrapped teflon tape 3x

around the male threads, and then applied plumbers pipe dope on top of the

tape. (Just like is done with high pressure gas cylinder valves.) 150 psi is

not considered to be 'high pressure'...Now when you get up to hydraulic

system pressure, 2000 psi and above, then you need to be careful about

which type fittings you use. You'll be fine with the common variety.

Uncle Bob

 

[KinzeMech]

You will be fine with common plumbing tees and elbows for your direction changes. The amount of pressure drop at an elbow depends on the velocity of the air in the plumbing. The faster the air is flowing, the more energy it takes to change directions. It's that energy usage that causes the drop in pressure.

Due to the size of 1" pipe, the air will not have near the velocity it would have had with 1/2" or even 3/4" pipe, therefore the pressure drop will be much less.

In the event you do find yourself with any pressure drop due to the length of the plumbing, or if you have to use a very large number of fittings, you can address that issue with a surge tank plumbed into the line in the second building.

It's already been mentioned, but it's worth emphasizing, you will want a drain from the lowest point of this line. In direct contact with earth will keep it quite cold. especially in winter, and result in condensation in that line.

The upshot is, provided you can drain the liquid, your second building should have very dry air.

 

[Andybull]

In our factory, our main lines were 2" galvanized, all the way down to 1/2". Some of these pipes were used over 39 years without a problem.

As far as burying, I would check the soil conditions in order to see if it's too acidic.

 

[LutzTD]

In our factory, our main lines were 2" galvanized, all the way down to 1/2". Some of these pipes were used over 39 years without a problem.

As far as burying, I would check the soil conditions in order to see if it's too acidic.

this is my hope, I have a very expensive (got really cheap on the bay) self draining condensate valve im going to bury in a can at the end of the underground run. The soil temp here is not that cold though, however it still should provide some cooling effect.

 

[c39er]

I have 1" galvanized lines too-20 years-absolutely no contamination issues.

 

[Norcal]

I have no issues w/ galvy or black pipe above ground, black pipe is really the "standard" for compressed air, but still do not like galvy pipe underground, but if pipe wrap tape is applied a little ways before it exits the ground and continues for a few inches above ground, it will prob do just fine. The zone where the pipe exits the ground is a common failure point due to corrosion w/ rigid steel electrical conduit.

 

[DHS]

Ay work we have miles of 2" galv water mains that been in the ground for 40+ yrs and rarely do we have a problem with corrosion causing leaks. What does start leaking due to corrosion it is usually at the beach where saltwater occasionally gets to it. The other area where we find leaks would at the threaded section. When threading you remove outside galv and it allows it to rust, and it is also thinner there. Again I would not worry about burying it straight into the sand with nothing extra done to it.

Also I recently seen some vintage pipe threading kits on craigslist also. Tampa Bay.

 

[Bib Overalls]

High humidity is a given in Florida and you can expect condensate in your lines. Your underground lines should slope down slightly in the direction of the air flow. Your drip leg should run down at the point where the line goes up into the building.

 

[BD1]

How long is the underground run gonna be ?? If you don't mind spending additional money, you can run the iron pipe inside PVC pipe and fittings. We have done this for black iron pipe for gas lines. You would need to run 3'' pvc.
It is a little tricky at the 90's where your measurement skills come into play.
Once the 1'' is stubbed above grade, a 3'' pvc cap is holesawed for iron pipe to go through and caulk. If you bring the pipe up outside the building you can
go the cap route or holesaw the pvc riser where you want the pipe to come out and place a pvc cap on top. By going out the side it may provide better weather proofing.

 

[LutzTD]

How long is the underground run gonna be ?? If you don't mind spending additional money, you can run the iron pipe inside PVC pipe and fittings. We have done this for black iron pipe for gas lines. You would need to run 3'' pvc.
It is a little tricky at the 90's where your measurement skills come into play.
Once the 1'' is stubbed above grade, a 3'' pvc cap is holesawed for iron pipe to go through and caulk. If you bring the pipe up outside the building you can
go the cap route or holesaw the pvc riser where you want the pipe to come out and place a pvc cap on top. By going out the side it may provide better weather proofing.

the run is about 50 feet. I need to go out a way to get under my future driveway, then turn to the buling. I was going to run the under the driveway portion in pipe. What I dont want is to make a critter highway/homestead in the pvc.

 

[buzz4041]

Galvanized piped is not recommended for compressed air lines. Zinc coating inside the pipe will wear off over time and contaminate the air system. You will have zinc particles in your filters or air tools unless you filter it out. If you do install it, put a good filter in the garage to catch the particles and damage your tools.

You need to tell all the engineers of the major oil companies about galvanized pipe not being recommended for compressed air lines so they can change out the million miles of this in their plants. Sorry fordd33 but you are 100% incorrect on this. Also all air systems require a good filtering system regardless of what material is used.

 

[FluxCore]

Good advise on considering condensate in the line....And yes, it fersure will form, and yes it's good that it will...BECAUSE; once condensed into water, it's easy to remove-providing you consider it in advance and design your piping run properly to deal with it.

Hopefully you can slope the line downwards on it's path to your shop....If so, just outside before it enters the shop install a buried 'T' fitting and plumb off it with 1/4" copper tubing.....run the tubing into your shop along with the airline, then install an electric auto blow down timer on the 1/4" tubing-or even a manual ball valve....from the timer/ball valve run 1/4" back outside and bend it downward toward the ground so it can vent off safely.

I use the electric timers both at work and at home...They do a great job of removing water from my compressor tanks and I never have to remember them.

I installed this one on my compressor I built just for my plasma cutter, plus a Motor Guard M-100 filter.

 

[onewaydave]

COO = China

I have a frost hydrant for the dog house. Its 5' down and I have had to replace the 90' elbow into it (not the hydrant side) twice. PITA digging 5' x 3-4' hole every 5 years because the galvanized fitting rusts out! (No its not black pipe.)

Dave.

 

[LutzTD]

Good advise on considering condensate in the line....And yes, it fersure will form, and yes it's good that it will...BECAUSE; once condensed into water, it's easy to remove-providing you consider it in advance and design your piping run properly to deal with it.

Hopefully you can slope the line downwards on it's path to your shop....If so, just outside before it enters the shop install a buried 'T' fitting and plumb off it with 1/4" copper tubing.....run the tubing into your shop along with the airline, then install an electric auto blow down timer on the 1/4" tubing-or even a manual ball valve....from the timer/ball valve run 1/4" back outside and bend it downward toward the ground so it can vent off safely.

I use the electric timers both at work and at home...They do a great job of removing water from my compressor tanks and I never have to remember them.

I installed this one on my compressor I built just for my plasma cutter, plus a Motor Guard M-100 filter.

where did you get your timer and exhaust valve?

 

[FluxCore]

LutxTD,

There are many places to buy them, and many styles....Granger, Northern Tool and others.

Here is my unit:

http://www.denlorstools.com/home/dt...ols_p5702s_electric_air_compressor_drain.html