drip leg

[Sumboodie]

Right off the compressor tank, does it make sense to put a drip leg?

Setup is 80 gallon compressor, feeding into a 60 gallon compressor, then feeding to an air dryer, and for now just a hose off the dryer for air. Eventually it'll be 3/4" line going underground to another building.

Should I put a drip leg off each compressor? Like in my drawering?

 

[larry4406]

No drawering attached.

 

[Sumboodie]

And yes, I'm a hell of a drawererer.

Dunno if it matters to feed compressor #2 from top or side of the 4 way. Or do 2 Tees instead?. Ideally it'd have 2 3/4" ports on the tank, but it only has the 1. Just a bottom shelf homejobber Husky unit, so built to a low price point. Was $499 in 2006... tag is still on it

The one for the pressure gauge is only 1/4", as is the drain.

 

[larry4406]

My gut feel says yes to drip legs.

 

[willf650]

I always did it with a 1/4" petcock on every instillation I did. It was mainly instrumentation air compressors I installed.

The drip legs were always full when I stopped in the mech rooms and cracked them open.

 

[Sumboodie]

I always did it with a 1/4" petcock on every instillation I did. It was mainly instrumentation air compressors I installed.

The drip legs were always full when I stopped in the mech rooms and cracked them open.

Wasn't sure if it made sense to have one right after the compressor as the air in the tank vs air a foot into the pipe is pretty much same temp, so wouldn't figure that much water dropping out. But that's why I'm asking.

With the air dryer in place, probably doesn't matter a whole lot, but it's only rated to 22cfm, and if both compressors would be running, it's more around 30cfm. Plus removing water before it gets that far is better.

I'm fairly stocked up on 3/4" pipe, valves and fittings. Some of it is from a setup I helped tear apart years ago, so finally able to use it after tripping over it for 10+ years.
Probably could do 1/2" even, but I'd have to buy everything.

For the drip legs, was just going to use a 3/4" valve with a hose barb on the end attached to a clear hose. Will probably feed all the drains to a pail, since if I put it to outside, it'll probably freeze. And rather not have it dumping gross oily water on the floor

 

[Sumboodie]

When I tie it into the shop, I may add a buffer tank. I've got 2 or 3 smaller compressors I can use.

 

[Twisted Sid]

The title of this thread with that sticker figure drawing is a good match

 

[Sumboodie]

The title of this thread with that sticker figure drawing is a good match

I ran out of paper when making the stick man me.

 

[Beerhippie]

I'd use a coalescing filter after the main compressor tank instead of the drip leg. Depending on what kind of compressor you have, there could be significant oil in the air. Air dryers generally don't play well with oil.

 

[no704]

Yes and please put drain ***** on them! In an industrial building i had to plug in an air hose to a never used air drop. Got a nice shower of delicious smelling “water “!

 

[Sumboodie]

I'd use a coalescing filter after the main compressor tank instead of the drip leg. Depending on what kind of compressor you have, there could be significant oil in the air. Air dryers generally don't play well with oil.

commercial grade Campbell Hausfeld from the early 80s. Similar to an R15 pump.

Got 2 on order, a 5 micron and regulator for 1st and a 0.01 micron for 2nd. (I have to regulate down, 2nd tank is only a 150 psi max)

 

[The Cobbler]

the farther down the pipe run the better in my opinion.
it's probably going to be more effective right at the inlet of the drier, and only one would be needed

 

[danielbuck]

me personally, I would put the drier and water traps inbetween the compressor and the 1st tank. might as well try to keep the water out of the tanks to begin with. A drip leg before the dryer probably won't do all that much, it will really only work well if the air has been cooled and the water condenses out of the air. a water trap after the cooler (however you cool it) would probably work alot better, but not as cheap as a simple drop.

I use a transmission cooler and electric fan inbetween the compressor and my 60 gallon tank, it works very well. Main water trap right after the cooler, it gets a ton of water out of the system. My water traps down stream of the tank never have any water in them anymore. And the tank purge valve itself never blasts out water unless I've been running it while it's raining and super humid outside, more than can condense out of it with the cooler and trap.

 

[Steve_P]

If you are going to put in drip legs, filters, separators..... they need to be as far from the compressor as possible for maximum benefit to give the air chance to cool so the moisture can turn to liquid and separate out. You'll catch 50X more water 50 feet away than you will 1 foot away.

 

[Sumboodie]

me personally, I would put the drier and water traps inbetween the compressor and the 1st tank. might as well try to keep the water out of the tanks to begin with. A drip leg before the dryer probably won't do all that much, it will really only work well if the air has been cooled and the water condenses out of the air. a water trap after the cooler (however you cool it) would probably work alot better, but not as cheap as a simple drop.

I use a transmission cooler and electric fan inbetween the compressor and my 60 gallon tank, it works very well. Main water trap right after the cooler, it gets a ton of water out of the system. My water traps down stream of the tank never have any water in them anymore. And the tank purge valve itself never blasts out water unless I've been running it while it's raining and super humid outside, more than can condense out of it with the cooler and trap.

The dryer isn't designed to handle air that is hot like that. Need a high temp dryer, which is several grand.

 

[danielbuck]

The dryer isn't designed to handle air that is hot like that. Need a high temp dryer, which is several grand.

What about just a radiator and fan to cool and condense? it's pretty cheap to do. I doubt I put $150 into my radiator and fan setup if you were to buy the parts new. Could run the dryer after that if you wanted it even more dry. The air coming out of the radiator in my setup is basically ambient temperature, maybe just a bit warmer. the air going into the radiator is so hot I can't even touch the lines.

I just think air systems are better when you do some measures to keep water out of the tanks themselves.

 

[Sumboodie]

What about just a radiator and fan to cool and condense? it's pretty cheap to do. I doubt I put $150 into my radiator and fan setup if you were to buy the parts new. Could run the dryer after that if you wanted it even more dry. The air coming out of the radiator in my setup is basically ambient temperature, maybe just a bit warmer. the air going into the radiator is so hot I can't even touch the lines.

I just think air systems are better when you do some measures to keep water out of the tanks themselves.

Compressor already has a cooler on it.

 

[Firebrick43]

Compressor already has a cooler on it.

Isn't that an intercooler between the low pressure 1st stage piston/s and the 2nd stage high pressure pistons?

 

[Sumboodie]

Isn't that an intercooler between the low pressure 1st stage piston/s and the 2nd stage high pressure pistons?

Between pump and tank as well.

 

[Sumboodie]

Got these. Regulator after big compressor and fine mist seperator after little compressor.

One thing I was thinking. Was happens if air flows in reverse through a Regulator?

If the big compressor doesn't kick on, it's possible the little compressor would flow air to it.

I suppose I could put a check valve, though rather not add more things if not needed.

 

[DaveAndStuff]

The dryer isn't designed to handle air that is hot like that. Need a high temp dryer, which is several grand.

Is it a dryer or an after-cooler?

 

[Sumboodie]

Is it a dryer or an after-cooler?

Dryer. Has a heat exchanger and r134. Like a fridge.

Aftercooler is on the big compressor. It just goes pump,cooler, tank.

 

[danielbuck]

Dryer. Has a heat exchanger and r134. Like a fridge.

Aftercooler is on the big compressor. It just goes pump,cooler, tank.

is there a water trap at all inbetween the cooler and the tank? if not, the cooler is useless to keep water out of the tank.

 

[Sumboodie]

is there a water trap at all inbetween the cooler and the tank? if not, the cooler is useless to keep water out of the tank.

No. Never seen one done like that. Not sure why but I'd imagine the compressor engineers know better than I do.

 

[Beerhippie]

is there a water trap at all inbetween the cooler and the tank? if not, the cooler is useless to keep water out of the tank.

Seems the reservoir is the water trap.

 

[Citation]

No. Never seen one done like that. Not sure why but I'd imagine the compressor engineers know better than I do.

I've seen a number of people on here who do the "oil cooler" after cooler after the pump, before the receiver. Since the oil cooler is where the air is being cooled that's a good place to install a water trap. When we did my brother's DIY system we put a water trap after the after cooler. It catches quite a bit of water that doesn't end up in the receiver. He's been quite happy with the setup for the painting he has done.

 

[mm08822]

The dryer isn't designed to handle air that is hot like that. Need a high temp dryer, which is several grand.

Look into Quincy for high temp air dryers. It was pricey for me so I defaulted to the lower temp unit. Sorry I dont recall the pricing but easy enough to find on line.

 

[mm08822]

No drawering attached.

Is drawering the art of making drawers?

 

[mm08822]

A few ideas I always wanted to try but never made it to the top of the list:

Aftercooler wall version using finned baseboard copper tube with auto drains pulsing.

Adding a large diameter copper or pex tubing coil right off the compressor head and placing the coil into a 15 or 55 gallon drum filled with water. Lower part of coil has t that is connected to drain line with auto drain cycling. Sure the water will get hot eventually but still has some cooling and moisture drop-out ability before pre-dryer filters.
Of course the water needs chemicals to prevent micro growth.

If coil is plastic (pex or other) then would probably be best on output of compressor tank.

 

[larry4406]

Is drawering the art of making drawers?

I was being a smart *** and quoted his first post (he forgot to include his “drawering”).

 

[mm08822]

I was being a smart *** and quoted his first post (he forgot to include his “drawering”).

And believe it or not, likewise!

 

[Sumboodie]

I've seen a number of people on here who do the "oil cooler" after cooler after the pump, before the receiver. Since the oil cooler is where the air is being cooled that's a good place to install a water trap. When we did my brother's DIY system we put a water trap after the after cooler. It catches quite a bit of water that doesn't end up in the receiver. He's been quite happy with the setup for the painting he has done.

I'm talking about factory setups though. None I've seen have any sort of drain. I'd imagine there's a reason.

 

[Sumboodie]

Look into Quincy for high temp air dryers. It was pricey for me so I defaulted to the lower temp unit. Sorry I dont recall the pricing but easy enough to find on line.

I have no reason to spend $4000 on one. A $700 one that is before the air output to final use point will work too. and even that cost more than I paid for both of the compressors. I don't care if the tank has water or not. It drains. Tank is 45 years old and still near 100% thickness.. I'm pretty sure it'll outlive me.

 

[danielbuck]

I'm talking about factory setups though. None I've seen have any sort of drain. I'd imagine there's a reason.

cost. and they would probably love to have your tank rot out after 10 years so you have to buy a new one.

 

[Sumboodie]

cost. and they would probably love to have your tank rot out after 10 years so you have to buy a new one.

Last one i worked on was around $25,000, and that's consideted fairly cheap.

15 hp with 4cylinder pump.

I can't imagine they'd not include a maybe $200 auto drain on the aftercooler if it was needed. The tank already did.

 

[danielbuck]

just because it was $25,000 doesn't mean the pinch pennys where they can. Look at decently built vehicles, they cut costs all over the place and still cost $40-$60k or whatever. if they can save $4 per chassis, they will. Plastic coolant pipes on the back sides of motors that are hard to get too when (not if) they crack and leak? why not make it out of Aluminum like the rest of the engine. (Toyota... looking at you!). cost, I imagine.


Any way, sorry to derail. If it were ME and my setup, I would put a radiator and auto drain before the first tank. but it's your setup, run what you want . Schedule the drain in the tank to purge often.

 

[Sumboodie]

A

just because it was $25,000 doesn't mean the pinch pennys where they can. Look at decently built vehicles, they cut costs all over the place and still cost $40-$60k or whatever. if they can save $4 per chassis, they will. Plastic coolant pipes on the back sides of motors that are hard to get too when (not if) they crack and leak? why not make it out of Aluminum like the rest of the engine. (Toyota... looking at you!). cost, I imagine.


Any way, sorry to derail. If it were ME and my setup, I would put a radiator and auto drain before the first tank. but it's your setup, run what you want . Schedule the drain in the tank to purge often.

Already is one. Im not redoing factory stuff to add a drain though.

 

[Sumboodie]

Are pressure gauges that read sideways not common? Or I guess the feed is on the side vs bottom? I've really only used back and bottom mount in the past.

The one on the small compressor broke when I moved and it feeds from the right side. It was just a cheap thing anyhow, I generally use liquid filled gauges.

I have a normal bottom mount one that'll work, but haven't found a decent side mount (I guess that's the name?). Not a huge deal, just had me wondering.

https://www.amazon.com/dp/B0BCYMDY5M?tag=atomicindus08-20

 

[Beerhippie]

Are pressure gauges that read sideways not common?

You can generally specify the stem location--bottom, back, left or right side--when you order from a good supplier. You won't find that selection at the hardware store. You'll be lucky if they have bottom and back, and even luckier if they have different stem sizes.