/diy/ - Do It Yourself

Forgot to add there labeling on the motor says copeland, Sydney Ohio. But the stamp on the air container says "Toledo FAB and Welding" along with some max psi and "Made in the USA year 1963"

Here's the model number:
"KAK4-0075-IAA" there's a small gap then a "C" then what looks like the manufacturers number but the label is worn off. The second number is "68D 04376"
Pic related

Here's a pic of where the oil was leaking out with the cheese cloth over it. I was going to put some galvanized pipe and an air filter for a lawn mower on it but the threads dot appear to be NPT. The OD is about 1.5"

Last pic. Not sure what this part is? Hopefully someone can help me out. Thanks guys.

Where did you find this, bottom of ocean?

>>822636
The two tubes on top of cylinder are most likely your intake / exhaust. So, in this poorly rotated photo, it's the smallish tube on the left. You'll want to get some sort of filter on that.

>>822635
This, I suspect, is where the oil goes, as well as missing cap with dipstick. Suspect that you're getting ring blowback and it's puking oil out of this fill pipe everywhere else. Sticking a coat hanger down there will verify that you're hitting bottom of crankcase. You'll want to get this plugged off. I'd suggest, short term, finding a plastic cap (milk jug cap looks close) and threading it on.

>>822634
Is this seriously the best pic you can get?

>>822652
Yea it's the best pic I can get just because it's so faded. It doesn't really make a difference. I posted the numbers that I could see on there. So I should filter the top part and cap off the bottom part? I'll check with a coat hanger. I dot think a milk cap is big enough as it's about 1.5" OD.
How would I go about puting a filter on the top if it's not threaded? Should I Tap it or just get a slightly smaller pipe to attach the filter to

Thank you by the way

You know, I'll use a lot of things that are rusty, but a pressurized tank just isn't one of them. Good luck OP, hope you don't live in my neighborhood

>>822671
He means because its blurry as hell. FOCUS

I'm inclined to agree with >>822673
Be careful OP.
/diy/ is slow as it is.

>>822671
Filter top, cap bottom.

The filter isn't going anywhere, b/c in operation the thing is sucking air. A press fit over a rubber ring would be sufficient. The only reason to clamp down is so it doesn't fall off when being moved. If you can't find anything immediately I wouldn't sweat it for just testing / firing up, just don't put it to use.

As for the cap, suspect there's air pressure behind it or I'd tell you to use a rubber cork. You could try it anyway. Use your imagination...

I've never seen a pancake compressor that old... that's not a typical tank size from that era. Those really didn't become a thing until the '80s. What are you planning to do with it?

>>822673
If it was a boiler I'd totally agree.

This is just an air compressor. If you want to be really safe, fire it up behind a wall. My main concern would be that the pressure switch was functioning.

I suspect, though, that this thing is going to hit a lower pressure bound (~100 - 120 PSI) and stop charging, just based on it's outward condition. At that point it won't trip the pressure switch, and will just keep running while building no more pressure.

If the above happens, OP, unplug it. You'll either need to reset the pressure switch or rebuild the pump.

Story time:
> Old compressor sitting in granddad's shop
> Obviously handmade. Cylinder with lightly bulged endcaps. Went up to 120 PSI or so before shutting off.
> Hey granddad, what's the story with that?
> Your dad built that in his teens. It's an old fridge compressor and motor
> How'd he get the endplates like that?
> Dunno.
> Ask dad about it later
> Oh, those sides were straight when I welded it up.
> To test it, I took it to work. The shop guys charged it to 200 PSI. We figured if it didn't explode, it was built well enough.
> The endplates bulged, but it didn't leak, so I used it.

>>822701
I just want to use it for menial shit like dusting off woodworking and maybe a small phuematic too. It's been fired up to 120psi but I haven't used it yet. I'll try finding a cap for the oil. Does the oil cap need to have a hole in it at all?

Don't fuck with this thing. Too dangerous. That rusty tank lets go and you could get hurt.

>>822753
It's not weak anywhere. I think it was cast iron. It's really thick. I feel safe using it

>>822753
Oh eff off. This is your expert opinion based on what? Some shitty pics? What do you really know about this pressure vessel, or the potential failure modes?

OP, just make sure the pressure switch works, the pressure blow-off valve works. Pull the lower plug and drain any water from the tank.

As for the cap, no idea. If it's building pressure behind I'm be tempted to drill a hole in cap rather than trying to maintain a seal. Perhaps you should plug with a rubber cork and see what happens first... that will tell you if it's building back pressure and is a harmless failure mode (vs. a metal cap flying around.)

>>822756
It's not cast iron, but the way it feels like that is b/c it's really old, and is probably totally overbuilt. Somewhere on it should be stamped a pressure rating. I'm betting it was rated to 2X max pressure, and in reality would be OK up to 4X. There are ways to test these things, but frankly it's a waste of resources. Just use it.

>>822760
Thanks. Only reason I ask is from googling some air compressor oil caps have a hole on them. When it was turned on when the cheese cloth was over oil pipe it didn't shoot out oil but kind of pulsated like a women's vagina when she comes. Not really that intense enough to spit out oil

>>822766
Interesting analogy. You could probably run it either way in that case. Really only one way to find out. Have fun.

>>822774
Thanks for all the help bro.

>>822631


hmm copeland makes AC compressors.. and that looks like an old style AC compressor that someone mounted to a tank and converted it into an air compressor. my guess is this is some nigger rigged contraption and thats why you cant find info on it... and that does look alot like an AC compressor ive seen a few of those styles before

>>822631
>>822830

shit I forgot the pic. this is similar to what you have on that thing. it is indeed an AC compressor and someone mounted it to a tank and made an air compressor out of it.. and probably added that fitting to keep it oiled, because without the refrigerant present to circulate the oil, the compressor will eventually seize up.. and this was their way to add oil to it

>>822832
Interesting. I wonder if it's possible then to replace the oil cap fitting if it was just an add on extra then.

So I started it up and plugged it in ip to 120psi. I think I should get a regulator for it just to be safe. Going to return some parts because the filter doesn't need that many.

One thing I noticed is that there was air pushing out around the rubber stopper where the oil cap is supposed to be. Not sure how to rectify this. If I do install a regulator would it just go inline next to the pressure gauge or somewhere else?

Haha the stupid oil cap fitting unscrews. I'll be able to plug it easy.

>>822864
The regulator should be that round thing that the cord goes into and out of. It will also have a fitting off the tank to monitor pressure. It may be adjustable, see if you can remove the lid.

>>822903
There's a pressure gauge in line to monitor it, but i don't know what the regulator is set to. It looks like it does come apart there's a flat head screw holding the circular cap on. I'll check it out when I get home.
Thanks guys. This is turning into an interesting project that's not expensive either. It's fun learning about this stuff.

>>822916
Also anyone know what the CFM at a certain pressure might be for something like this? Not sure how to find it I've tried googling the copeland AC compressor CFM
>>822832

this thing is a piece of shit.. throw that bitch into a dumpster somewhere and go buy a modern and safer unit that thing just screams safety hazard

>>823196
How is it a safety hazard?
>muh surface rust
It's fine

>>823134
Its going to be low. You could run a nail gun, blasdt air around or into tires. Run an impasct gun. You're not going to have volume to run a spray gun, ferinsrance. I've really no idea how you'd calculate this, but probably a function of tank volume and fill time/pressure.

>>823220
I would scrape it off and paint it. But that's me.

So I actually took the compressor off the tank, and looked at what was said to be the pressure regulator. I'm not sure how it works though. I'm gonna clean the tank up then prime it with some rusty metal primer then recoat it,

>>823288
Thus the plan. I'm not sure what this box does if the circular thing is the pressure regulator.

>>823301
Here is it opened

>>823287
That's fine that's exactly what I'm looking for, not interested in spraying paint. Mostly air, framing nailer and smaller phuemantic tools.

>>823305

looks like the capacitor for the motor start windings

>>823317
Idk what that means haha. If the circular housing holds the pressure regulator how do you set it to a certain pressure?

>>823196
>buy

>>822711
Is this the pressure switch?
>>823300

>>823300
There's also writings on the cap

>>823300
That's the pressure switch. Helps that it says it on the cap. Google it up, but suspect that that flathead screw turns in and out to set terminal pressure. You will need to play with the compressor a bit to figure out how to get it to shut off at the right pressure. I don't know the rating but 120 - 140 psi is a good terminal range. There's also a lower pressure when compressor will start... This may just be a function of terminal pressure ( say 50 psi below max). Again, googhle it up.

While we are on topic, you should install a pressure regulator. That allows tank to charge to max pressure, while running tools at design pressure, say 90psi. Nailers are sensitive to this, for example. For filling tires, won't matter.

>>823305
That is the starting capacitor. Look it up. If motor won't start and hums this is blown. You should know what it is and what it does, but leave alone for now.

Rustleum brush on is exactly what I'd use on that tank. Would paint tank red or blue and compressor flat black. Again, just me.

>>823348
Just looked at this closer. If I'm reading right its meant to charge to 150 psi and restart at 95 psi. The other numbers may be an adjustment range, not sure. I'd try letting it run up to 150 psi and see if it shuts off... Expect it will, assuming it wasn't adjusted from factory.

>>823370
Thanks for all the help bro. Where would I even install a regulator? Inline with the pressur gauge?

>>823403
At the last point between the compressor and the line you're going to connect to it. It should have a set of guages on it, one to read tank pressure and one to read line pressure.

>>823514
Here is a cheapy $5. Single guage reads outlet pressure. The dual guage unit I saw was complete with switching/power control. I'd keep the electrics you have as long as they work... Vintage and much cooler looking.

http://pages.ebay.com/link/?nav=item.view&alt=web&id=400531927897

>>823220
You can't really judge the integrity of a container from its outward appearance. The inside of compressor tanks are moist environments. They rust from the inside out. Plenty of compressor tanks with "just a little surface rust" have been shredded by air rapidly expanding to 6-8 times its pressurised volume, and being close to one when it happens is no joke. Is there any way you can inspect the inside of the tank? Look closely at the drain plug. There have been instances where the drain plug is set too far in, so the inlet is set higher than the bottom of the tank, meaning it will never completely drain. This, admittedly, is rare. What is not rare is to forget to drain every once in a while after using it for a day. Every once in a while X five decades = quite a lot of time with a pool of water in the tank. Also, just because it doesn't blow up the first or fifth time you fire it up, doesn't mean it won't blow the tenth.

99% sure it's fine, but think about it: would you risk standing close to a grenade with a 1% chance of exploding, for a 99% chance to score a compressor, and a shitty one at that?

It's an old repurposed HVAC compressor, not a purpose-built air compressor. Tank is likely quite well-lubed but you could always not use the tank and connect the thing to a BBQ LP jug. You can unscrew the valve after venting the LP, then look inside with a flashlight to inspect, and finally add a fill valve and a blowoff if you really want to. I can't overpressure mine with my 5HP compressor (look up tank pressure ratings if you like, I don't recall them at the moment) so I just use a ball valve and air chuck as many thousands of people have done for decades.

Your air will smell like mercaptan odorant which is amusing if you want to stank up an area then watch your bros get paranoid thinking it's an LP leak.

>>823543

>It's an old repurposed HVAC compressor, not a purpose-built air compressor.

this was established long ago maybe if you read up further you would see.

see:

>>822830
>>822832

but ill give you a 2/10 for effort

>>823537
When I drained it it was mostly air and the smallest amount of water. The drain plug is on the very bottom of the tank so when it's up right water has no place to go but in the drain plug.

Hardware store was out of the paint on rust reformer so I got a wire brush, some elbow grease and went to town. Then used the rusty metal spray primer.

>>823664
>When I drained it it was mostly air and the smallest amount of water
That... doesn't really tell you anything about the condition of the tank.

Also, the drain plug being at the bottom of the tank is no guarantee that the nipple doesn't protrude into the tank. I've tried to draw it, it's hard to explain. If that drawing makes sense, know that this mistake has been made by engineers working for companies who produce compressors. Would you put it past Joe Schmo who ghetto rigged your compressor to make this mistake?

>>823690
Oh I see what you mean. I didn't hear any water. It's a chance I'm willing to take considering it's been used by friends for years

>>823522
Also link doesn't work bro. Says it's been over 90 days old so it was dropped

>>822711
>This is just an air compressor.

you don't know much about pressure vessels, do you? 100 psi is more than enough to seriously injure or kill you if the vessel decides to let go. ever see what happens to someone when they stand next to a semi-truck tire that blows out? they get fucked up, and heavy truck tires "only" run about 100 psi.

Got a couple coats of paint on it

>>823746
Suppose the tank is defective and it does have a hole, why is it going to explode instead of just releasing all the air like it's normally designed to do when you drain the tank?

>>823762
Might do a clear coat on too for added protection. Thoughts?

>>823706
I just tried it, its fine. If not, eBay air compressor regulator.

>>823768
Depends on paint, but I wouldn't bother. That can cause as much trouble as anything. Looks much better now BTW. Fwiw I always wire bush this kind of thing prior to paint. I don't trust the paint over rust materials.

>>823774
I wirebrushed the hell out of it. There was still a little bit left. I should have gotten the drill attachment wire brush instead of the actual brush. I'm doing the compressor now. Then it's just replacing the bolts if I want to (depends on cost of stainless) and replacing the copper tubing that I broke. Haha

>>823690
If you really want to dig into this tank, you could remove that giant square plug on the tank and check inside with a flashlight. That bwill give you an idea what it looks like. Don't think for a secvondbthat will satisfy anyone here though. They won't be happy until you've had it professionally hydro tested.

I'd just run it. Pinhole rust failure mode will be a stream of air out in case of corrosion. Catastrophic failure of welds is a big deal... So don't over pressure the tank, right?

>>823777
I've a 4 inch angle grinder with steel brush, but I also have the drill size one. Its incredibly handy for this size stuff, and cheap.

>>823779
It's not even worth it. Like I said I've seen it run up to 120psi and it was fine, and super quiet at that. Thanks for all your help though KG. I'll look into a regulator that I can put infront of the pressure gauge

>>823763

if it's rusted enough to develop a hole, then the tank is probably on the verge of rusting through in several other places which means that the structural integrity has been compromised.

like i said, you really have no idea how dangerous "only" 100 psi is. i've seen faulty pressure vessels explode at work. something as small as an air compressor tank can kill you very easily.

>>823789
If it's rusted enough to develop a hole, would the tank not bend, or give at the weak spots? When I filled then drained the tank at 120psi there was a very small amount of water that came out, but none of it was rusty

>>823827
http://youtu.be/KVP_A7eGYxw

In the event of an explosion, it will give at the weak spot, which will serve as an initiation point for a tear that will open the tank like a rocket propelled zipper, but any yielding might only be noticeable 0.01 seconds before lift off. This could prove to be insufficient time to depressurise the tank, run away or even whistle more than a few wavelengths of sound.

Exploding air compressors is a rare thing, for precisely the same reason planes almost never fall out of the sky: they are both so inherently dangerous that manufacturers make triple sure that it doesn't go to shit. Redundant fail-safes everywhere. Since your compressor has been made by a respectable brand and have been subject to a rigorous maintenance regimen under careful government supervision, it should be fine. Just kidding. Yours was Macgyvered by... someone, from pieces scavenged from trash, fifty years ago, and have been irregularly used by many people with varying degrees of competence.

I'm not going to say that this thing will kill you, it probably won't. Just... with all due respect, please be careful.

>>823844
>use a longer hose and dont stand right next to an active pressure vessel. especially one of questionable integrity

>>823844
>Live stram incase it kills you

>>823827
when pressure vessels fail, they usually fail catastrophically and rip open.

So it's a little new expensive ($25 vs $5) but I was thinking about using 3/8" stainless gas line that's coated to prevent rust instead of the copper line that was there before. The way the tank is set up the copper goes over the compressor from the tank to the compressor fitting so it has to bend a little bit. Some googling said this is a bad idea because natural gas is rated for a low pressure but I can't imagine that a flare fitting to NPT is going to be the problem and the line is bigger than 1/4" copper tubing that was there before

>>824068
Yeah, you'd mentioned that it had copper. Copper would be what I would have used for this but apparently it worked. Also, doesn't rust.

I think this ones up to you. But I'd stay low buck on this guy... $25 is a lot for just lines.

>>824185
Would=wouldn't. But as I think on it, copper is what they use in the HVAC application, and I'm betting guy that buikt thus was an HVAC tech.

>>824187
I went with the gas like just because to do copper it would have to forcefully be bent over the compressor. With the line I have some leeway.

>>824068
>the line is bigger than 1/4" copper tubing that was there before
Not sure if I understand you correctly, but if it's relevant, recall that generally speaking a thin tube can take higher pressure than a thick one. It is actually the ratio of the wall thickness and the inner diameter that decides, which means that a copper tube with a wall thickness of 2mm and inner diameter of 6mm will take more pressure than a copper tube with the same wall thickness but inner diameter 8mm. If you replace a tube in a pressure system with a larger diameter tube, make sure that the wall thickness also increase sufficiently to make up for it.

Also, regarding copper, stainless steel, cast iron etc.: I can't remember the context, but I was once made aware of the importance of chemical compatability when various metals are being used to make a machine or vessel. I think there was a ship or something where critical components were fastened with bolts that were technically excellent, but somehow ended up acting as inadvertent sacrificial anodes for the rest of the construction, so they failed very quickly. I seem to remember that the metals in question was indeed copper and stainless, but I know very little about this, so maybe someone can fill in?

>>824321
Thanks bro. I was referring more to the fact that copper tubing is stiff and it has to bend in a poor way to get to the fittings (see OP pic)
As it was explained to me it's best to use similar metals (no brass tubing unfortunately) but the big thing is galvanized steel and copper with water. There's some process of electrolysis when the three are together that erodes the metal. I'm not too keen on the details though.

Decided to put a castor on the front. Unfortunately the one that was big enough didn't have holes that matched up. Best way seemed to be to use JB weld. First time working with the stuff but it seems like I could have gotten better results with polyutherene liquid nails. So far this bj weld is a pain in the ass

>>824675
Forgot pic

Here's the new air output line. Just bought a new reducing bushing and nipple. Everything else is the same except for the pressure regulator. It's by Bosch and was $10 off amazon. Nice because it goes up to 160psi like the rain bird

>>824679
Shit forgot pic again

>>824677
Looking much better.

Why are you filling air in the bottom fitting? That fitting is meant to have a removable plug. You remove it every so often (ranging from every use to every year depending on your level of maintenance) to drain out the water that fills these tanks over time.

>>824694
Was the Rainbird gauge on there originally? That's a really nice gauge... This beast really is an odd collection of parts...

>>824720
>>824722
I'm not filling air from the bottom. That's the drain plug. It's got copper pipe to the drain valve tee. It's upside down to let the jb weld dry to the castor and tank leg.

The rain bird was on there when I got it but i don't think it was a stock part. Seems cool. It's the ones that's filled with liquid

>>824724
Gotcha.

There are no stock parts on that guy. Someone bought a professionally made pressure canister and likely welded the support brackets to hold a repurposed HVAC compressor. The then tubed it up with parts from era. Its 60s diy.

This is what a "blast injury" looks like. One of the most common causes of this injury is pressurized tank failure. I saw a guy two months ago who was doing the SAME FUCKING THING YOU ARE. He was in the attic of a house using an old air compressor, standing next to it when the tank ruptured. It blew both of his legs into splinters, and the tank was only like 30 gallons.

Do you have any FUCKING idea how painful a blast injury is? You can buy a new tank for less than $100 bucks. Attach it to the old compressor, and you're good to roll.


You have any idea how much money it costs to open both of your legs up surgically, take all of the pieces of bone out with a pair of tweezers, and reconstruct each bone while you're under anesthesia.... ?

Don't be a moron!

>>824735
This is like a 5 gallon tank, and all the rust was surface rust only. I'll take my chances and not be feet from the tank

>>824735
Fucking this. I got a Craftsman air compressor off craigslist for free. I noticed the drain was rusty after I got it home. Eventually looked inside and there was about 1" of rust on the bottom of the tank.

I mean like 1" thick. The walls of the whole tank was fucked. Drilled two holes in it and gave it to some scrappers.

That tank was in a LOT better shape than yours op.

Fill it with water when you pressurize it. When it fails it will be a lot less exciting. Still could totally be dangerous and loud, but it might not land in your neighbor's yard.

>>824741
You really have no way to judge it was 'surface rust'

take all the plumbing out and look inside the tank, you will shit a brick.

>>824741
Lol. 150 psi is 150 psi. Doesn't matter if it's 5 gallons or 20 gallons. +40 psi in your ear could give you a brain hemmorage and kill you. 8 psi in the throat could blow out your bowels. Then there's the shrapnel.

>>824750
All compressors will rust from the inside too. It's been covered already

>>823337
This is gonna be op when the tank pops

>>824750
How can I not? I was able to get the majority off in 10min with a wire brush.
Emptying the tank after it was at 100psi yielded air and a very small amount of condensation with zero rust in it.

> ask advice
> ignore warnings
> spend hours making shiny and new looking
> buy new parts, fix oil leaks, etc
> fire it up, works
> realize 5 gal air compressors are stupid because they run constantly when you use them
> comes on twice putting air in bike tire
> tank finally explodes
> lay in hospital bed thinking about 15 people saying it wasn't safe

>>824769
Such is life

There's a reason professional tanks have expiration dates on them.

Well merry fucking Christmas /diy/ I finished it and plugged it in and the compressor doesn't start. There's a wire terminal loose but idk where it goes. I'll check on it tomorrow.

>>824819
Haha. Just figured it out. It took a bit to charge up but the pressure switch kicked in at 120psi. Might change that to 150. There were 2 small air leaks at the flare fittings on the gas line but I was only able to hand tighten those.

>>824819
Mechanical Engineer here. You're going to blow your legs off. I know a lady who does prosthetics, would you like her number now or later?

>>824823
And why is that? Guy I got it from used it for years with no problems. All i did was make it safer

>>824827
Please try to remember to come back and post pics after it's popped.

>>824827
Why do you want prosthetics? Well I hadn't thought about wheel a chair option but that is also available to you. Did you replace the tank? If the answer is no then no you didn't make it safer.

>>824827
Why do you want prosthetics? Well I hadn't thought about a wheel chair option but that is also available to you. Did you replace the tank? If the answer is no then no you didn't make it safer.

>>824827

The guy you got it from previously didn't suffer tank failure. You're asking for it.

>>823646
You have zero reading comprehension don't you? That post is pointing out that because it's a repurposed tank it was at one point well lubricated => less rust. It goes on to point out that a new tank could solve the possible problems.

>>824827
>All i did was make it safer

Despite everyone telling you otherwise, people with actual experience of tank explosions and the injuries they can cause, telling you otherwise...you still seem to believe this?

I guess the "Sunk Cost Fallacy" is kicking in.

>>824923
No I understand the risks, but I think it's nill for a tank that's been used with zero problems, and only had surface rust. what would convince you guys? Firing it up and leaving it at 150psi for a day?

>>824819
Also surprised no one had brought up my cypress Slabs just sitting there

>>822760
What's the pressure blow off valve? There's a giant hex bolt about half way threaded into the tank with a nut. Is that it?

>>824972
Proofing vessels is usually done hydrostatically to twice their working pressure, so you'd need 220 240 or 300 psi, and for it to be full of water so it doesn't kill you when it fails.

>>824986
So i would basically need some sort of hydrostatic compressor? I'm assuming it's more than filling it with water and turning it on, which I'm not going todo btw

>>824993
Okay 166%, not 200%
Its too bad you wont do it because it is the only thing that will make us stop laughing at you.

http://en.m.wikipedia.org/wiki/Hydrostatic_test

Forgot link

>>824977
Pressure blow off valve... you don't have one on that thing. It's a valve that blow off pressure once tank hits a certain point (usually slightly above target charge pressure.) They let out air in the case that the motor doesn't switch off at 150 PSI like it's supposed to. It would be usually installed between tank and pressure regulator, but, really, anywhere on the tank will work. Most types I've seen are resetable, I believe they also make 1-time use models that blow out and need replaced. You want the former. Example:

http://www.ebay.com/itm/New-1-2-NPT-150-PSI-Air-Compressor-Safety-Relief-Pressure-Valve-Tank-Pop-Off-/290967515459

>>824993
To do this, you fill the tank with water, then pressurize the water. There are ghetto DIY-ways to do this with a pressure washer that I'll let you research, but the right way is with a tool plumbers have that can charge up to 600 PSI, for testing water pipes. The reason you use water is that it's incompressible, so if/when vessel fails it just gushes water out; it doesn't explode as it would in case of air.

>>825018
Yea I guess new compressors use this as the same as the drain valve too? Atleast the craftsman I've used seemed like it. So it would go in like with the regulator?

>>825000
Why do I need a pressure washer to fill it? Can't I just fill it with water manually and start the compressor?

Also this is what I was thinking of. What's this?

>>825026
Looks vestigial.

I've been building air compressors out of scavenged parts since I was a teenager. OP kinda scares me. He's done zero research into what he has or how a compressor is normally set up and why.

>Flex gas line
Jesus

>>824972
>I think the chances of an old pressure vessel that I haven't tested failing catastrophically is nil

Sure.

>>825099
What's wrong with gas
line? Its actually more expensive than the regular line used but it's all the hardware store had. The thing had copper tubing on it before. And the hardware store didn't have anything besides those two. It works fine?

And I test it, what do I have to do? Full it up and increase the pressure to 300psi? If I can do it without any other tools sure I'll do it.

>>825026
Also what does this bolt do? I feel like it's just an extra hole that was tapped

>>825131

It probably is just an extra hole. Holes in pressure vessels are usually a tapered pipe thread, so having a straight bolt just screwed in there makes me nervous.

Speaking of making me nervous:

- The gas line. Use a much shorter piece of flexible copper. Copper bends any way you want it to as long as you know what you're doing or have the right tools.

- No blow off valve. If that ancient pressure switch sticks that tank will blow you up regardless of how clean it is.

- The age of the pressure switch.

- The pressure you're using. I don't know about AC compressors, but single-stage air compressors really are happiest around 120-130 PSI max.

- Not using an unloader valve. Probably not a big deal on a unit that side but it helps your compressor live longer.

- The tank, both its condition and the fact someone might have done some DIY welding to it. I can't tell.

>>825136
>>825126
>>825131


Also, I can't tell if you'tre using a check valve on the tank inlet or not. You should be.

Gas flex line isn't used at these pressures and it's not designed for much vibration. It also has more internal volume than you want. Nearly every air compressor ever built uses copper line.

Easiest way to pressure test the tank is to plug all the holes, fill it up with water, get every air bubble out, then connect a grease gun via a pipe also filled with water. If you got all the air out you'd be able to pressurize it to 300 pounds in a few pumps.

>>825136
I can easily get a blow off valve. I was going to put it where the bolt/nut are but I guess I can't cause it's SAE and not NPT. Can you tell me why I should use copper? Or what's wrong with NG line. Everyone in person I've asked seems to think either is fine.

Unloaded valve? Is that the same as the drain valve that empties the tank because there is one.

I plan on operating it at around 120psi. That's where the pressure switch kicks in

>>825143
Okay so from the line from the compressor to the tank there should be a check valve? I might go with copper because it is cheaper, it's just the copper it had before was bent over the the compressor in a shitty way and that seemed like the only way to do it

>>825126
>the hardware store didn't have anything besides those two. It works fine?

Uh, is that actually a fuel rated hose?

>>825214
It's for natural gas.

>>825163
Also what do I need to bend copper without flattening it? Some copper type conduit bender or just a multitool

>>825216
You realise natural gas runs at stupidly low pressure? That hose is in no way rated for the kind of pressure you're talking about.

>>825159

You sure that hole is SAE and not just a fucked up NPT?

An unloader valve is a part of pressure switches that runs a second smaller are line to somewhere along the main pressure line. When the switch shuts off the compressor is depressurizes the feed line so the compressor doesn't have to start against a load.

>>825216

Are you so thick you can't use Google? This is worse than asking for sauce on /a/. Copper tubing can be bent three ways. One is pack it with sand, two is use a spring bender, and three is a lever style bender.

Learn to search the internet. This thread would be half the length if you weren't asking people to spoon feed you.

This thread is getting scarier by the minute...

>>825227
I'll check again but I'm pretty sure it's not tapered and I don't see how the bowl would thread as well as it does if it were NPT. Yea I probably could have googled the copper pipe thing. I'm at work so I have to sneak this stuff on my phone...I'll look into an unloaded valve too, but will most likely get a BOV and out it after the regulator and go back to copper and call it a day. Still looking at ways to hydrostatically test it. What I dot understad is if I'm filling it with water then running te compressor why do I have to fill it with something like a pressure washer or some special tool?

Okay so here's a checklist:
I need a POV/BOV at around 160-200psi. It looks like there's MPT on the end of these. Will that screw in if I remover the ring?
Also need a check valve just before the tank.
And an optional unloader valve but if doesn't seem necessary. I don't think even the craftsmans of this size have one.
I also need to hydrostatically check the tank. Still googling that.

>>824321
Correct about wanting to make sure materials are compatible, especially in a wet environment, which compressor lines and tanks are, due to the water being compressed from the air.

The specific example you are looking for is likely either the HMS Alarm or the USS Independence, depending on the century you are thinking about.

More info: http://en.wikipedia.org/wiki/Galvanic_corrosion

>>825126
Typical gas flex line from HD is only rated to 5 psi.

http://www.homedepot.com/p/Unbranded-HOME-FLEX-1-2-in-x-25-ft-CSST-Corrugated-Stainless-Steel-Tubing-11-00525/203073939

>>825268
>>825268
I'm switching out to copper. I I have a question though. Does the POV/BOV have to go in line with the regulator/ output or can it be on a tee off of the main output?

>>825143
I've never heard this one before. Nice...

>>825274
Yea this is what I will probsbly try and do once I get it all set up.

>>825018
I got the same pov you listed but in 1/4" npt. Do you know if I can run a T after the regulator and have the top end be the pov and the other end be the outlet?

>>822760
Kg, I thought I posted it but I didn't. The tank has a plate stating that it's rated for a max pressure of 125LBS at 600 degrees F. How would I calculate the max pressure at traditional operating temperatures? Compressors heat the air to almost 200 degrees F no?

>>826069
>max pressure of 125LBS at 600 degrees F
Assuming you mean 125psi, the way you calculate the max pressure at traditional temperatures is you take 125psi and multiply it by a coefficient. This coefficient is 1. So 125psi times 1 equals 125psi, or 8.6 bar, and that's your max operating pressure at traditional temperatures.

Pressure is pressure is force over area. Temperature doesn't affect pressure. The temperature of a fixed amount of a given medium contained in a fixed volume will affect the specific pressure of that medium, but 125psi is 125psi at any temperature. Maybe compressors heat air to 200F, I don't know, but if it does all it means is that as the air in the tank cools to room temperature the pressure drops somewhat and the compressor might run a little to top it up. The 600F thing on your tank is just the manufacturer asking you not to expect the tank to hold up if you plan to use it on Venus. Actually, at 125psi internal pressure, the tank would implode on the Venutian surface, but I digress. The point is that steel loses strengthas temperature goes up. Jet fuel doesn't burn hot enough to melt steel, but it burns plenty hot enough to just about halve its yield strength. If I recall correctly, 500C (930F) is enough to halve the yield strength of mild steel. At 600F, we are entering into the realm where you can start to fuck with the tempering of common steel alloys, which will permanently affect the tank's ability to not explode. So that's what the 600F is about. I reckon.

>>826238
I hope it blows up and he can sit in a chair for the rest of his life thinking about this stupid thread. The only thing that would make it more satisfying would be if it killed YOU in the process.

>>826246
I've literally got all the safety precautions on this tank. A check valve, pressure switch, regulator, and pov valve. Idk why you think it's going to explode when I've already ran if before to test it and there was no pitting, or rust when I drained the tank. I goig to eventually test it with water and a grease gun to shut some of you guys up. Most of the pics are of the motor not even the actual tank.

>>826238
>The point is that steel loses strengthas temperature goes up. Jet fuel doesn't burn hot enough to melt steel

>>826246
Why would it be more satisfying if it killed me too? What did I do?

>>826419
You helped me out. /Diy/ wants me to not build this thing so bad.

>>826069
Take a photo of the plate and post it. The rating doesn't make sense as written.

>>822671
The photo is blurry as hell. Take another photo with flash, if you have flash, and steady the camera on something like a pole, chair, whatever. Make sure the camera is physically touching the item you are steadying it against.

A lot of times those metal plates are actually stamped with the letters. On those kinds you can rub some black substance across it to make the letters stand out.

>>826909
I was able to find the compressor. It's a copelamati 3/4hp compressor. It's made by a refrigeration company but the model is apparently not for refrigeration based on the info from copeland

>>826988
Copelematic*