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Buying a used compressor

3K views 18 replies 5 participants last post by  deadbodyman 
#1 ·
I am supposed to meet a guy tomorrow to possibly purchase his vintage Saylor Beall compressor with a newer dayton motor. I read on here that this is a decent brand pump, and figure it could be a good buy. Thing is, I don't really know much about compressors. So i was hoping you guys could fill me in on some things to look for, so I don't dump my money into a bad investment.
Thanks
 
#2 ·
do you have one of those flexible wand inspection cameras... so you could check the inside of the tank for corrosion..

you will want to check the brackets and feet welded to the tank for signs of cracks.

with the compressor UNPLUGGED.. rock the compressor pulley back and forth every 1/4 turn to listen for loose rod bearing clearances... https://youtu.be/bmF1bfDLDFM what a rod knock looks like..

there is no easy way to check the valves and piston rings.. you will want to verify the Unloader works also.. along with the pressure relief valves.

on a 220 IR 5 horse unit in a different former shop who ever installed it used the pressure switch to control the motor.. it welded the contacts one day.. it was making strange noises.. lots of air leaks where the pressure relief valves were all open because the compressor was not shutting off.. it was still building pressure.. even with all the pressure relief valves open wide.. that was really scary to run into that room and turn off the power, not knowing how much pressure it had and if it was going to blow the tank.. i actually called the local IR dealer.. they thought i was crazy saying that it was still building pressure with the safety valves all flowing. i actually added some tees and 2 more ..

inspect the tightness of the compressor pulley/flywheel on the shaft..

have a look at the motor spec plate.. make sure it has a current and voltage that your location can handle without issues... 120 V 15 or 20 Amps.. 240 volts .. there are things like 3 phase 208 and other odd voltages these use the X Y Z wiring phases that will cause you serious headaches in home situations. power companies don't supply that to homes. there are ways to do it with electronic boxes off 240... my former boss purchased a 5 horse IR compressor that needed 3 phase 208.. we were lucky.. it was already installed in our building.. a former HUGHES tool and die building.
 
#7 ·
Well you were right Wayne. Small compressor. I had some confusion with the guy selling. He thought I was asking about another (bigger) compressor he had for sale. I thought the compressor looked small in the pic, but the guy said on the phone, "it will run die grinders and DA's no problem." Unfortunately the bigger compressor comes with a bigger price. More then I can afford.

Thanks for sharing some wisdom. Now I at least have a clue what to look for with a used compressor.
 
#9 ·
So I found another Saylor Beall compressor. This time its a little bigger. It is a model 703 sitting on an upright 120 gallon tank. The motor is 110v. So I assume 15amp/2 hp?

Do you think this set up would make decent air?

And do you think this set up is worth $300 ?

Thanks guys
 

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#10 ·
While studying up on compressors and safety, I found this video of a gentleman next to a compressor when it blew up. The man survived, but pretty fricken scary.

https://www.youtube.com/watch?v=KVP_A7eGYxw

I think I will be taking tank inspection pretty seriously.

The maintenance department at my work has several pressure vessels inspected and certified on a regular basis. I think I will look into having this done if I buy an old tank. Does anyone know what it takes/costs to have this done?
 
#11 ·
commercial compressor suppliers can do hydro testing on many tanks.. you do need to remove the pump , motor and controls..

its really hard to tell by just looking at a picture if the compressor is any good.. somebody is getting rid of it for a reason. .

in the video.. i would like you to look at the pictures closely at the end..

somebody had been welding on that tank.. you can see the discolorations on one end.. probably used a torch.. the tank weld quality sucked.. there looked like there was improper penetration. and to increase volume.. i would bet the pressure switch was adjusted to the highest pressure before the safety release valves popped open..


how much volume do you need.. how many CFM at what pressure is listed on that tank.. it still looks like a single cylinder but it could be a twin..

there will be a plate welded to the tank.. got a picture of it.. where you can read whats stamped in..
 
#12 ·
It is a twin piston pump. I probably only need 6-8 cfm for most stuff, but it would be nice to use more air tools then electric stuff.

I do have a crappy pic of tank plate. What I can read says:
Nat'l. **** Mfg's. No. 33660
Engineering Controls Div.
St. Louis ShipBldg.- Federal Barge, Inc
H.P. 200 PSI 650
Sh.Thk .2187 Ho. Thk .15**
*0.RAD. 2.1 Year 1***
Part No. 4240
CRN

There is a bit of info that got cut off on the right side of tag. (*=unknown)

its really hard to tell by just looking at a picture if the compressor is any good.. somebody is getting rid of it for a reason.
All I know is the compressor belongs to a local auto repair shop. Mostly running impact wrenches and the like. The owner says they upgraded and this has been sitting for the last 6 months.
 
#13 · (Edited)
Vertical Air Compressors, industrial two stage electric

probably the words buy it.. might come up in a conversation between us.. i still cannot tell how old it is. but the brand new ones look just like it..

you may want to pull the drain out the bottom of the tank and if nothing comes out.. i would fish with a wire up into the bottom.. somebody gave me their old 80 gallon tank.. it had probably 70 gallons of water in it.. took 5 of us to tilt it into the back of my van.. it went when i found out how much water had been in it and sitting for a decade like that unused.. straight to the scrap yard.. the water was really rusty..

hindsight.. i should have left it full of water.. i would have gotten a bucket load of money for it.. might have to start corking pipes after filling them with water or sand before they go to the scrap yard.. i used to see the guys selling cans pouring a little dirt into them before smashing them.. now i understand.
 
#15 ·
mount it to a pallet.. or bolt it to 4x4 or 4x6s.. so it does not tip over.. if you are crazy smart.. you will bore a hole thru the sides of the 4x4s or 4x6s so you can stick an axle with wheels on it.. to allow you to roll it..

if you use 6 .. 4 in a tick tack toe pattern and two outside those. you could mount casters to the bottom of those.. use lag bolts thru them and roll it around to get it home without tilting it over.

or.. carefully dismantle the pump and motor from the mounting bracket.

had a friend move his.. tipped over and broke a cylinder jug right off it.

if you are going to lift it.. look between the compressor mounting bracket and the sides of the top of the tank to see if there is room to slide rebar or bar stock in to hook slings or chains around .. again with extreme care so you don't bend the intercooler.. the belt guard or the flywheel and crank..

i don't know where you are but U haul rents very low garden tractor trailers that with wheels and luck you might get that thing rolled up on and ratcheting strapped down to the trailer in a standing position.
 
#16 ·
Well I walked away from this deal. The compressor looked like it had definitely been taken care of, up until the moment someone dropped it. It hit hard enough that it broke the heavy pulley on all 3 legs. I was worried that more then just the pulley could be screwed up, like the crankshaft, or... The compressor was from 1968.

The guy claimed that it would work fine, and not fly apart, right away. Haha! So I asked him to power it up and show me, but he chickened out. Then he claimed that it could be welded. Being cast iron and all, I don't think I would trust it, regardless of who welded it..
 

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#18 ·
at least it broke before you bought it. at the point it broke.. it became a 100 buck deal.. as the tank is still good... and crank and flywheel are probably still available. but i would want to check the crankcase for cracks where the crank was thrust thru the crankcase..

there are compressor pumps available at harbor freight..

Air Compressor Pumps at Harbor Freight Tools

fairly disposable.

its xmas time.. displays are changing.. you might check at your local home store to see if they are going to be selling off the display models. or if they have any returns. .

the piston and cylinder might be nice Ebay items you can sell off the toppled compressor.
 
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