Compressor help

Discussion in 'Foundry tools and flasks' started by Zapins, May 16, 2018.

  1. oldironfarmer

    oldironfarmer Silver Banner Member

    That's a real two stage. The external line wrapping around the back of the pump is the interstage line. On mine it was finned. Then the discharge line wraps around the front from the cast iron cooler to the top of the tank.

    I've had limited success with the automatic blowdown valves. After several months they seem to get stuck and the solenoid can't open them, just buzzes and it is hard to tell they aren't working.
     
  2. I went back to the video and had a second look and I see that pipe linking one cylinder to the next: is the second stage a much smaller cylinder?.
     
  3. Zapins

    Zapins Silver

    I'm thinking it is smaller. I'll have a look on Friday when I go get it.

    I'll check for that auto valve.
     
  4. Jason

    Jason Silver Banner Member

    I think one is bigger than the other. Don't they re-pressurize the already pressurized air?

    We had one of those auto dump drain valves once in a shop. It used to make me jump every time it went off. Tossed it in the trash. The solution was a proper 1/4 turn ball valve on the bottom instead of the typical POS pitcock that comes on these. Same for the oil drain setup. Plumbed in an extension pipe away from the tank and now I don't mind changing the oil on my pump. Before it made a royal mess. If maintenance is easy to perform, you won't mind the 20 seconds it takes to do it.;)
     
  5. crazybillybob

    crazybillybob Silver Banner Member

    Yes,
    On a two stage pump the first stage compresses the fluid then feeds it to the second stage where the pressure is increased more before it's sent off to the system or the holding tank.
    Vacuum pumps, hydro pumps, air compressors, turbos all kinds of 2 stage systems use this theory.
    In an air compressor system the larger first stage feds the smaller second stage to increase the pressure more quickly.
    CBB
     
  6. Zapins

    Zapins Silver

    oldironfarmer likes this.
  7. Jason

    Jason Silver Banner Member

    They are easier to move if you pull the pump off the tank. :rolleyes: That's the only way I can move my 60gallon. Be damn sure that oil isn't up in the top end of that thing when you start it. I'd stand it up, check the oil level, then drain it for a WEEK before firing it up.
     
  8. Zapins

    Zapins Silver

    What you mean drain it? The oil or the air?
     
  9. I think Jason means the oil in the pump, looking at your photo the plastic filler/breather (thing with red dot on the compressor crank case in the photo) is close to the lowest point, it's a wonder you didn't get oil all over the car interior. They aren't like wet fridge compressors, if it's back upright, the oil level is normal and you can spin the pulley by hand to check for oil/water in the bore causing hydraulic lock (not really possible but you never know) you should be good to power it up. My two cylinder single stage uses straight 46 weight hydraulic oil, I'd imagine yours is something similar. Compressors typically use non detergent oil so that any crap sinks to the bottom of the sump.
     
  10. Jason

    Jason Silver Banner Member

    Thanks mark. I would have hated to see his oil migrate up into the top of the pistons and blow the heads off it. Cool to see, but not when it's your new toy. Yeah if he can spin her by hand, she should be good to go. How it didn't piss all over his car is beyond me, maybe it was M/T already.
     
  11. Zapins

    Zapins Silver

    We taped the oil holes shut and ziptied them so it wouldn't spill. So when I start it up I need to spin it by hand? Should I drain and replace the oil or maybe something else?

    I don't know if I can open the piston chambers up and check for trapped oil. I don't think I can.

    He said he uses husky compressor oil for it.

    Also when I was unloading it i broke the plastic cover that hoards all the wires to the motor under it. Any idea where I can buy a replacement?
     
  12. Jason

    Jason Silver Banner Member

    No you can't open the cylinders. No need to. If you can spin it over by hand, you're good to go. When my compressor was new, I used regular oil for break in. After 10hrs or so, I switched to mobile 1 synthetic. Your call. If you don't know when it was last changed, run it for 10 mins to get the oil hot and change it. Just like a car. That plastic cover MIGHT be available, but they usually come with the pressure shutoff switch. Can you JB weld it back together?
     
  13. oldironfarmer

    oldironfarmer Silver Banner Member

    I'm suitably impressed.:eek:
     
  14. Things like refrigerators have a hermetically sealed compressor bathed in oil and if they are laid on their side the oil can get into the tubes running throughout the fridge, so it's normal to sit it for a day or so upright to get the oil back where it should be. You've had your compressor laid sideways so as Jason suggested, the oil can touch the underside of the pistons and maybe get past the splits in the various piston rings into the bores. Turning it over by hand will soon determine if there's enough oil to cause a hydraulic lock and good idea as it's been laid over.

    It can't hurt to get some new oil and remove some of the particles disturbed from laying it over, if the stuff at the tool shop has some spec like AWS46 then it's straight hydraulic oil with an antiwear additive (about SAE15 approximately).

    As far as the plastic cover is concerned, they are crap plastic in the first place so some decent sheet plastic and some gobs of black silicone would let you work up a repair or failing that even graft on a decent ABS plastic electrical box by cutting a hole in the base of the box and attaching it over the capacitors and terminals, no rewiring necessary. I've had to do this for three 3Hp single phase motors I bought with boxes made out of something with the strength of toffee.
     
  15. Zapins

    Zapins Silver

    Hmm I suppose I can try glue it.

    Wiring it for use. It was originally direct wired into it's own circuit. Is there any benefit to direct wiring it or can I hook it to a 30 amp plug instead?
     
  16. Jason

    Jason Silver Banner Member

    plug is fine. go with what's easiest. I do plugs in my garage. I installed (2) 220 outlets. So I have to play swap the plug with the welder and kiln. My compressor has it's own outlet. Good thing I can run the kiln and compressor at the same time.
     
  17. Peedee

    Peedee Silver

    My whole house is 240V, one of the few things I love about the UK, all my sockets are fed from a 32A breaker through a ring, I can pull 3kw on a single point, more from a c-form. The downside, weather, rugby team, some ginger bloke getting hitched..... Hope the compressor serves you well.
     
  18. oldironfarmer

    oldironfarmer Silver Banner Member

    I sure like the 50a plugs. They will work on a 30a breaker though not technically correct.

    I know a guy who could cast you a nice cover to fit your terminal box...
     
  19. Petee716

    Petee716 Silver Banner Member

    I'd put a plug on it. It keeps your options open. I'm not sure if you need to re-cord it too, but if you do I'd decide how long it needs to be and then add a couple of feet. Again, keep your options open.
    Depending on the size of your workspace's electrical service sometimes it will be prudent to turn the power off to the compressor so it doesn't kick on while you're welding, etc. I consider unplugging to be the easiest, surest way to do that. Otherwise folks end up regularly using the breaker as a switch which is do-able but not recommended.
    If you decide to hard wire it anyway I'd mount a knife switch in-line for an easy, sure power off. But that's just more money.

    Pete
     
  20. Peedee

    Peedee Silver

    I agree with Petee, don't use breakers as switches!

    Oh, as a side note the ginger bloke did get wed! (apparantly)
     

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