Craftsman 30/33 gallon compressor

[kythri]

So, my small compressor, a Craftsman (Devilbiss) 30-gallon or 33-gallon upright unit (I'm spacing on what it is at the moment) won't shut off anymore when it gets up to pressure.

I caught it a while back, and I've babysat it now when it's charging, but I'm curious, what part would this be that I'd need/want to replace?

 

[Davefr]

So, my small compressor, a Craftsman (Devilbiss) 30-gallon or 33-gallon upright unit (I'm spacing on what it is at the moment) won't shut off anymore when it gets up to pressure.

I caught it a while back, and I've babysat it now when it's charging, but I'm curious, what part would this be that I'd need/want to replace?

Pressure switch most likely:

http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=3644&PMITEM=54037288&PMCTLG=00

 

[bullfrog123]

I have a similar (horizontal) CF compressor that won't even pressure past 80. Runs and runs forever but won't go past 80. What would cause that??? Pressure switch too?

 

[kythri]

Thanks, Davefr!

Would I be correct in assuming that the lower pressure indicated is the "kick-off" level, and the higher is the "cut-off" level?

 

[Davefr]

I have a similar (horizontal) CF compressor that won't even pressure past 80. Runs and runs forever but won't go past 80. What would cause that??? Pressure switch too?

I doubt it. Most compressors put out more then 80 PSI so it sounds like your unit won't charge the tank so the pressure switch never cuts out.

I'd guess bad valves, bad rings or a major leak (maybe head gasket)

Thanks, Davefr!

Would I be correct in assuming that the lower pressure indicated is the "kick-off" level, and the higher is the "cut-off" level?

Low pressure = cut in, High pressure = cut out

 

[kythri]

Figured I'd resurrect my own thread, since my query is a continuation of the same issue...

I still use my 33-gallon job for various things, and never got around to buying a new pressure switch for it.

Started getting serious about it today, and started looking at the owner's manual, which states cut-out PSI is 150, cut-in PSI is 120. I could have sworn that this thing cut-out a lot earlier than 150 PSI when I first bought it.

Am I correct in assuming that tanks are normally rated lower than true max PSI, so running a max 150 PSI tank up to 150 PSI isn't going to be an issue? I want to test this to see if it actually cuts out at 150, rather than spend money and time on a new pressure switch that may not actually fix what I perceived to be a problem in the first place.

 

[david594]

The tank likely was a stamped plate on it somewhere that states the max pressure the tank is rated for. I own a dewalt compressor and there is a devilbiss plate on the tank that says its pressure rating.

 

[DirtRoad]

Man i must have gotten lucky. I have a 33 gallon 6 peak HP oiless Craftsman upright and have been using the snot out of it for 11 years. I cant seem to kill the damn thing and my wife wont let me get a real compressor until this one dies.

 

[djjsr]

I have the same compressor. It says 150 on the sticker. It shuts off at 140. I thought maybe the gauge was off a little so I put on a new one. It still shuts off at 140.

If you need parts for that thing you might try Master Tool Repair's website. I recently got a checkvalve from them.

 

[kythri]

Well, just decided to let it run and see - sure enough, it cuts out at 150 PSI, cuts-in at about 115-120.

I could have sworn that the cut-out was far lower when I first bought...

Funky.

Guess I don't need to buy a new pressure switch. YAY!

 

[kythri]

Out of curiosity, does anyone know how tank max pressure is rated?

For example, ANSI (I think?) ladder ratings are tested at 4x the listed max capacity.

Not that I will or can run it past the listed rating, but I'm just curious.

 

[DirtRoad]

Mine has always been 150psi cut out and 120psi cut in.

I dont know what the tank is rated for but im willing to bet its alot more than 150psi.

 

[kythri]

Metal tag on the tank says MAWP of 167 PSI at 350 degrees F.

Could have sworn I looked at that tag and it said 150, but must have been looking at the sticker.