Compressor check valve - repair?

[skelrad]

I'm learning as I go...

In-line check valve from an old Speedaire. The spring is busted, but is that it? Is that plastic sleeve/ring supposed to be a separate piece like this? Just trying to figure out if I can repair this valve or if I have to buy a new one. The in-line valves like this are $30+, so if this is salvageable I'd like to try! I can't find a diagram anywhere about how these in-line valves are built - unfortunately I didn't see the thing when it was in one piece, so I don't know how it's supposed to go back together (where the spring and plastic ring come into play).

[URL=http://s913.photobucket.com/user/bryostdc/media/0.jpg.html] [/URL]

 

[firebox40dash5]

Looks just like the one I replaced on my Speedaire. I too tried to fix it, couldn't get it to work, and I think it ended up being like $12 at Grainger.

 

[Grounded Ken]

It is a standard wear item. Some have rebuild kits, most don't. Peace of mind, buy a new one.

 

[skelrad]

Looks just like the one I replaced on my Speedaire. I too tried to fix it, couldn't get it to work, and I think it ended up being like $12 at Grainger.

I figured it would be less than $10, but at Grainger it's $21. Surprised me!

http://www.grainger.com/Grainger/CDI-CONTROL-DEVICES-Check-Valve-4X997?Pid=search

 

[trbomax]

They are only about $12 from surplus center.

 

[sselander]

If you get a new one, you will have to plug the hole that is meant for the unloader valve on the newer pumps. I replaced my aluminum check valve with a brass one and put a pipe plug in the hole.

1/2 thread
http://www.surpluscenter.com/item.asp?item=4-1769&catname=

3/4 thread
http://www.surpluscenter.com/item.asp?item=4-1770&catname=

 

[skelrad]

They are only about $12 from surplus center.

Yeah, I checked there but couldn't find a match unfortunately - I need a 1/2" inlet and 3/8" outlet male/male in-line valve. If I ever redo the routing of the pump lines I'll definitely modify it so I can just use one of the cheaper in-tank check valves.

 

[skelrad]

I got my new check valve installed and it works great! Next question - since it's an old compressor and I haven't taken the thing apart and checked all of the fittings, it does have a slight air leak (at least I hope it's from the fittings). I lose about 2.5 pounds every 10-15 min. Is that normal/acceptable, or should I dig in and start reworking fittings? I have no idea if that's just typical for a compressor or not. I soaped up most of the fittings and found only one itty bitty leak that I fixed. Maybe that was the culprit, but it seemed awfully small to amount to any measurable loss of preasure over 10 min.

What is normal?

 

[trbomax]

normal and acceptible are two different things.Normal on a reciever of that size would be maybe 1 or 2 psi/24 hrs. In my shop5 psi/ 24 hrs is acceptible,but I have 140 gal of reciever capacity.

 

[djjsr]

When my compressor started losing pressure (about 10 psi overnight) and I couldn't find any leaks, I took the regulator apart. Cleaned out some crud, put a little spot of grease where the screw meets the diaphragm and put it back together. It worked.

 

[skelrad]

After testing nearly every fitting and scratching my head trying to find leaks (none that I can find), I'm pretty sure that my mystery "leak" is just due to a funky pressure guage. It's a Harbor Freight special, so it's no surprise that it's not exactly accurate. The pressure regulator and the pressure guage between the pump and tank do not agree, especially at the higher pressures. When the pump shuts off, I automatically lose about 5 lbs of pressure according to the guage, but then I lose nothing over 24 hrs. To me that says that the guage just doesn't register the initial pressure accurately, maybe just because of the vibration from the pump or something. Regardless, I think it's all good.