Inside of a compressor tank - OK to use?

[WhoWhatNow]

Need a little help determining if this compressor tank is OK to use. This is the tank from my Quincy 325 I bought earlier this year. Just getting around to setting it up. The unit was built/sold by Scales Compressor in 1991 so it is relatively young for an industrial compressor. I pulled the plug from the end of the tank and snapped a few pictures. The bit that concerns me is the drain plug at the bottom. Does this look like surface rust or was this tank neglected? What is the deal with the plug at the bottom of the tank. It looks like it is capped. Are there holes along the side of the “cap” to allow air/water to escape? Any help would be appreciated! I have never seen inside an air tank before. Sorry for the crappy pics. These were the best I could get with my phone.

Thanks!

The tank:

By whowhatnow1 at 2011-12-28



Looking up at the drain plug from under the tank:

By whowhatnow1 at 2011-12-28

By whowhatnow1 at 2011-12-28

The drain plug from inside the tank:

By whowhatnow1 at 2011-12-28

Threads on the side of the tank:

By whowhatnow1 at 2011-12-28

Inside the Tank:

By whowhatnow1 at 2011-12-28

By whowhatnow1 at 2011-12-28


Plug from the side of the tank:

By whowhatnow1 at 2011-12-28

 

[Provincial]

It doesn't look too bad. Chase the threads for the drain plug hole with the proper pipe tap. Don't make the threads bigger, just clean the rust off the end of the threads. A new reducer bushing should seat where the old one did, so you are just making sure that the new bushing doesn't bind up on the rust if it happens to seat deeper than the old one.

From the photos the inside of the thank doesn't look bad at all. Every compressor tank that old will have some rust, since the manufacturers don't protect the inside with paint or even an etch. The tanks are pretty thick to meet code. The only way to know for sure is to have the tank pressure tested. They fill the tank with water (so it won't explode if it bursts) at several times the working pressure. I have seen 40 year old tanks pass a pressure test. Your local compresser sales/service company should set you up with a test. Since you have the tank bare and mobile, it will save you quite a bit of money to take it to the shop for testing, rather than have them come get it. Be sure to point that out when you get a price quote.

 

[pro machine Engineering]

All tanks have some surface rust inside them from moisture. Picture 2 to the left looks like a hole rusted thru in the tank. With the pics its hard to tell its a discission you will have to make. a 21 year old industrial tank is a lot of years if neglected. If you dont know the history of the tank and have enough doubt to post asking I would say ditch it. Make a bbq out of it be a lot safer than blowing up the tank

 

[Professur]

I only ever have one answer when it comes to this question. When in doubt, have it hydroed. Having it checked is too cheap to even consider any other option. The guy that fills my CO2 tanks also does extinguishers and has his own hydro setup and gets all my business and recommendations.

 

[gmein]

Certainly have it hydro tested, your local compressor shop or gas bottler can do it for you, do not sand blast or paint, it is best for the person doing the test to do a visual and it be known of any potentials before pressuring up. Plus you wont be wasting any of your time and money on R&R. Air, steam and pressure inside of vessels and delivery systems are of utmost importance to be maintained, my brother has been in the power plant/steam business for almost forty years, I have heard all of the horror stories, the good stories are told because of attention to detail and maintenance safety. Be careful when you do your pipes, never use PVC pipes. Good luck and chime back with your results.

 

[thooks]

Good thread for those of use who have 20-year old 15 amp, 30-gallon compressors sitting around that see occasional use.