How to test a pin lock keg without CO2?

Hello all,

So I've finally convinced SWMBO that I should start kegging -- she's sick of bottling in the kitchen (my plan worked, muahaha) -- and now I'm on the hunt for kegs and kit. Like everyone, I'm trying to save a bit of cash on the process, and I've found a guy about an hour away selling pin lock kegs "as is" for $30/each. He said he "assumes they're clean," and they were "bought for beer a few years ago but not used, and have lived in the shed since then." The photos make them look pretty dusty, but in no worse shape than any other used corny.

He lists the size as "18L," which seems a bit odd: aren't most cornies 5 gallons, or 19L? Common sense says it's a typo/misunderstanding as I've never heard of a 4.75 gallon keg, but I thought I'd check; after all, in the photos there are obviously two different sizes: one slightly fatter and shorter, the other taller and skinnier. My first thought was ball vs. pin lock, but he says all of them are pin lock. Now I'm confused.

I'd like to make sure I'm not buying a bunch of cruddy kegs, but I don't have any CO2 yet to take along for the ride to pressure test. Does anyone have any advice on "quality checking" these kegs without access to pressurization?

Additionally, I obviously want to make sure these are vented before I open one up; can I depress the poppet on the gas in connector with a screwdriver/car key/etc to make sure there's no pressure in the keg before I pop the lid?

Anything else I should be looking for?

Thanks for your advice, everyone!

do they have the regular pressure release valves found in the middle of most kegs? if not then maybe the pushing of the connector would work, just be careful not to damage it..

i don't know of any way except to use co2 to pressure check.. you could use that as an excuse to get a tank and regulator first and take that along for the ride though

Most Coke kegs don't have a pressure relief valve, they only have blow-out valve (it lets go when the PSI become too great).

Yes, you can release the pressure with a key or screwdriver. Let it vent out until there's no more hissing, lift the bail on the lid until it's loose, and push down on it. If it's been sitting for a while, you may need to tap it down with your hand of the blunt end of the screwdriver, or even the blunt end of a hammer. Don't overdo it.

You could use bicycle pump or any other source of air/gas to check that it holds pressure, but you'd need to rig a fitting somehow.

But if you get there and there's pressure in them... that very likely means that they are working fine.

MC

Or if you wanted to be really low tech (but smart)...

Drop one cup of vinegar in the bottom of the keg, and add a couple tablespoons of baking soda, and close the lid, and see if it builds us pressure or if it hisses.

If you go that route, make sure to vent, drain and clean them shortly after.

MC

Misplaced_Canuck said:

Or if you wanted to be really low tech (but smart)...

Drop one cup of vinegar in the bottom of the keg, and add a couple tablespoons of baking soda, and close the lid, and see if it builds us pressure or if it hisses.

If you go that route, make sure to vent, drain and clean them shortly after.

MC

Click to expand...

Ooo, now that is clever! Any thoughts on just how long to wait before I push the poppet to check for pressure?

Yeah, never heard of 18 liter kegs, but if they look like cornies I'd assume they're 5 gal. I also agree with you, the two sizes sound like one ball and one pin. I've seen places that have turned pin-lock kegs into ball locks with new connectors, maybe this one is the other way around? It will be easy to tell once you get there, or have him take a pic of the connectors and see if they've got pins. I've found that hot water and oxiclean give off a little bit of gas when shaken up well, at least enough to hear a small pssh. You could also go with dry ice or vinegar/baking soda, just be sure to either vent it fairly quickly or know how much you're putting in so you don't overdo it. Also, I've found that the cheap delivery chopsticks work great for depressing poppits, figure wood is a little less likely to screw up the metal.

Edit- Ha, beat me to it! Shouldn't have wandered off.

Geordan said:

Ooo, now that is clever! Any thoughts on just how long to wait before I push the poppet to check for pressure?

Click to expand...

I say, shake the keg for 30-60 seconds and see what you get. I'm sure other more chemically inclined homebrewer will chime in.

MC

This is all excellent advice, thanks guys. MC, you said to wash the kegs out pretty soon after the baking soda trick; does anyone see an issue with them sitting in the car for approximately 2-3 hours before I rinse them out? They are, after all, stainless steel -- I can't imagine they could be THAT damaged in a few hours, right?

I suppose the acid could start to do some bad things. If you're really worried about it, add a gallon or two of water to them to dilute out the acid, and you should be fine.