Let's go through our keg and the little parts and pieces that are associated with it. 

On top of the keg is the relief valve. It just pulls straight up (to release the pressure from the keg). These are easily removed by simply screwing them out. You may need to replace the little O-Ring from time to time. 

Next is the keg lid, now these are on corny kegs not your commercial kegs (they are different) 

When you lift up your lid you should see an O-Ring under there, this is important for it to seal properly. There are also little feet, the feet are on there to create downward pressure to lock the lid into place.

We then have our two posts. 

A gas post on one side and a  liquid post on the other side.  How do you tell the difference? Gas posts have notches, liquid posts don’t. 

The part which sits under the posts is called a poppet valve. The poppet valve goes into your posts and screws on to the posts that go down into the keg. The liquid post has a long tube going down into the keg to bring your beer up from the bottom,and the gas one is nice and short (just enough to push your gas into the keg). 

These do leak from time to time. It's simply a matter of unscrewing it removing the poppet valve, and changing the O-Ring  (or the whole poppet valve - they only cost a couple of bucks). Set that back in and re-screw it, hook it up and test it for leaks. 

The other important piece is the disconnects. There are two:

Black for beer and grey for gas (very important). Don't get these mixed up! 

If you do you won’t get them off the post and you will damage both the post and the disconnect.  

Disconnects connect to the all important beer and gas lines. These ones simply clip on. 

Beer is out, gas is in and that is your disconnects.

If you're having trouble getting on your  disconnects just use a  bit of lubricant or some spray on sanitizer will do the job to loosen that up. 

From time to time every 12 months or so you will find you'll have to replace the little black O-Ring on the gas post, that helps to keep it all nice and sealed. 

Disconnects also available in stainless steel - both barbed and what's known as an MFL fitting. 

The MFL fitting is a one screw, you simply screw a pushfit on and connect your lines. You don't need to over tighten these (people often do - this damages them, so be careful).

Make sure you've got a nice clean cut on your line.Then, push it in. Give it a tug if it won't come out then we know it is on there nice and tight. 

To retract it we simply push the edge of it in then pull the line out at same time. Makes it really simple and easy to use if you need to move your kegs or have to do any maintenance. 

If you don't want to use push fits, you can go to a crimp on a barbed disconnectl.To connect your line, simply heat it in some hot water stretching it out with a set of long nose pliers, pushing the line in over the barb.

Get a set of pinches on the stepless clamps. I prefer to use stepless clamps because the inside diameter of the stepless clamp goes over the whole line. Thus closing it really neat and tightly and you don't get a flat spot as you would if you used a screw. 

If you squeeze it  together you will be able to see that the hole in the circle has gone around that line nice and tight.

That’s it. These are the key parts and connections for your  homebrew corny kegs.