Pressure relief valve question

At what pressure does the pressure relief valve on a keg give ?
In other words if one had to accidentally prime with too much sugar ?

the pressure relief valve is there for YOU to release excess pressure. It shouldn't open by itself until it is likely 1.25-1.5x the pressure rating for the keg of 130psi or so.

I thought it has dual purpose - thanks.
Will it definitely give or is there a risk of the keg exploding / bulging ?

There is no way you could overcarb it so much to explode the keg. The maximum you could ever overcarb the beer is if you accidentally left it on 30psi. And that is still 1/4 of the maximum pressure.

You may just have to relieve pressure a few times over the course of a day or two in order to get the beer to a more reasonable CO2 level.

If you found you've overcarbed. Keep the beer in the fridge. Release the co2. Let it stabilize for 8 hours or so, take a sample. If its still over carbed repeat the same process until it is at a desirable level.

I was thinking of overcarbing as a result of adding too much sugar by mistake. You know....after a few too many homebrews etc. I havn't done this - just pondering.
I recently used two carbonating drops in a 750ml bottle. Now while this is normal procedure I forgot that the beer in the bottle was at 2C - bottle needless to say the bottle exploded. I blame the homebrew

Bru,
You don't have anything to worry about. If the relief valve opens you may have a bit of mess on your hands but it will close once pressures get below the rating. You would have to add a lot of sugar to get any where near those levels though.

Bru said:

I thought it has dual purpose - thanks.
Will it definitely give or is there a risk of the keg exploding / bulging ?

Click to expand...

It does. You are right the main reason would be safety. The secondary reason is to let the pressure off so you can open the lid.

We homebrewers use it as way to regulate the carbonation and pressure but in the cornie's former life as a soft drink container that really wasn't a consideration. Because the soft drink distrubtor / bottler set the cornies and CO2 up for a pretty much turn key operation..

Actually the keg's conservative rated pressure is 130psi. The pressure relief will open at about 70psi. Some keg lids have NO relief at all, some have over-pressure valves that cannot be manually pulled, while many have the combo overpressure/manual dumps.

I don't worry too much about the kegs of mine that have no relief. I don't sugar prime the kegs so if I have a malfunction with my regulator and the pressure hits over 100 psi, I'm sure it will either blow the QD apart or the hose will blow off the barb before the keg explodes.