Gushing beer from King Keg

[malcolmwinterbottom]

I brew malted extract kits and store the beer in a bottom tap King Keg at room temperature.
All the beer from my last two brews has been lost whlist decanting into a glass when the barrel was approximately half full with the beer gushing onto the floor. The beer continued to gush even when I closed the standard black tap and did not stop flowing until the level fell below the tap. Would this indicate a faulty tap ?
When decanted the beer was mostly foam and the pressure in the barrel at the time was between 5 and 6 psi. I inject CO2 via an S30 valve.
Would fitting a schraeder type valve to the cap in order to release the pressure help ?
I am reluctant to start another brew until I can find a solution to the problem.
Any advice would be greatly appreciated.

 

[Obadiah Boondoggle]

A couple of issues here (at least)

If you fill your keg with water, does it still gush out? If not, it is a pressure issue

Not sure what you mean by gushing

Is the beer at the same temperature as when you carbonated it? The colder it is, the more CO2 it will absorb. If it warms up again (ambient temp is rising at this time of year) will cause CO2 to come out of absorption and create foam. If so, yes you do need a mechanism to release pressure