Well I will only install a new genuine cap at 0.8 bar stamped on the cap.
Which is about 11.5 psi.
You can get a decent cap as a stop gap from a parts store which is rated at 12psi.
Stant makes a good one but in most cases off the shelf it will be a 14 pounder if you are a walk in customer.
I have used the "14 cap" with success as a stop gap but always change it for the real deal from the dealer.
The cap of course maintains the boil margin.
Dennis