A300
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution
Aircraft
# 1 Bleed Value MEL inoperative.  Aircraft limited to FL310.  At FL310 we got a #2 Bleed Valve Fault.  As per ECAM tried to reset it.  It would not reset.  Advised Center that we lost the ability to Pressurize and requested a descent to 10;000 ft.  Flew direct to ZZZ at 9;000 feet to an uneventful landing.#2 Bleed fault with no reset.   #1 Bleed Valve MEL inop.  Fix the Bleed Value when it breaks and do not MEL it.
Started descent; First Officer was pilot flying. We got our O2 mask on! I was coordinating with Center; then started on ECAM items. By the time I finished ECAM and got into QRH we were through 19;000 feet. QRH mentioned starting APU. By this time we were close to 10;000 feet and 124 NM from ZZZ. Did not start APU; and proceeded direct to ZZZ at 9;000 feet. Uneventful landing ZZZ.
A300 flight crew reports being dispatched with the number one bleed valve deferred. At FL310 the number two bleed valve faults and cannot be reset; resulting in an emergency descent and diversion to a suitable airport.