What was found
AT CRUISE ALTITUDE OF 37,000 FEET RECEIVED A CAB PR SYS 1 FAULT. MOMENTS LATER RECEIVED CAB PR 1 & 2 FAULT. REQUESTED IMMEDIATE DESCENT WITH ATC. CABIN PRESSURE WAS HOLDING STEADY AT 7,000 FEET. REPORTED TO ATC THAT CABIN PRESSURE WAS HOLDING AND RECEIVED CLEARANCE TO LEVEL AT 19,000 FEET. NO EMERGENCY WAS DECLARED, CABIN O2 MASKS DID NOT DEPLOY. UNEVENTFUL LANDING. REMOVED AND REPLACED OUTFLOW VALVE 32-2130-9-0009, S/N OFF 91680.