What was found
AIRCRAFT WAS GROUNDED: AIR ENGINE 1 BLEED NOT CLOSED ECAM ILLUMINATED AFTER TAKE OFF, BLEED OFF - BLEED VALVE REMAINED OPEN. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO LIM WHERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT. MAINTENANCE REMOVED ENGINE 1 PRESSURE REGULATING VALVE AND FOUND ONE SEAL MIGRATED INTO THE VALVE. RE-INSTALLED THE PRESSURE REGULATING VALVE WITH NEW SEALS PER AMM 36-11-52. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO LEAKS NOTED.