Powers, Duration of Effect
All powers of attorney created in Pennsylvania are also presumed to be durable powers of attorney.  Powers of attorney also do not expire with time and, if properly executed, will retain their validity indefinitely.

The agent has the authority to exercise every power listed in a power of attorney until that document has been revoked or until the principal's death.

See: Powers, Scope; Power of Attorney, Revoking; Power of Attorney, Delivery