I will be arriving in PEK on Thai Airways International from Bangkok on the 22/4 at 3:50pm.

If you hold the connecting flight boarding pass, just confirm the boarding gate via the flight display screen, and follow the guiding signs to the corresponding boarding gate.

If not, you need to go to Transfer Counter on 3F to handle transfer procedures: immigration- security check- customs- wait and board.

By the way, both airlines use T3, and the minimum connection time is 60 minutes. Good luck to you! :)