Do i need any transit visa to tranfer from China in both airports?

Im a Turkish guy living in Seoul. In the middle of december, planning to go Turkey. I bought my ticket from China Southern Airways. 2 transits to Turkey and 1 transit to Seoul when coming back.
First one is Seoul to Dalian, China | Zhoushuizi International DLC to Beijing, China | Capital International PEK | Terminal 2 and Istanbul
When coming back Istanbul to Beijing and to Seoul.