I am going to Beijing, Pekin first and then after around 5 hours I will fly to Turkmenistan.

That I will be staying in Beijing airport only for around 5 hours. So do I need to receive visa for this flight through China. But my airplanes are different that is, I will fly with Chinasouthern first then in Beijing, I will change my airplane. So will that cause a problem in transit? Thank you for your help!
Sincerely Perman.