Urumqi - Guangzhou

Hi

I am a UK citizen and have an upcoming flight from Ashgabat, Turkmenistan stopping for 5 hours in Urumqi and approx 7 hours in Guangzhou on my way to Auckland, New Zealand.

Please can you advise if any, what Visa I need to complete my journey as I have seen mixed threads about 2 hour limits in Urumqi.
Many thanks
Mark