72 hours permit

Hi,
I am thinking to get a roundtrip ticket from LAX to PVG, flying out on 8/29 and back on 9/8/2013. And another roundtrip PVG to HKG, leaving on 9/1 and back to PVG on 9/8, connecting to the LAX flight. Am I eligible for the 72 hours free transit permit?
Thank you