72-Hr Free transit

My family is traveling to Manila. We are american citizens and our flight is from RDU to SFO to BEIJING to Manila, with the layover in Beijing for the 2 hour.
The return will retrace the route, so MNL-BEIJING-SFO-RDU.

This free-72-hr applies to my family, and we don't need a visa?

Thanks.
DeAgners.