I have a 12 hour stop-over in Bejing, can I stay in the Hourly lounge in T3 C without a visa ?

Yes, it's not necessary for you to have a visa because your transfer time is within 24 hours.
Do you mean the restaurants at the airport? If yes, you can access to all of them with no visa. Don't worry. But if you wanna go out the airport and tour around downtown area, you need to apply for a Stay Permit first.