I have a circuit thatg pulls a load of 19 amps what size circuit breaker do I need for protection

Lets try it this way, please.

Are you talking of 120V @ 19 amps or 240 V @ 19 Amp?

What are you using this circuit to power?

Is there anything else on this circuit? Or is it a dedicated circuit between the panelboard and the outlet for the device?