Question: "Is it possible to install your ceiling fans on a pitched ceiling?"
Answer: These ceiling fans are able to be directly mounted to raked / pitched ceilings if the angle is a gentle slope, no greater than a 14-degree pitch.
If a level cross-beam is present, your installer can often mount the ceiling fan to this.
Otherwise, you may need to install a bracket and plate, or a chamfered block, to create the necessary mounting angle base to suit. Something like this: