EXT writes:

Also the CO2 gas supply for drinks should not be industrial grade
possibly with oil and other contaminants, the gas should be identified
for drink dispensers and be oil free.

This is a myth.

"Industrial" grades are actually *cleaner* than beverage grade. Welding
processes cannot tolerate contamination.

CO2 tanks deliver vapor over liquid, which purifies further by distillation
and purging.