I was working on making a small dispensing machine for tea for a sort of extra-curricular competition and including a small pumping system for quick discharge of milk and water. I have seen some machines exist before that dispense tea, coffee etc. What small pumps do they use ? It's surely not gravity driven as gravity wouldn't impart that much speed to the flow as a pump would. Any specific name or brand for such kind of pumps so I can search the market out for their availability.