Flipping a kayak is part of training people receive when learning to maneuver a kayak wherever they are going. The idea is to purposely upside down the kayak, while still in it and to learn to use another kayak to right size it, get back in it and continue your journey.
I apologize if you wanted to learn how to do this as I never had that training. I do know how to flip a hamburger, flip a coin, flip a mattress, flip my lid, flip a pancake, flip an egg, flip a house, and have heard that there is a drinking game called flipping a cup, I have heard that you can flip someone the bird, flip out, flip a boat (that's what you wanted to know in the first place?), flip the channel (we used to do that a lot before remote control), flip your wig, flip the seat on the toilet, flip around to look, and flip the switch. I guess that's enough flip talk. I better flip myself right out of here.