There are two sides of the gasket. One is flat the over has a valley type of look. Which end goes first. The flat down or up. I’m thinking flat up like the last one but that’s how I had a leak in the beginning
The flat side should face outwards (towards the inside of the tank, exposed to chemical when installed). The side with the 'valley' shape will be installed inwards / facing the handle (and will not be exposed to chemical in the tank).
