The parts of the valve. You can see the two bigger rings: they are located INSIDE the big T-tube.

The FLAT side of the big sealrings point to OUTSIDE left and right. All plastic-parts have notches, look for them when reassembling these parts.

The white fresh water hose has a metal spring-claw, too and can also pulled away if consisted.

When reassembling use a little bit of food-silicone-grease on every sealring.