Here are some early modelling of the valve.
Fig. 1. Top view. Images has been resized. Click to view original image.
Fig. 2. Port view. Images has been resized. Click to view original image.
Fig. 3. Images has been resized. Click to view original image.
Fig. 4. Images has been resized. Click to view original image.
Fig. 4a. Images has been resized. Click to view original image.
Fig. 5. Deck hatch closed. Images has been resized. Click to view original image.
Fig. 5a. Deck hatch open. Images has been resized. Click to view original image.
Fig. 5b. Deck hatch open. Images has been resized. Click to view original image.