Quarter turn connection for plastic tubes — Design idea request

I'm developing a 3d project using AutoCAD 2013 and I would like to request ideas for a specific problem. It is not for a commercial project.
It is about how to connect two hollow plastic pipes using a "quarter turn" design.
The only thing that'll run inside them is non-pressurized water.
Is there a way to implement a locking mechanism inside the thickness of the pipes?
All measurements are available next to the picture, in millimeters.
The goal would be to:

-- Connect them without using any tools
-- Be easy to connect and disconnect
-- Have no water leakage outside of the pipes
-- Have a clean design (nothing hanging from the inside or from the outside)
-- Have the locking mechanism implemented inside the thickness of the pipes, at their extremities, 10mm max width, no plastic doohickey on the outside to lock or unlock
I keep trying to find a way to implement the following design but i'm just not visualizing in my mind how the mechanism would work.
http://www.emka.com/in_en/quarter-tu...-quarter-turn/
-- Picture:

http://forums.augi.com/attachment.ph...id=99658&stc=1

Interesting, but so many questions to be asked and answered.

What type of plastic? How hard? How stiff?
If this is a non-comercial project - what kind of tooling will be available?
Will the pipes be horizontal or vertical or at random angles? And how will they be supported?
What temperature range?
Will there be in-service torsion (to act against the latches)?

Why "quarter-turn"? Or is that just a generic use of the term?
1/30 turn gives approx 26 mm of movement at the the outer wall.
If you go for, for example, 1/30 turn, would you want 30 latches? Or 15 perhaps.
Could you use a ring insert (matching pipe id and od) so that both ends of every pipe could be the same?

Ho