Syphon/Depth to insert Flush pipe

[Nitell]

I bought a Macdee Elan Exposed Cistern with flush pipe.
I believe the flush pipe should be pushed to the top of the Syphon. Am I correct?.
It seems somewhat tight.
Thank you.

 

[Elkato531]

The flush pipe needs to be inserted far enough so that a good seal can be made. The length of the threads on the bottom of the siphon is about right. A couple of inches or thereabouts.

 

[Madrab]

With most syphons/flush valves there's usually an internal stop for the pipe, a little peg of plastic sticking out into the outlet.

 

[Nitell]

Ok.
When I inserted a ruler, it went in as far as approximately 290mm.