How to seal a conduit with an underground cable?

Good morning,

we want to lay a conduit with underground cable in the garden for 1-2 outdoor sockets. We want to lay the underground cable in the conduit so that it is protected and replaceable.

The conduit would end underground in the open just before the outdoor socket (pillar socket).

How can we properly seal the end so that no water, sand, other dirt, or animals get into the conduit?

Should we foam the end of the conduit with something? If yes, what?

Or should we put a waterproof heat shrink tube over it?

Or is there something else for that?

We only want to put 1 underground cable 3x2.5mm in the conduit, so DN25 should be sufficient, right? Can you recommend a conduit?

With a suitable ring groove seal, you are on the safe side.

I expressed myself a bit incorrectly.

It is about the open end at the outdoor socket.

We get the power from the garage and lay the empty conduit through the already existing floor sleeve.

You can also screw in an external ring seal at the end. At least that would be a solution to your question. I have implemented it exactly like that and for exactly those reasons.

How can we properly seal the end so that no water, sand or other dirt or animals get into the empty conduit??

Oh, ok

is there perhaps a cheaper solution?

Can the conduit be foamed with foam? Just like with other conduits that, for example, go onto the roof for, for example, photovoltaics

The cable in the conduit will 99% probably not be replaced anymore

Unfortunately, I do not know that. For me, sealing was the most sensible solution (among other things, power and LAN to the wallbox). Maybe one would want to add another line later. That is why I also installed 125mm KG pipe - there is enough space and the effort is the same...