Is it allowed to lay KG pipes in gravel?

Hello everyone,

Normally, KG pipes should be embedded in sand underground. What confuses me, however, is that drainage pipes are supposed to be embedded in gravel (e.g. 22/32), even though the drainage pipes appear to be much less stable than KG pipes (e.g. KG-2000).

Why is that?

Best regards

The gravel in a drainage is supposed to direct the water into the pipes.

And the sand around the [KG Rohre] is supposed to protect the pipes from damage caused by stones etc.

Thank you. So far so clear. But, can't the gravel damage the drainage pipe, but a KG pipe can?

Gravel will not damage a [KG pipe] either...

No idea if it’s allowed, but I think the pipes should be able to withstand it.

Why risk a fracture? Is it going to fail because of a few shovels of sand? And what kind of load is to be expected on the topsoil? Sidewalk or [Speditionshof]? I might possibly still live with the sidewalk, but the latter is definitely too risky.