Problem solver
The problem was that in an existing sewage system, when backflows occurred, water was forced into the manhole inlet. This should be prevented.
Removing and replacing the entire, heavy concrete shaft was not an option.
A FROG PEGK insert flap was used.
In this pdf you can see how an existing inspection shaft can be retrofitted with a FROG insert flap type FROG PEGK in a few minutes without tools.
You can find this article in the price catalog K22 on page 13.
