Frog flap

from Wikipedia, the free encyclopedia
Frog flap by a stream

A frog flap , sealing flap is also a mechanical locking device against the entry of animals at the mouth of water tubes in the open countryside or in outfall . It is used to keep drinking water clean and prevents clogging of the pipe by animal carcasses in drainage and sewage pipes.

use

Frog flaps are found at outlets and overflows of waterworks , water containers or spring taps for drinking water supply . They are intended to prevent the entry of smaller animals (e.g. frogs ), which otherwise migrate into the containers and cause problems with the water quality there. In the case of drainage pipes laid in the ground, they are intended to prevent animals that have penetrated the pipe and perish from clogging the pipe.

functionality

Metal frog flaps are attached to the top of the tube with a hinge and close by their weight. Water flowing in from the inside opens the flap and closes when the stream stops. Some flaps are provided with seals and thus form a simple backflow protection that can prevent dirty water from penetrating the pipe system during floods . For simple purposes there are frog flaps made of rubber, which, thanks to their flexibility, prevent backwater in the event of a counter flow.

Meanwhile there are also frog flaps, which are screwed inside the pipe with the help of clamping screws and can contain special designs (outer ring open at the bottom, opening on one side).

literature

  • Ernst Rodenwaldt, Richard-Ernst Bader: Textbook of hygiene. Springer Verlag, Berlin 1951.
  • Gerhard Merkl: drinking water tank. Oldenbourg Industrieverlag, Munich 2005, ISBN 3-486-63064-4 .

Web links

Individual evidence

  1. ↑ H. Damrath: water supply. Springer-Verlag, 2013. ISBN 978-3-322-94741-3 . Cape. 8.3.1. Pipes, on page 213.
  2. ↑ Healthy drinking water from own wells and springs , Federal Environment Agency, accessed on May 4, 2017
  3. ↑ www.froschklappe.com , accessed on May 4, 2017