---
title: "Flap Valve"
canonical: "https://help.innovyze.com/space/infodrainage2021v1/16548522/Flap%20Valve"
format: markdown
---
The **Flap Valve** works in the same way as an  [ ](https://help-innovyze.atlassian.net/wiki/spaces/infodrainage2021v1/pages/16548459)**[Orifice](https://help-innovyze.atlassian.net/wiki/spaces/infodrainage2021v1/pages/16548459)**[ ](https://help-innovyze.atlassian.net/wiki/spaces/infodrainage2021v1/pages/16548459)except reverse flow is not allowed.


![image](media://7580d36d-999b-48b9-804c-3deec504d8fb)