In retention roof drainage, there is an increasing need to be able to adjust the retention discharge through the retention openings on the retention pipe. For this purpose, the new retention rotary valve drain has been developed.

On-site adjustment

The essential feature is that the relationship between retention discharge and retention water height can be securely adjusted using a rotary slide. Unlike retention drains with factory-made retention openings, the number of retention openings is adjusted on site by the installer.

The five rectangular drainage openings of equal size, arranged side by side, enable each opening to independently achieve the same relationship between retention discharge and retention water height. This ensures that each additional opening produces exactly a multiple of the discharge, and that undesirable interaction between discharge capacities and water heights is reliably excluded.

Table for the number of retention openings

The planning specifies the retention discharge (in l/s) and retention water height (in mm) for retention roof drainage as requirements. Based on these two specifications, the number of retention openings can be read from the table.

In the table, first (1.) the row for the specified retention discharge is selected (table left), then (2.) the given water height is selected (table fields), and then (3.) the required number of open retention openings is read above (table top).

Advantages

• On-site adjustment of retention discharge
• Table for the number of open retention discharge openings
• Calculation programme based on measurements
• Stock-keeping possible without project-specific production
• Weather-resistant and durable, made of stainless steel