NA-05 - Cleaning: Cleaning Strategy and Programme

Table of contents

Determination of cleaning intervals

Classification and assessment of deposits

Following the acquisition of deposit data from the individual sections and manholes, the findings are classified and assessed. Below you can see an example of a three-step model for the classification and assessment of data, which has been developed and applied in several research projects.

Class 1    

  Quantity: no to small deposits

(deposit level ca. 0-10% nominal pipe size)

or

  Composition: fine-grained/loose  

Class 2    

  Quantity: small to medium deposits  
(deposit level ca. 10-15% nominal pipe size)
or
    Composition: viscous/low viscosity

Class 3    

                 Quantity: medium to heavy deposits                 
(deposit level > 15% nominal pipe size)
or
Composition: solid/rigid

 

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