French to English Tech/Engineering Construction / Civil Engineering fountain engineering

Hi!

This term is in the Filtration section of a fountain engineering contract under the heading "DISTRIBUTION OF THE TRIBUTARY AND COLLECTION OF THE WASH WATER"

This is the french:

L’arrangement du système de distribution doit être en forme de H et permettre un lavage efficace des lits filtrants sans perte de milieu filtrant. Les extrémités doivent être pourvues de coudes ouverts vers le haut pour éviter toute perte de média. La distance entre la surface du lit filtrant et des goulottes de collecte d’eau de lavage ne doit pas être inférieure à 50 % de l’épaisseur du lit filtrant.

This is my tentative translation:

The arrangement of the distribution system must be H-shaped and permit an efficient washing of the filter beds without the loss of filter medium. The ends must be fitted with large radius elbows (wide bends) towards the top to avoid any loss of media. The distance between the surface of the filter bed and the wash water collection discharge spouts must not be less than 50% of the thickness of the filter bed.

Thanks for any suggestions!