The Hawle valve surface box for rolling in is to be used for installation in bituminous traffic areas. The drawing ring permits a large adjusting range.
Prior to rolling in, the drawing ring shall be pulled upward approx. 1-2 cm above the level of the asphalt covering and backfilled with asphalt. During rolling in a bond is created between the drawing ring and the asphalt. Thus the traffic load is discharged into the base course. Due to this bond the surface box and the road covering remain at the same level.
Compared to conventional surface boxes the angle seat at the cover and the box provides for reduced rattling of the cover.
To avoid contact corrosion between the cover and the box, on the one hand, and to ensure that the cover comes loose easily, on the other hand, the latter is powder-coated.