When pumped concrete is used on a high-rise project, an efficient line cleanout method is needed. By using a hydraulic diversion valve connected to a short section of cleanout line, the concrete left in the line after a pour can be routed directly into a waiting truck.


Vertical lines for high-rise work should almost always be cleaned by moving concrete back toward the pump. In the most common method, a go-devil or blow-out ball is inserted at the discharge end of the slickline and a blow-out cap is attached. Compressed air is then used to push the concrete out of the line.


On many large-volume pumping jobs, a separate cleanout station is used. After the blow-out ball is inserted and the blow-out cap is attached to the end of the slickline on the deck, the diversion valve is switched and concrete is pushed down the riser pipe into an elevated discharge line and out into a ready mix truck. If the cleanout line is very long it may have to be primed with a cement-water slurry.