Ultra-low-cost factory direct supply rubber inflatable mandrel rubber inflatable mandrel is an expandable, contraction of the cylindrical bag, used to form a cavity concrete elements, in the manufacture of hollow components, rubber inflatable mandrel into the middle, and filled with compressed air, rubber inflatable mandrel is shrinking, and can be withdrawn from the inflatable core mold cavity. Rubber inflatable mandrel is simple to use, economical and durable, not soft, inflatable can shrink any folded, curled, inflated after sufficient strength to withstand the pressure of concrete, which is unmatched by any of the traditional rigid template. For reinforced concrete pumping holes, including piles, roof trusses, roof columns, beams, construction, hydraulic engineering (dock, boat lift, dock). Construction proved rubber inflatable mandrel pumping holes process equipment is simple, not only to save material, and has the shape changing characteristics, can be as round, oval, rectangular, arched, octagonal, trapezoidal and other pipeline. You can also become straight hole, variable cut faces, etc., can become light building structures, thin-walled hollow, concrete properties has been used to change the status of rigid template.