SBX Master™ Barrel Retrofits Home › Customer services › Upgrades › SBX Master™ Barrel RetrofitsAn upgrade is available for Baker Perkins’ SBX Master™ extruders that reduces the cost of replacing worn barrel liners. The upgrade entails fitting a new barrel assembly comprising a one-piece backing block with liner segments that can be independently removed and replaced.This is a straightforward maintenance operation enabling a barrel to be renewed simply by changing the worn liner segments, rather than replacing the whole barrel. The reduction in cost and downtime is up to 50%.The upgrade includes improved heaters and a choice of liner materials, depending on application. It is available for MPF50, MPF65, MPF80, MPF100 and MPF125 twin-screw extruders for extruded cereals, snacks and other foods.Scope of workThe parts supplied are a complete new clamshell barrel assembly comprising top and bottom backing blocks fitted with slab heaters and replaceable liner segments. The new barrel assembly is fitted to the existing frame and laser-levelled. Modifications to the frame are not normally required.The initial installation must be carried out by specialist Baker Perkins engineers. Subsequent liner changes may be undertaken in-house.The liner segments are precision-machined to high tolerances for easy removal and replacement. When installing new liners no adjustments to the backing block or segments are necessary.Slab heaters are fitted instead of cartridge heaters. They provide more uniform heat distribution, offer longer life and are easier to replace Technical Bulletin: Barrel Retrofits for Food Extruders