Heavy Duty Ball Valve Pumps are recommended for abrasive slurries, suspended and non-suspended solids and line-size solids. All Sandpiper®® Heavy Duty Flap Pumps are configured with bottom discharge porting to prevent settling solids from shortening pump life and provide superior suction lift. Most HDF pumps are thick wall constructed of Sand Casted Aluminum, Cast Iron or Stainless Steel with elastomer and TPE (thermal plastic elastomer) diaphragms and check valves. See Individual pump descriptions for more detail.