Armstrong Pumps has announced that its popular 4270 motor-mounted centrifugal pumps are now available with either engineered-polymer or cast-bronze impellers-the latter immediately, with standard lead times. This design change applies to both configured 4270 pumps and stock 4270 models. All 4270 pumps provide tapped openings for venting, draining and gauge connections and also feature heavy-duty, permanently lubricated motor bearings.