... : n 2900/1450/980rpm 3500/1750/1180rpmDescription Horizontal axially split casing, double volute multistage design. Impellers arranged in opposed groups, KSY ... design for low NPSH required. Removable wear rings protect the casing and impeller. The impellers are statically and dynamically balanced. The ... API 610 Eighth Edition, August,1995. Heavy Duty Axially Split Casing Multistage Centrifugal Pump