Grundfos UNILIFT AP50 and AP50B pumps handle dirty stormwater, groundwater and suitable non-aggressive wastewater. AP50 models have maximum flows of 416.4-499.8L/min and maximum heads of 9-12m; AP50B models have maximum flows of 400.2-466.8L/min and maximum heads of 11-14m. Maximum flow and maximum head are separate limits. Actual flow depends on lift and pipe resistance; use the matching 50Hz performance curve to assess expected flow.
Both designs have a 50mm (2") Rp / BSP female outlet: vertical on AP50 and horizontal on AP50B. Both pass spherical particles up to 50mm and suit water containing small amounts of suspended solids. Neither design is suitable for stones, long fibres, aggressive or flammable liquids.
Both designs suit collecting pits, dirty stormwater and suitable domestic wastewater. AP50 excludes sewage and toilet discharge under its installation manual. The AP50B manual permits toilet-discharge use only where local regulations allow a 50mm free-passage vortex pump.
All four stocked models include a tethered float switch for automatic start/stop, a 10m cable and an Australian plug. They use 220-240V single-phase, 50Hz power. Internal thermal overload protection resets after cooling; no separate motor-protection control box is needed. Keep each float free to move and set it for the chosen design’s operating requirements.
AP50 has a motor cooling jacket supporting continuous running without scheduled cooling rests while partly submerged, provided the entire inlet strainer remains submerged in the liquid being pumped. Do not run dry.
AP50B requires the motor and pump inlet to remain completely submerged for continuous running. For intermittent pumping with cooling rests, keep at least half the motor submerged and follow the manual limit of maximum 5 minutes running per 30 minutes when the motor is not fully submerged. Set the float stop level to maintain the submergence required for the duty.
Both designs can stand on a firm base clear of sludge and mud. AP50B also supports an optional auto-coupling system for permanent installations; the coupling equipment is not supplied. Allow a minimum pit diameter of 550mm and depth of 600mm at the minimum free float-cable setting. Maximum installation depth is 7m with the 10m cable, leaving at least 3m of cable above liquid level. Lift by the handle. A union, non-return valve and isolating valve are recommended for permanent outlet pipework.
AP50 permits liquids at 0-55°C; AP50B permits 0-40°C. Both specify pH 4-10. The pump housings and vortex impellers are AISI 304 stainless steel. The Basic design has a composite ring stand and housing clips for access during cleaning.
UNILIFT AP35 / AP50 Official Technical Data
UNILIFT AP35B / AP50B Official Technical Data
UNILIFT AP Installation & Operating Instructions
UNILIFT AP35B / AP50B Installation & Operating Instructions
