Grundfos Unilift AP12 Drainage Pump

The UNILIFT AP12 is a single-stage submersible pump designed for pumping drainage water. It suits groundwater lowering, pumping in drainage collecting wells, pumping in surface water collecting wells with inflow from roof gutters, shafts and tunnels, and emptying ponds and tanks. The pump can be used as a portable unit and handles clean, non-aggressive water and slightly dirty (grey) wastewater.

The stainless-steel pump sleeve is made in one piece and equipped with an insulated carrying handle. The inlet strainer clips onto the pump housing for easy removal during maintenance; it prevents the passage of large solids and ensures a slow flow into the pump, so most impurities never enter it. The stainless-steel pump housing is fitted with an internal riser pipe for high efficiency, and the riser pipe carries a number of holes that cool the motor efficiently during operation. The cable entry has a socket and plug connection for quick dismantling.

The stainless-steel impeller is a semi-open impeller with L-shaped blades and a clearance of 0.4 in. The blades are curved backwards to reduce any harmful effect from solid particles and to minimise power consumption. The stainless-steel shaft rotates in maintenance-free prelubricated ball bearings. The shaft seal combines a mechanical bellows shaft seal and a lip seal with 2 fl.oz. of oil between; seal faces are silicon carbide.

The motor is a single-phase asynchronous dry-rotor motor with built-in thermal protection, IP68 enclosure and class F insulation. Maximum particle size is 0.4 in and liquid temperature range is 32 °F to 131 °F. Across the AP12 range Grundfos publishes a maximum flow of 140 GPM and a maximum head of 52 ft; both belong to the AP12.50.11 and are range ceilings, not a single duty point. The pumps are not designed for continuous operation.

• One-piece stainless sleeve with an insulated carrying handle — built to be moved and dropped in.
• Clip-on inlet strainer — comes off by hand for cleaning, and slows the inflow so most impurities never reach the pump.
• Internal riser pipe — raises efficiency and, through its cooling holes, keeps the motor cool in operation.
• Semi-open backswept impeller with 0.4 in clearance — reduces the effect of solids and holds power consumption down.
• Silicon carbide shaft seal — mechanical bellows seal plus lip seal with an oil chamber between them.
• Plug-and-socket cable entry — the cable comes off for quick dismantling.
• Built-in thermal protection on single-phase motors; IP68, insulation class F.
• CSA C/US approved.

• Groundwater lowering
• Pumping in drainage collecting wells
• Pumping in surface water collecting wells fed from roof gutters, shafts and tunnels
• Emptying ponds, tanks and containers
• Rainwater, drainage water and water from flooding; ditch drainage water
• Water from rivers and lakes; pool water
• Effluents from showers, washing machines and sinks below sewer level
• Domestic effluents from septic and sludge-treating systems
• Non-permanent heavy-duty use by installers and light industry, as a portable pump

Automatic models carry an integral float switch (the A in the type designation) and start and stop on level. The manual model has no level switch and runs whenever it is energised. On automatic models the free cable length between the float switch and the pump handle sets the start/stop difference: a longer free cable means fewer starts and a larger level swing, a shorter one means more frequent starts and a smaller swing. Minimum free cable length is 4 in.

The 115 V models ship with 25 ft of cable and a NEMA 5 plug. The 230 V models ship with 25 ft of cable and no plug — they are wired in on site.