Grundfos Grundfos Unilift AP
Grundfos Unilift AP submersible pumps for drainage, grey water and wastewater, with a free passage of 12, 35 or 50 mm.
Unilift AP is the Grundfos range of submersible pumps for drainage and wastewater, with all hydraulic parts in stainless steel. AP12 has a semi-open impeller and passes particles of up to 12 mm, for drainage water and grey water; AP35 and AP50 have a vortex impeller, with a free passage of 35 and 50 mm, for water with fibres and effluents, and AP50 also for domestic wastewater including discharge from toilets. The AP35B and AP50B variants (AP Basic) can be mounted on an automatic coupling system with guide rails, and AP50B is approved to EN 12050-1 for pumping stations handling faecal matter. The cooling jacket allows continuous operation even with the pump partly submerged.
The code has the form AP35B.50.08.A1V: 35 is the maximum particle size, in mm, B marks the Basic variant, 50 is the nominal discharge diameter, in mm, and 08 is the power P2 divided by 100 W; A shows automatic start with a float switch, 1 or 3 the single-phase or three-phase motor, and V the vortex impeller. For a quotation, send us the code from the nameplate, the voltage and the pumped liquid. When the item is available locally or at the supplier, delivery takes 24–72 h, and on order usually 1–4 weeks.
Models and codes
| Code | Note |
|---|---|
| AP12.40.04.A1 | Drainage, 40 mm discharge, with float switch, single-phase. |
| AP12.50.11.3 | Drainage, 50 mm discharge, three-phase, without float switch. |
| AP35.40.06.A1V | Vortex impeller, particles up to 35 mm, with float switch, single-phase. |
| AP35B.50.08.3V | Basic variant, 50 mm discharge, three-phase. |
| AP50.50.11.A1V | Vortex impeller, particles up to 50 mm, with float switch, single-phase. |
| AP50B.50.15.3V | Basic variant for wastewater with faecal matter, three-phase. |
Key specifications
| Maximum head | 18 m (AP12, AP50B); 13 m (AP35, AP35B, AP50) |
|---|---|
| Maximum flow | 32 m³/h (AP12, AP50); 29 m³/h (AP50B); 21.6 m³/h (AP35, AP35B) |
| Liquid temperature | 0…+55 °C for AP12, AP35 and AP50; 0…+40 °C for AP35B and AP50B; without float switch and if the liquid does not touch the cable and plug, AP12, AP35 and AP50 withstand up to +70 °C for under 3 minutes in every 30 minutes |
| Liquid pH | 4–10 |
| Free passage and impeller | 12 mm, semi-open impeller (AP12); 35 and 50 mm, vortex impeller (AP35, AP50 and B variants) |
| Maximum immersion depth | 2 m with 5 m cable; 7 m with 10 m cable |
| Installation | free-standing, on the sump floor (AP12, AP35, AP50); on automatic coupling with guide rails (AP35B, AP50B) |
The Grundfos data booklet Unilift CC, KP, AP and KPC (04.2025 edition) covers AP12, AP35, AP35B, AP50 and AP50B, with no withdrawal notice.
Frequently asked questions
What is the difference between AP35 and AP35B?
Both have a vortex impeller and a free passage of 35 mm. AP35 is installed freestanding on the basin floor and handles liquid up to +55 °C, while AP35B (AP Basic) can be mounted on an automatic coupling with guide rails and handles liquid up to +40 °C.
Which Unilift pump is used for wastewater with faecal matter?
AP50B, with a free passage of 50 mm, approved to EN 12050-1 for pumping stations handling faecal matter. AP50 is intended for water with fibres, effluents and domestic wastewater including discharge from toilets.
What data do you need for a replacement Unilift AP pump?
The code from the nameplate (for example AP12.40.08.A1), the supply voltage and the starting method: with a float switch or from a control box. If the nameplate is missing, the type of pumped water, the flow and the head help us.
Other Grundfos series
We quote the Unilift AP pump and its accessories by code; the construction of the basin, installation and connection to the panel are outside our quotation.
Updated: 2026-11-12