Flaps and lift systems

In short

1. 01A flap opens upwards and is held by a lift fitted to the side panel. On hinges alone it would fall back down.
2. 02Lifts differ in how the flap moves. A stay lift swings it up around its top edge, an up-and-over lift raises it and swings it above the cabinet, and a parallel lift raises it straight up.
3. 03Each lift has a range of flap heights it is made for.
4. 04The power factor is the flap height in mm times its weight in kg.
5. 05The weight is worked out from the dimensions and the board density, about 750 kg/m³. A 596 × 396 × 18 mm flap weighs about 3.2 kg, so its power factor is about 1260.
6. 06Choose the lift force whose range in the catalogue contains the power factor. A lift that is too weak lets the flap drop, and one that is too strong raises it by itself.