Seaflo

Choosing pump size and switching type

Bilge, washdown and freshwater pumps are all sized by flow rate and head, the vertical lift and pipe resistance the pump has to work against, so matching a pump to the job means checking rated flow at the head you actually need rather than the headline figure on the box, which is usually the pump's maximum output against no resistance at all. Most Seaflo pumps run on 12V or 24V DC, so confirming your system voltage before ordering avoids a straightforward but easily missed mistake.

Automatic bilge pumps rely on a float switch to sense rising water and start the pump without manual intervention, which matters most for spaces that are not checked regularly, while washdown and freshwater pumps are more often switched manually or via a pressure switch that senses when a tap opens. Macerator pumps need pipework sized to avoid blockages and should be plumbed with a proper seacock and non-return arrangement rather than tied directly into other plumbing.