Pressure group with 2 twin impeller centrifugal pumps complete with base with antivibration device, suction and delivery manifold, ball valve and non-return valve, available with or without 2 membrane tanks. And it has an electric box complete with a general switch and thermic switch. And low-tension ancillary circuit complete with transformer and protecting cut-outs. It is suitable for water supply from wells and to increase pressure in a water system.