Abstract: A pipe bend for a siphon installation formed by two straight pipe parts and a curved pipe part connecting these parts, which pipe bend is provided with a guide extending from the curved connecting part in one of the pipe parts for guiding a liquid flow in that pipe part. The flow guide can include a rib protruding from a side wall of the pipe part and extending at an angle to the center line thereof. A siphon installation provided with such a pipe bend, in addition to a liquid discharge system in which such a siphon installation is arranged, is also disclosed.