Patent ID: 9739064
Date: 2017-08-22
CPC Classifications: E03B,E04D,F16L,Y02A,Y10T

Claim:
1. A drainage system, comprising: a collector which is arranged to collect liquid; a drainage pipe having a pipe inlet that opens into the collector such that liquid collected by the collector drains through the pipe inlet, wherein the drainage pipe is provided with a vent spaced away from the pipe inlet, the vent being arranged such that, when liquid collected by the collector occludes the pipe inlet, liquid flowing through the drainage pipe draws air into the drainage pipe through the vent, a vent duct which extends away from the vent, the vent duct having a vent inlet arranged to draw air from a level above the pipe inlet during normal use, and a vent outlet which opens into the drainage pipe through the vent, wherein the vent inlet is arranged to open into the collector, wherein the vent inlet is arranged such that in use, a threshold level of liquid which accumulates within the collector inhibits flow of air through the vent inlet, and wherein a portion of the vent duct extends downwardly to the vent inlet.