Patent ID: 8650673

Claim:
A sump for a swimming pool drain comprising: a sump housing in a bottom of a swimming pool; a grate disposed on the sump, the grate comprising one or more slots therethrough; a first suction line comprising a first diameter coupled to the sump housing at a first end of the first suction line and coupled to a second suction line at a second end of the first suction line opposite the first end, the second suction line comprising a second diameter smaller than the first diameter; a low velocity flow zone extending from the one or more slots in the grate and through the first suction line to the second end of the first suction line, the low velocity flow zone having a total length of not less than about 24 inches from all of each of the one or more slots to the second end of the first suction line, the first diameter being sufficiently larger than the diameter of the second suction line so that when a flow velocity through the second suction line is approximately 6 feet per second a flow velocity within the first suction line is approximately 1.5 feet per second or less and a flow velocity throughout the low velocity flow zone is approximately 1.5 feet per second or less throughout the low velocity flow zone.