Patent ID: 7497772

Claim:
A two piece quick change flow duct for creating a branch circuit comprising: a two part duct branch and plate holder for attachment to a primary duct and for diverting flow therefrom; the duct branch comprises a first lower base portion and a second upper nozzle portion matingly engaging the first lower base portion, the first lower base portion includes a first open faced U-shaped base plate holder portion that is integral with the lower base portion of the duct branch, the second upper nozzle portion including an open faced U-shaped nozzle plate holder having a cross section dimension that is less than the cross sectional dimension of the open faced U-shaped base plate holder, the first and second open faced U-shaped plate holders removeably matingly engaging each other in a snap fit to form a plate holder snug fit plate holder slot, said slot is closed on three sides, comprising reinforcing ribs on flanges, transverse to the flow path, for removeably receiving a restrictor plate in a snug fit, said lower base portion having a concave surface complimentary with the primary duct for sealingly matingly engaging and mounting to the primary duct ( 18 ) without completely severing said duct into separate pieces. wherein the plate perimeter conforms with the slot interior and the height of said slot is approximately equal to 0.06 inches to receive the plate in a snug friction fit, said restrictor plate having a gasketing material applied to the faces thereof and a flow control aperture therethrough for direct insertion into the plate holder, said restrictor plate having a flow control tag such that when the plate is received in the plate holder, flow control aperture characteristics are easily identifiable and said plate restricts flow in accordance with the selected plate aperture, wherein the branch circuit can be easily removed by separating the nozzle portion from the base portion.