DI in attached drawing: ID of boron carbide nozzle, 8mm
D2 refer to ID of bellmouth orific, 12mm
18: Refer to OD of boron carbide layer, 18mm
22: Refer to ID of chrome-plated steel nozzle, including thickness of nylon gasket, 22mm
G3/4"-14 refer to the thread size 3/4". 14tooth. Also OD of whole nozzle.