An inlet nozzle assembly includes: a delivery nozzle configured to deliver an effluent stream into an abatement chamber; and a mount configured to couple with an enclosure defining the abatement chamber, the mount being further configured to receive the delivery nozzle, wherein the delivery nozzle is configured to extend from the mount distal from the abatement chamber. In this way, the height of the mount and the location of the abatement chamber can remain fixed for different length delivery nozzles and different amounts of the delivery nozzle extend from the mount, dependent on the length of that nozzle.