Symptoms that alert a fabricator that it's time to change the nozzle are inside cuts that become larger and outside cuts that become smaller than intended. Also, operators may see poor cut quality in one or more directions.
Repair time takes 5 minutes to 10 minutes to switch out the nozzles.
Diagram of Waterjet cutting machine |
· Track hours on the nozzle and begin to monitor cut quality and tolerance as hours mount.
· Adjust kerf compensation as required to remain within tolerance limits.
Older nozzles don't necessarily have to be tossed in the garbage. Save them for less critical work.
Clogging of the abrasive nozzle also can cause problems. Clogs can occur from too much abrasive or an abrasive mesh size that is too large for a particular orifice diameter, large contaminants in the abrasive, or the nozzle tip contacting the workpiece during piercing or cutting.
A clog is easy to detect. The waterjet stops. Water may back up in the abrasive feed tube all the way back to the minihopper until the machine is stopped.This entire feed line and the minihopper must then be emptied and dried out entirely.
Because of the speed at which the abrasive is moving, generally the nozzle is clogged to the point where it cannot be used anymore.Sometimes people have success at clearing clogged nozzles by turning them upside down and turning on the water at lower power. The time necessary to repair or replace components related to clogging can be anywhere from 5 minutes to 30 minutes.