TL;DR
Abrasive stoppages are usually a clogged abrasive line, empty hopper, or a worn or blocked metering orifice. Check the hopper level first, then inspect the abrasive line from hopper to nozzle.
What you might see
- cut not penetrating full material thickness
- abrasive flow alarm or low abrasive sensor
- grinding noise at the nozzle drops off
- cut parts show waterjet-only surface finish rather than abrasive finish
Likely causes
Abrasive hopper empty or bridged preventing flow
Metering orifice clogged with clumped wet garnet
Abrasive feed line kinked or blocked
Worn metering orifice bore enlarging and causing inconsistent flow rate
Required tools
- Thin wire probe for orifice clearing
- Replacement metering orifice (spare on hand)
- Dry garnet abrasive (correct mesh specification)
- Flashlight for feed line inspection
Safety first
- Garnet abrasive dust is a respiratory hazard. Wear appropriate respiratory protection when cleaning around the abrasive system.
- Do not attempt to clear an abrasive line while the pump is pressurized.
Procedure
- 1
Stop the cut cycle and confirm pump pressure is at zero before accessing the abrasive system.
- 2
Check the abrasive hopper level. Refill with dry garnet of the correct mesh specification if the hopper is empty or low.[1]
- 3
Inspect the abrasive for moisture clumping. Clumped garnet will bridge across the hopper outlet. Break up any bridges and ensure garnet flows freely.
- 4
Locate the metering orifice on the abrasive line and disassemble. Inspect the orifice bore for clumped garnet or wear.[1]
- 5
Clear any blockage using a thin probe. Replace the metering orifice if the bore is visibly enlarged or out of round.
- 6
Inspect the flexible abrasive delivery tube from hopper to cutting head for kinks, tight bends, or wear-through holes.
- 7
Reconnect and run an abrasive flow test by cutting air into the tank. Visually confirm garnet flow at the nozzle exit before cutting material.
Sources
Flow International Flow Mach 200 / 500 / 700 Waterjet Cutting Machine general technical documentation, Flow International
Flow International waterjet operator manual, abrasive system maintenance and troubleshooting (general)
More guides for Flow International Flow Mach 200 / 500 / 700
How to troubleshoot low intensifier pump pressure on a Flow Mach 200 / 500 / 700 waterjet
Low intensifier output pressure is usually worn high-pressure seals, check valves, or a damaged intensifier cylinder. Inspect the check valve cartridges and HP seals before condemning the cylinder.
How to diagnose and replace a worn orifice or nozzle on a Flow Mach 200 / 500 / 700 waterjet
A widening kerf, taper on cut parts, or reduced cutting speed nearly always means the orifice jewel or focusing nozzle is worn. Replace both as a set when cut quality degrades.
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