The basic cutting mechanism is erosions. The required jet pressure decreases with the use of harder abrasives. The cutting energy is proportional to the root of the velocity. This saves energy but will result in degraded surface quality. The opposing cylinders change a large differential volume for a large differential pressure. - as the hydraulic unit in the center pumps in both directions, a high pressure is generated in the water cylinders at either end.
Check valves allow water flow in and out as appropriate.
The ends of the tubes are connected with high pressure swivels. Flow valves are also used to reduce the chances of damage. Some problems with mixing head. - multiple jet, center feed. Good mixing characteristics, but hard to manufacturing. A constant stream of abrasive slurry passes between the tool and the work to provide abrasives and carry away fractured particles.