Principles - a technical overview

A high pressure pump produces water at pressures up to 4100 bar.Some entry level water jet machines have a direct driven pump that produces water at 1500 - 2000 bar, this is sufficient to cut metal up to 20mm and softer materials up to 50mm thick. Most machines are specified with an intensifier pump that can deliver pressures up to 3800 bar, suitable for cutting metals and other materials up to 150mm thick.

The high pressure water is delivered to a cutting head by a small bore stainless steel pipe. At this point it is passed through a very small orifice made from sapphire or diamond which produces an extremely thin, high velocity jet of water. A metered amount of abrasive particles, such as sand, is then mixed with this high velocity jet of water and focused in another nozzle called the focusing tube.

The work piece to be cut rests on support grids over a tank of water. The water jet penetrates through the material and moves relative to the XY coordinates of the bridge supporting the cutting head. The excess water jet energy that exists after the jet has cut through the material, is absorbed by the tank of water. The cutting water and sludge can be filtered by an optional sludge removal system.

Principles continued. Pump types - fixed or intensifier?