Nozzle life extension

Water jet cutting inserts based on synthetic diamond can dramatically improve the life of nozzles that deliver the cutting jet.


Element Six, a producer of synthetic diamond for industrial applications, has entered the water jet cutting market with a range of water jet cutting inserts based on synthetic diamond that can dramatically improve the life of nozzles that deliver the cutting jet.


The diamond inserts, developed by Element Six, have undergone testing with a number of leading water jet manufacturers, leading to approval by several companies in Europe. Tests in the North American market are expected to be complete in mid-2007.


Water jet cutting is a technique that has a number of industrial applications.  It is capable of cutting everything from chocolate bars to steel, paper to plastic or wood and granite. Currently the market for such equipment is growing at a rate of around 12 per cent a year, according to the company.


In use, a fine jet of water (plus abrasive for cutting harder materials) is produced under high pressure that can be used to cut materials. To do so, the water is forced through a nozzle assembly that contains an insert. But if the insert is affected by wear, misalignment and damage, it can causing a deterioration in the performance of the system. 


‘Element Six has developed a range of synthetic diamond inserts that can outperform other insert materials used within the nozzle,’ explained René Diks, marketing and sales manager for industrial components at Element Six. ‘In comparison with sapphire inserts, for example, the life of a diamond insert is fifteen to twenty times better.’ 


Tests proved that after 1000 hours of operation with pure water at 3500 bar there were no measurable changes in jet quality and water usage. Tests with abrasive water jet cutting proved that after 100,000 cycles (on/off cycles) there were no measurable changes in jet quality and water usage.


The nozzle inserts are available in a variety of bore diameters ranging from 100 µm to 400 µm. The choice of geometry its determined by the application, with diameters between 100 µm and 200 µm optimised for pure water cutting, and the larger diameter range of 200 µm to 400 µm designed for abrasive cutting, though specially tailored bore geometries can also be offered. The outer geometry of the insert is fixed and, therefore, the mounting procedure for all bores is similar.