Using a ruby or diamond orifice in the abrasive waterjet cutting machine is always a question for the users. This article will give you a deeply looking for this question. Here is several factors about deciding whether to use a ruby or diamond orifice in applications.
I believe cost is the major factor in deciding this question. A ruby (or sapphire) orifice costs in the $15-20 range, and it can last 40 hours in average. If proper break-in procedures are not used, a ruby orifice could fail the first time you turn high pressure water on. Unfortunately, even with proper break-in, the life of a ruby orifice is highly variable.
In different period, the price of diamond is floating. Currently, diamonds cost around $425. With proper water quality and a thimble filter installed at the cutting head, diamonds are guaranteed to last for at least 600 hours. The thimble filter is a very small, very fine filter that is located above the orifice to trap any debris before it gets to the diamond orifice.
Why Diamond Orifice ?
Consider of the long life using, diamond orifice shows its main benefit when processing a long time cutting jobs, especially those materials are very expensive. For example, a 6″ thick Inconel part that takes 20 hours to cut would probably be a poor candidate for a ruby orifice that could potentially fail before completing the cutting processing.When cutting with multiple cutting heads, diamonds are a benefit because you can plan to change them all out at one time, once or twice a year (depending upon usage). Just imagine trying to cut with 4 cutting heads equipped with ruby orifices – the ruby in head one lasts 19 hours, the ruby in head two lasts for 24.7 hours, the ruby in head three lasts 12.5 hours and the ruby in head four lasts 43 hours. You can either change all 4 out when the first one fails or you will end up changing an orifice every couple of hours, HOW BUSY YOU ARE.
Stream quality with a diamond is better than ruby or sapphires, and as a result, cut quality is smoother.
An other factor is nozzle wear. When the time of orifice break, the impact of wear nozzle is much great than usual. The more often you change the orifice, the greater impact on nozzle. On this point, diamond orifice is much better than ruby orifice.
Why Ruby Orifice ?
If none of the benefits of diamonds listed above applies to you or if you are frequently changing nozzle/orifice combinations, you may find it better to stick with rubies. In a job shop or short-run environment, rubies may be a better choice because every time you take the cutting head off the machine to change the orifice/nozzle combination, you increase the risk of debris getting to the orifice that could cause damage. Also, every time the operator changes the orifice, there is a chance that it may accidentally drop in the waterjet tank. (NOTE: always change the orifice and nozzle away from the machine to avoid this.) Dropping a $20 ruby orifice in the tank, while unfortunate, is not heart breaking. Conversely, dropping a $425 diamond orifice in the tank would drastically impact your potential profits on a job.