When operating a sinker EDM, don’t underestimate the performance impact of flushing and fluid flow. An inefficient back-burn punch setup, for example, can lose flushing during operations. This issue can lead not only to scrapped parts or rework, but it also extends your customer lead-times. To prevent such issues, it is well advised to consider applying flush pots. By using flush pots, manufacturers can steadily improve flushing and fluid flow in their shop operations.
In some applications where more precise control of flushing and fluid flow are needed for extended operations, a precision in-line needle value can be used. In this configuration, the machine-side flushing is set to maximum pressure, and the precision in-line value is used to regulate the amount of flushing required at the workpiece. This approach prevents the loss of pressure for flushing over time, as it is common practice to use low-pressure flushing (positive flow) when performing back-burn operations.
Below is a list of components and assembly for creating an in-line precision valve. These components can be purchased locally or from an industry supplier, such as McMaster-Carr. A precision analog pressure gauge can also be added to improve the repeatability of external flush settings. However, this configuration is optional and not a requirement. Once assembled, this setup is connected between the flush pot and the machine’s auxiliary flush port.