At M.W. Watermark (http://www.mwwatermark.com/), we are frequently asked how to set and check relief valve pressure on a filter press air hydraulic system. The following instructions and video are for a modular-style air hydraulic unit. In the video, you will learn how to set your relief valve pressure and your working pump pressure. If you have any questions, don't hesitate to call our service and sales team at 616-399-8850. We are located at 4660 136th Ave. Holland, MI 49424-9452.