AAK 3 Skills Solved the problem of Hydraulic Counterbalance Cartridge Valve Caused by Back Pressure and helped Dorian's Equipment to be Promoted Smoothly Dorian is from a Greek hydraulic equipment company and is responsible for the procurement of hydraulic components. At the beginning of the year, they developed a new hydraulic crane, which requires the use of hydraulic counterbalance cartridge valve. Dorian worked with a local manufacturer to make samples. During the equipment commissioning, it was found that the hydraulic counterbalance cartridge valve had no overflow function due to the back pressure. The hydraulic system was tested separately, but it was normal. Dorian felt that there was a hidden danger in the original design of the hydraulic counterbalance cartridge valve. The engineer thought that the function of the hydraulic counterbalance cartridge valve was not up to standard. Dorian was a little embarrassed. Dorian found website of AAK hydraulic valves on Google, and noticed that AAK had been supplying first-line brand hydraulic valves such as HydraForce, SUN Hydraulics, and HAWE for many years. Maybe he saw hope and sent an email to ask for help. According to what he said, the hydraulic counterbalance cartridge valve has no overflow function under the influence of the back pressure of the closed central circuit. I told him that it was probably a flaw in the design of the original hydraulic counterbalance cartridge valve. According to his hydraulic schematic diagram and original drawing of hydraulic counterbalance cartridge valve, AAK engineer not only determined that the problem was in the original design, but also had a solution. After knowing these, Dorian asked AAK to make samples. After 50 days, AAK sent 10 hydraulic counterbalance cartridge valve samples. 4 weeks after AAK hydraulic counterbalance cartridge valve samples were sent, Dorian told me that the equipment debugging was smooth and the market promotion had been started. I was asked to wait patiently for the batch order. The rapidity and stability of AAK optimized hydraulic counterbalance cartridge valve is the key to smooth equipment commissioning. It solves the contradiction between the rapid response and stability of the equipment in the early stage, and the flow change is moderate, the movement is stable, the safety overflow function is not affected by the back pressure, which can be applied to the closed center and open center hydraulic systems. 1. The middle section of the hydraulic counterbalance cartridge valve spool is provided with an inner concave ring, which is also the valve inlet. The right end of the inner concave ring has a cone, on which there is a two-stage stepped taper ring. The cumulative area of the cone is the same as the area of the cylinder end face at the right end of the counterbalance cartridge valve spool.