Pilot Operated Hydraulic Relief Valve

James is the purchasing director of one of our American Hydraulic customers. They are the top 3 in the construction machinery industry in the United States, and their market share is increasing year by year. James is also doing well. In May last year, the MP550-HDD-18 cement delivery pump supplied by their company to a local construction company often failed to reach the rated value for the system pressure during use, and the oil pressure of the hydraulic system can only reach 12MPa. After disassembling the hydraulic system, the engineer found that the joint surface between the conical pilot valve body and the valve seat of the hydraulic relief valve was grinded out with a circle of uneven groove line with a depth of about 1mm for unknown reason. The hydraulic oil flowed back to the oil tank from this groove, and the hydraulic relief valve had no sealing function. The customer wanted Jamesâ??s company to replace the hydraulic relief valve of the same model within 2-3 weeks. If they miss the time, the project progress will be affected. When James purchased this hydraulic relief valve from the original German hydraulic valve supplier again, he was told that they produce this hydraulic relief valve no longer. If he wanted to re-produce it, it would take 35 days and modify the production process and auxiliary equipment, which would require an additional cost of more than 30,000 US dollars. This style of hydraulic relief valve was just purchased by James 2 years ago. When he reported this situation to the president, the president didn't understand why he didn't have an alternative hydraulic valve manufacturer. James realized that the president was unhappy. When he sent the anatomical drawing of this hydraulic relief valve to more than 20 hydraulic valve manufacturers, almost all said that they have no hydraulic relief valve with such structure, James was a little flustered. In March this year, James just purchased a batch of high-precision hydraulic relief valves from AAK. He wanted to see if AAK had a way to solve this thorny problem. When he sent us the pictures of this hydraulic relief valve made in Germany, we asked him to send us the whole complete technical drawings, as well as the use environment and working conditions. The pressure of this hydraulic relief valve is 31.5Mpa and the flow is 200L / min, which is basically consistent with the parameters of the hydraulic relief valve we supplied to them before. However, there is a fatal problem that the internal structure, appearance, shape and size are inconsistent with those of the hydraulic relief valve they purchased in Germany, so it is difficult to install on the transmission line. After learning that the only way is to meet the requirements of the transmission line at the construction site in the United States, AAK engineers designed a new hydraulic system with two pipe joints and an oil plug according