AAK hydraulic relief valves with large flow was intact after 1 year, Patrick never dared to move orders again Patrick is from a Dutch hydraulic equipment manufacturing company. Since the beginning of last year, the order of a high-precision and large flow hydraulic relief valve has been tossed for more than half a year, and finally he had to return to AAK to place the order. At the beginning of last year, Patrick sent an inquiry for 30 hydraulic relief valves. 3 days after AAK's quotation, Patrick placed the sample order, but there was no reply after the hydraulic relief valve samples were sent. It was not until the beginning of last month, that is, more than half a year later, Patrick sent an e-mail asking whether each hydraulic relief valve in the regular order could guarantee the same quality as the sample? I felt something was wrong. After several rounds of e-mail communication, I learned that Patrick gave the regular order to another hydraulic relief valve manufacturer, and the price was more than 15% cheaper than AAK. However, after 8 months, the main valve spools of some hydraulic relief valves were worn, resulting in loose fitting of valve body holes and even grooves, resulting in failure to raise the pressure of the equipment system. According to the feedback of the original hydraulic valve manufacturer, this hydraulic relief valve has large flow, high frequency of use, high accuracy of valve hole, and wear is normal. 2 months later, more and more complaints were received, but the original manufacturer surrendered and asked Patrick to source other hydraulic relief valve manufacturers. Patrick was a little scared and had to go back to AAK. Because the AAK hydraulic relief valves used in the original design equipment has not been abnormal for more than 1 year, it would be better to choose AAK even if the price is more expensive for 15%. If the hydraulic relief valves with large flow need to have high accuracy and be durable for more than 1 year, or more than 2 million times, the material selection, processing and quality awareness are indispensable. For the hydraulic valve manufacturers who can guarantee these 3 points at the same time, you may not find a third one in Ningbo. 1. AAK has American high-precision CNC honing machine tools. The surface roughness after honing is less than Ra0.8 and the cylindricity can reach 0.5m. Axis straightness can reach 1�¼m. It is especially suitable for finishing the valve hole of large flow hydraulic relief valves. The processing aperture range is 5-500mm, and the depth diameter ratio can reach 10. For large flow hydraulic relief valves with large aperture, most hydraulic valve manufacturers can only reach 2-3m. 2. According to the large flow rate of this model, after 2 weeks of comparative testing, AAK has determined the German 20CrNi2MoV high-carbon bearing steel as the main material of the valve body.