For the hydraulic counterbalance valve with a service life of 2 million times, A

Patrick is the purchasing manager of a hydraulic equipment company in Italy. At the beginning of last year, they sold a batch of shield machines to Portugal, which were complained by customers within half a year. During the operation of the shield machine, the grease pump at the tail of the shield had no pressure. It was found that there was leakage in the hydraulic counterbalance valve of the shield machine. After disassembly, it was found that the fitting clearance between spool and valve hole of hydraulic counterbalance valve was worn. The original hydraulic counterbalance valve manufacturer said that the wear of hydraulic counterbalance valve was caused by the construction environment and pressure requirements of shield machine, and the valve spool of hydraulic counterbalance valve was made of 12L14 steel imported from the United States with good wear resistance, which means there is nothing else he can do. Patrick was helpless, and his engineers were not happy that he found such an irresponsible hydraulic counterbalance valve manufacturer, requiring him to find a manufacturer that has hydraulic counterbalance valves with a service life of more than 2 million times.

Patrick contacted more than 20 hydraulic counterbalance valve manufacturers, and AAK also received his drawings. Combined with the working condition information, if the service life of this hydraulic counterbalance valve needs to be more than 2 million times, material selection, processing accuracy, durability testing, these 3 aspects are indispensable. We told Patrick that we could test the sample directly. If the sample failed, we were willing to return the development cost. 2 weeks later, Patrick paid $600 for the development and informed that 3 hydraulic counterbalance valve manufacturers were testing samples at the same time. He would only choose 1 manufacturer as their sole supplier of this hydraulic counterbalance valve.

After 45 days, we sent the samples of hydraulic counterbalance valve. 2 months later, Patrick wanted to order 500 hydraulic counterbalance valves at one time. After more than half a year of comparison, AAK hydraulic counterbalance valve was the only one that passed the durability test of 2 million times. His boss was also very happy to find such a manufacturer. Patrick wanted to know how AAK hydraulic counterbalance valve did in terms of material selection, processing accuracy and durability test?

By doing 3 points, AAK differs from the peers, but also declares that there are no peers for hydraulic counterbalance valve with a service life of 2 million times.

1. AAK adopts 20CrNi2MoV high carburized bearing steel imported from Germany. Combined with carburizing pretreatment process, through secondary quenching + cryogenic treatment + low temperature tempering process, it is cooled to 650 ~ 700 ℃ and put into the furnace. After cooling to 450 ~ 500 ℃, it is discharged from the furnace. The microhardness can reach 237 ~ 247 HV, and its wear resistance and fatigue resistance are improved by more than 3 times.