Dimon is a new buyer of a hydraulic equipment manufacturing company in the United States. In the second half of last year, he purchased 100 hydraulic needle valves from an old supplier. After receiving the goods, the hydraulic needle valves were installed on the equipment. A few months later, some users complained that the pressure supply of some equipment was insufficient. Their technicians judged that the radial jamming of the valve spool of the hydraulic needle valve resulted in no flow regulation, which would lead to the failure of the power unit. The hydraulic needle valves need to be replaced with new ones as soon as possible to eliminate user complaints. His boss is not very satisfied that problem happened on even such a small number purchasing of hydraulic needle valves. Dimon is confused why the hydraulic needle valve supplier who had cooperated for 2 years would have such quality problems. He sent some problematic hydraulic needle valves back to the factory. The manufacturer replied that the accuracy of these hydraulic needle valves met the standard, but a small deviation in the size of the valve spool was caused by the deviation of the assembler. At that time, several valves were assembled at the same time in the assembly workshop, and a few deviations were difficult to avoid. Dimon realized that even the original manufacturer replaced the hydraulic needle valves with new ones, it still can not solve the problem of the radial jamming of the valve spool for 100%. He was afraid that if there were more user complaints, could he keep his job during the probation period? Dimon decided to find a new supplier of hydraulic needle valves. He left a message on our website: Can you solve the problem of radial jamming of the valve spool of hydraulic needle valve? At first, it was hard to answer this question. After several rounds of communication, we learned the story of his purchase of these 100 hydraulic needle valves. After reviewing the working conditions and drawings of hydraulic needle valve from Dimon, as well as the pictures of hydraulic needle valves from the original supplier, AAK suggested him trying samples directly. 20 days later, AAK sent 10 samples of hydraulic needle valves made per his requirements. Two months later, Dimon sent an email to us saying that he selected 5 factories from more than 20 hydraulic needle valve manufacturers to make samples. Only the samples from AAK and another factory did not have the problem of radial jamming of valve spool during the test. Their engineers suggested that AAK should be selected to replace the 100 hydraulic needle valves with potential quality problems, because the parameters of AAK hydraulic needle valve are the most stable. The boss knew that he dared to develop new suppliers and solved the hidden quality problems, although the probation period is not over yet, Dimon was approved to become a regular in advance. He told us this story privately.