Just yesterday, I received a repeat order from Andy for a hydraulic flow control valve, which is just 3 months away from the delivery time of the last batch of hydraulic valves. The American customer Andy, started to communicate with us in 2019. Maybe it was just not the right time, we still didn't partner with each other till the beginning of this year. Because of encountering a Waterloo at the previous hydraulic valve manufacturer, he turned the tables at AAK and regained his confidence. At the end of last year, Andy purchased a batch of hydraulic flow control valves from a hydraulic valve manufacturer. Because 20% of the shipments leaked, he encountered customer claims. The old hydraulic valve manufacturer was unwilling to bear the claim or re-produce. The customer kept pushing for replacement hurriedly. The owner asked him to find a high-quality hydraulic valve manufacturer to reproduce the goods for the customer. Andy had a big headache at that time. The replacement quantity is not big, the hydraulic valve manufacturers with exquisite quality were unwilling to produce the small quantity for him. The hydraulic valve manufacturers who were willing to produce this quantity, were not able to meet the customer's requirement about the roughness of the hydraulic flow control valve. He ran into a wall everywhere, which made Andy haggard. When Andy contacted with AAK HYDRAULIC VALVE, we are willing to cooperate with her to solve this difficult problem. We tested the leaked hydraulic flow control valve sample. The reason for the leakage is the roughness of the mounting surface of the hydraulic flow control valve. According to the customer's service conditions, this roughness must be controlled at 1.0 M or less. Andy is very confused why 80% of the installation surface roughness of hydraulic flow control valve is up to standard, while 20% is out of this range. The root of this fluctuation is the master's operation method, resulting in human error. The surface roughness is the depth, density, texture of the traces left on the machined surface from the action between the tool and the part surface, which depends on the master's processing technique. Andy is very clear that at present, most domestic hydraulic valve manufacturers generally control the roughness of the installation surface of hydraulic flow control valve at 0.8-1.0 m. The biggest problem is not stable enough. Andy also knows that only AAK controls the roughness value of hydraulic flow control valve within 0.8 M, which can completely avoid leakage outside the hydraulic flow control valve, because of rest assured, Andy decided to repeat the order with AAK HYDRAULIC VALVE.