Over the past 2 years, Peter, who is from ST hydraulic equipment manufacturing company, has been very smooth in purchasing hydraulic valves in Ningbo. He and I often have some communication via emails, but there is no cooperation yet due to the high price. A batch of hydraulic directional control valves he purchased last year had problems. Six months after shipment, the customer found that the hydraulic system could not operate because the valve spool of the hydraulic directional control valve was stuck, and asked ST company to solve it within 30 days. Peter communicated with the original manufacturer of this hydraulic directional control valve but no gain. The manufacturer thought that the hydraulic oil was not clean or there were problems in installation, because their hydraulic directional control valves passed the test before shipping. The boss asked Peter to check with other manufacturers and be sure to solve customer complaints within 30 days. Most manufacturers advised that they have no existing stocks that are exactly same as this hydraulic directional control valve, and they are also not willing to produce it especially for such a small quantity. Some manufacturer advised that they can customize it for Peter, but it will take more than 50 days and also costs a lot. Two weeks passed but still no solution, which makes Peter haggard. Peter thought of AAK and emailed us to ask if there was a hydraulic directional control valve of the same model, and the faster the delivery, the better. After reading this email, I understood that there was a problem with the hydraulic directional control valves purchased by Peter. After further communication, I learned that the valve spool of the hydraulic directional control valve he purchased this time was easy to be stuck and complained by customer. According to Peter's drawings and working condition requirements, AAK engineers conducted comparative analysis, and later found that the control principle and size of this hydraulic directional control valve are consistent with one of AAK's existing stock, except that the design method is different. I immediately answered Peter that AAK had 100 hydraulic directional control valves in stock. At the same time, I emailed the drawings of AAK hydraulic directional control valves and asked Peter and his engineers to verify whether AAK hydraulic directional control valves met their requirements. The next day, Peter said that their engineers thought AAK hydraulic directional control valve could not be used because some designs were fundamentally inconsistent. I suggested to him: if you want to solve the customer complaint within 30 days, perhaps purchasing this hydraulic directional control valve is the best choice. To believe in the analytical ability of AAK, you should try our hydraulic directional control valves first. If it really cannot be used, AAK shall bear all expenses for goods return.