Early last month, I saw an email from Mark, the purchasing manager of hydraulic system of Caterpillar, an old friend of ours. The subject of the email is "I need help from AAK, I believe". After reading the email about hydraulic threaded cartridge valve, I understood Mark's embarrassment. A small less-known excavator designed by them at the beginning of this year was not smooth in the commissioning process, the response of the excavation part was slow and the power was not enough. After testing, the technical department found that the measured value of the maximum overflow pressure was lower than the specified value, so it was determined that there was a problem with the hydraulic threaded cartridge valve. Mark communicated with the original hydraulic valve supplier. The supplier mentioned that the hydraulic threaded cartridge valve was sampled according to their company's drawings, and all parameter tests were up to standard. The supplier told the fact. He then could only patiently communicate with the design department to see how to modify the hydraulic threaded cartridge valve design, but the design Department said that there was a problem with the installation of the technical team. The company's design and technology departments prevaricate with each other and Mark are caught in the middle, which is very embarrassing and time is also being wasted. If the owner is angry one day, it is estimated that all 3 parties will be criticized. AAK HYDRAULIC VALVE has always been Mark's most trusted supplier of hydraulic valves. I asked Mark to send us the original design drawings of the hydraulic threaded cartridge valve and the working condition requirements of existing equipment, as well as the problems and data encountered in commissioning. 3 days later, we replied to Mark that we have a new design scheme, and we are 90% sure that we can make the hydraulic threaded cartridge valve that meet the equipment requirements, but it will take 2-3 weeks. On the 3rd day after receiving our sample of the hydraulic threaded cartridge valve, Mark happily informed us that the technical department tested AAK hydraulic threaded cartridge valve, the equipment commissioning was smooth, and the reaction and power of the excavation part were normal. The technical department said that the large goods of this hydraulic threaded cartridge valve can only come from AAK, and other hydraulic valve manufacturers are unreliable. Caterpillar designers are also curious about how AAK HYDRAULIC VALVE redesigns this hydraulic threaded cartridge valve? AAK engineering team tried 30 times to design, sampling and make adjustment to find a breakthrough. A sealing ring groove is arranged between the oil replenishment outlet and the oil replenishment inlet of the oil replenishment valve seat of the hydraulic threaded cartridge valve.