hydraulic equipment, which needed to use hydraulic relief valves. The boss asked that the procurement cost of the hydraulic relief valves should be reduced by 15% on the premise of ensuring the quality. He contacted the original hydraulic relief valve manufacturer, and the manufacturer replied that it was impossible. In desperation, he had to find a new manufacturer of hydraulic relief valves. Rodriguez has participated in the Shanghai PTC exhibition and collected some hydraulic relief valve manufacturers, which have great advantages in terms of price. The quotation of some hydraulic relief valve manufacturers is only half of that of manufacturers, and the quotation of some hydraulic relief valve manufacturers is 60% cheaper than that of manufacturers. He is a little surprised that there is such a big difference in the quotation of different manufacturers for the same hydraulic relief valve. They began to test the parameters of the hydraulic relief valves from 3 manufacturers, but did not require to send samples, because the price of was 20% - 30% higher than that of other manufacturers. A month later, the hydraulic relief valve samples from the 3 factories were tested and they all failed to meet the indicators of American manufacturers. The pressure of some hydraulic relief valves could not rise within a few days after the equipment was installed. Rodriguez initially screened the manufacturers of hydraulic relief valves and used the 3 factories with low prices. Maybe it proves that Cheapest is the dearest. He changed his strategy and used the hydraulic relief valve manufacturers with relatively high quotation to test the samples. offers the highest price, but it is still about 30% cheaper than manufacturer. At the same time, promised that the quality could fully match that of manufacturer. According to the hydraulic relief valve drawings and working condition information provided by Rodriguez, sent the samples of the hydraulic relief valves after 25 days. A month later, Rodriguez sent an email that hydraulic relief valves passed the test, and the parameters were benchmarked with those of the original manufacturer, and even some details and appearance were visually more exquisite than those of the manufacturer. He would like to know how makes hydraulic relief valves that surpass American manufacturers has a high-precision CNC machining center imported from and various independent fixtures upgraded and refitted by itself, which eliminates human errors and avoids faults such as stuck valve spool of hydraulic relief valves.