Caleb is an old customer of AAK in Mexico and has purchased hydraulic cartridge valves from AAK for 4 years. At the end of last year, he emailed me to discuss 3 issues related to hydraulic pilot operated relief valves.
1. The internal leakage of AAK hydraulic pilot operated relief valve cannot exceed 1 drop/min.
2. Can AAK hydraulic pilot operated relief valve achieve multi-level pressure control?
3. Can AAK hydraulic pilot operated relief valve be customized within 35 days?
Looking closely at these 3 questions, I guess he encountered a problem when purchasing a hydraulic pilot operated relief valve. After communication, it was learned that in September, they developed a multifunctional excavator. Due to time constraints, Caleb purchased the hydraulic cartridge valves from a local hydraulic cartridge valve manufacturer in Mexico, but the test run was not successful. Because the internal leakage of the hydraulic pilot operated relief valve is not up to standard, multi-level pressure control also fails, resulting in a weak excavator and unstable operation. After being optimized by the original hydraulic pilot operated relief valve manufacturer, it still failed to meet the standard, so Caleb wanted AAK to try this hydraulic pilot operated relief valve.
AAK engineer's opinion: the valve sleeve and adjusting sleeve of the original hydraulic pilot operated relief valve are the same part. The valve spool is installed from the oil inlet end of the valve sleeve, and then blocked by a retaining ring. The valve spool and valve sleeve are sealed by a gap, which is the source of non-compliance. After discussing with their engineers, Caleb asked AAK to sample in this direction. After 35 days, AAK sent 10 samples of hydraulic pilot operated relief valves.
4 weeks after the samples were sent, Caleb informed us that AAK hydraulic pilot operated relief valve was installed in the system, which solved the problem of causing the excavator to become weak, and the multi-level pressure control function was also available. Yesterday, Caleb emailed us an order for 160 hydraulic pilot operated relief valves. He told me, this is the first order from this customer. His boss is very satisfied with AAK hydraulic piloted operated relief valve, which has the performance advantage of internal leakage, as well as multi-level pressure control feature, allowing them to obtain customer order for excavators.
AAK hydraulic piloted operated relief valve, with internal leakage of 1 drop/min, and can achieve multi-level pressure control functions. Starting with the sealing method, we divide the valve sleeve and adjusting sleeve of the hydraulic relief valve into 2 parts. The valve sleeve and valve spool are sealed with a cone, as follows:
1. The valve spool of the hydraulic relief valve is located inside the valve sleeve, and the adjusting sleeve and the valve sleeve are fixedly connected in a bayonet type. The spring is inside the valve spool, with one end against the valve seat and the other end against the bottom of the valve spool.
2. The other end of the valve seat is against the pilot valve spool inside the adjusting sleeve, and there is a pressure regulating spring inside the pilot valve spool. The valve sleeve has 2 step through-holes in the axial direction. The junction between the large hole and the small hole is processed into a conical surface, and the valve spool and valve sleeve are sealed at the conical surface.
3. A radial hole for oil control passage is provided between the valve spool and the valve seat. There is a steel ball between the valve seat and the pilot valve spool. There is a circular hole on the valve seat that communicates with the radial hole to accommodate the steel ball, and there is a blind hole on the pilot valve spool to accommodate the steel ball.
AAK hydraulic piloted operated relief valve, internal leakage of 1 drop/min, and multi-level pressure control function, you can also try it!
https://www.aakindustry.com/info-detail/relief-valves-aak538