AAK Hydraulic Pilot Operated Relief Valve Advantage & Feature

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

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