AAK hydraulic check valve has a pressure resistance of more than 450 bar

At 05:10 this morning, I was listening to music and browsing emails. Billy, who
had no news in 9 months, sent an email. Without reading the email, I could
guess that the hydraulic check valve developed by AAK for 3 months last year
had a result. Opening Billy's e-mail and it is an annual order of 5,000
hydraulic check valves at one time, with about 500 hydraulic check valves
delivered every month. Billy is from a hydraulic equipment company in the
United States, he has purchased a small number of high-pressure resistant
hydraulic check valves from AAK in the past. At the beginning of last year, his
company received complaints from a customer that its high-power bulldozers were
prone to weak starting of the hydraulic system after being used in less than
half a year. The after-sales engineer found that the hydraulic check valves
leaked and can not maintain the pressure and caused the problem.

Billy contacted the original manufacturer of the hydraulic check valves, and
manufacturer advised that the system pressure of the high-power bulldozer
exceeded 450bar, and the opening and closing frequency was also high. When the
hydraulic check valve was in the high-pressure state above 450bar, the valve
spool was worn quickly, and the service life could only be guaranteed as 1
million times. Therefore, it was normal to replace the hydraulic check valves
every half a year. If you want a hydraulic check valve with a service life of 2
million times, you can only purchase it from German HAWE. Billy has no choice
but to make do with the hydraulic check valves of the original manufacturer
first, but the after-sales cost every half a year is really unbearable. Maybe
other manufacturers can offer hydraulic check valves with service life more
than 1 million times. Billy began to contact other factories, including AAK.

After receiving Billy's email, AAK engineers had reached a conclusion according
to the hydraulic check valve drawings and bulldozer working parameters. In
order to exceed the service life of 2 million times of the hydraulic check
valves, we can only test new high-pressure resistant materials. We replied
Billy at that time that according to the existing steel options of AAK, what
your original manufacturer said was right, it can only guarantee the service
life of 1 million times of the hydraulic check valves. However, we are
confident to develop the one of 2 million times, because we have our own R & D
experience in anti-high pressure.

Billy replied directly that AAK would be given 3 months to sample the hydraulic
check valves with pressure resistance above 450 bar. He also frankly informed
that two other hydraulic check valve manufacturers were also making samples. If
all manufacturers fail, they can only buy high-pressure hydraulic check valves
from German HAWE. Three months later, AAK successfully sent 20 hydraulic check
valve samples to Billy. Nine months later, the email came from Billy today.
Billy noted the sample testing results in the email. The bulldozer equipped
with AAK hydraulic check valve was still normal after 9 months, while the
hydraulic check valves from another two manufacturers were eliminated in the
6th and 8th months.

AAK hydraulic check valve has a pressure resistance of more than 450 bar and a
service life of more than 2 million times, because:

1.AAK has engineer who have worked in the Shanghai factory of German HAWE for
11 years and has experience in high pressure resistance.
2.We have tested more than 20 kinds of steel and selected the most suitable
35CrMo steel to produce the valve spool of this hydraulic check valve.
3.Good materials also need good processing. The heat treatment method adopted
by AAK for 35CrMo alloy steel is 845 ℃ annealing, 860 ℃ quenching (oil
quenching) and 200 ℃ low temperature tempering. After this special heat
treatment, its hardness and wear resistance are increased by at least 50%.

AAK hydraulic check valve, can resist pressure of more than 450bar, you can
also have a small try!

https://www.aakindustry.com/info-detai , l/hydraulic-check-valves-aak215

Click to Enlarge