AAK Hydraulic Relief Valve Passed Millions of Tests Under High Stress

Richard is a purchaser of ATOS company in Italy. Last September, ATOS received
a complaint from a South African customer that the starting pressure of the
hydraulic pump was often insufficient recently. The field engineer analyzed
that the valve spool spring of the pilot hydraulic relief valve of the
hydraulic pump was deformed, resulting in the unstable pressure of the
hydraulic system. He tried to replace the pilot hydraulic relief valve to solve
the problem. The customer questioned the stability of their equipment because
it had been used for less than 1 year. After learning about it, the boss asked
Richard to solve the customer complaint as soon as possible and replace this
batch of pilot hydraulic relief valves.

Richard wondered about the problem with the pilot hydraulic relief valve. This
pilot hydraulic relief valve was produced by an American company and was re
purchased this time. The original manufacturer replied that this pilot
hydraulic relief valve has been produced according to the standard. The
strength limit and elastic limit of the piano steel wire used meet the
requirements. The problem should be caused by improper use by the user. Of
course, he can not tell the boss of such results. The original manufacturer was
unwilling to take responsibility. Richard contacted nearly 20 hydraulic valve
manufacturers, including AAK hydraulic valve. After several rounds of
communication, Richard eliminated half of the hydraulic valve manufacturers,
and then asked the shortlisted hydraulic valve manufacturers to send their own
ready-made pilot hydraulic relief valves. Their company conducted spring
elasticity test. Finally, 5 manufacturers were selected to send samples for the
second round according to the drawing size of his pilot hydraulic relief valve
and improve the spring elasticity.

After communicating with Richard, we learned that the service limit pressure of
the hydraulic pump is above 350bar and the service frequency is very high.
Although the piano wire spring used by Sun, the original American manufacturer,
is advanced, special materials must be used for this special working condition.
We started to test the special spring first. Richard has received samples of
pilot hydraulic relief valves from other 4 factories, but AAK hasn't sent them
yet. Richard pushed us several times and we advised that we are still in
testing. Richard may think AAK should not be able to do it.

AAK engineers spent 3 weeks, 6 times replacing materials and 9 times proofing,
determined the special alloy steel spring as a trial, and sent the pilot
hydraulic relief valve 30 days later. We specially asked Richard about the test
of the pilot hydraulic relief valves from the other 4 manufacturers. Richard
advised that if AAK pilot hydraulic relief valve could not pass the test, he
would need a new round of looking for suppliers.

A month later, Richard informed that AAK pilot hydraulic relief valve could
still be opened and closed normally after 1 million tests under high stress,
with flexible action and no deformation of the spring, while the samples from
the other 4 manufacturers began to be unstable after 400,000-600,000 tests. AAK
stands out from more than 20 suppliers after 3 rounds of PK. The spring of
hydraulic valve is most afraid of fatigue damage，especially under high stress.
The spring of AAK pilot hydraulic relief valve adopts SiCr alloy steel. The
spring has the characteristics of high temperature resistance, high rigidity,
high relaxation resistance and long fatigue life.

Richard is finally relieved. He asked us to provide two more pilot hydraulic
relief valves, to replace the pilot hydraulic relief valves produced by the
original American manufacturer Sun company, and then start preparing materials
for mass production

AAK pilot operated hydraulic relief valve is unconventional and exceeds the
conventional goods of Sun company in the United States. You can also have a
small try.

https://www.aakindustry.com/info-detai , l/hydraulic-relief-valves-aak137

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