AAK hydraulic check valve , Denison hydraulic pump components in use

When I got up to go to the bathroom at 1 a.m. last Monday, my wechat phone
rang. It was from Carl, the purchasing manager of Denison hydraulic pump
company in the United States. I was very surprised by this phone call.
Generally, we communicate with Carl in the form of e-mail and have never used
wechat phone. Carl firstly said sorry to disturb my rest, and asked if I could
arrange a video conference at 8:00 tomorrow morning. He needs to discuss a
troublesome problem with our technical team.

I'm concerned that the communication on the phone will not be clear, and asked
him to send me a written email first, and then I'll reply to him. Half an hour
later, a detailed email with a schematic diagram of the hydraulic system came
in. Last week, the hydraulic pump supplied by them encountered problems with
his customer. The customer's hydraulic system has been shelved for half a year,
and now it needs to be driven. After the operator starts the hydraulic pump,
there is no pressure in the hydraulic system. The field engineer judged that
there was no flow output of the hydraulic pump, but after inspection, it was
found that the rotation direction of the motor was consistent with that of the
hydraulic pump, and the oil level, oil temperature and viscosity of the
hydraulic pump met the working conditions. The suction system of the hydraulic
pump was replaced, including the oil suction pipe and filter. After startup,
there was still no flow output. The transmission parts inside the hydraulic
pump are intact without falling off, fracture and blade jamming. A week has
passed and no reason has been found. Because the hydraulic pump is still in the
warranty period, if it cannot be solved in another week, it can only be
returned for claim. Carl asked the original supplier of each part for the
hydraulic pump and got nothing.

After reading the email, I asked him if the hydraulic pump used a hydraulic
check valve? Carl said that the hydraulic check valve was provided by HAWE
company in the United States, but the after-sales period of the hydraulic check
valve has expired. Because AAK supplied hydraulic check valves to their company
last year, and the quality was very satisfying, although the hydraulic check
valve in this hydraulic pump is not from AAK, he wants to see if AAK technical
team can find out the reason. I said there was no problem with the 8:00 video
conference tomorrow, because the chief engineer of AAK didn't travel, but I'm
not sure if we can help.

The next day in the video conference, their engineers showed the whole system.
Our chief engineer found that the displacement of the hydraulic pump was 8ml /
R, so he asked them to fill the hydraulic pump directly in the oil outlet
pipeline, and then start it up. The hydraulic pump still had no flow. Then
asked them to disassemble the liquid pump to see the oil stains in the inner
cavity of the oil suction pipe in the pump. As a result, there is no oil stain
in the upper half of the suction pipe in the pump and the vertical section,
while there is oil stain in the lower half. The problem should be here. The
lack of flow output of the hydraulic pump is caused by the pump's failure to
suck oil or empty. The problem lies in the hydraulic check valve at the pipe
joint at the oil outlet. It should be that the valve spool of the hydraulic
check valve is stuck. They removed the current hydraulic check valve, and
replaced it with a new hydraulic check valve, and restarted. The hydraulic pump
outputs the flow normally, but it stops working after 5 minutes. Our chief
engineer said calmly that the problem must be here. The reason for the shutdown
is that the new hydraulic check valve does not meet the current working
condition. The new hydraulic check valve must be purchased per this working
condition or re-purchase the previous hydraulic check valve.

Carl asked us to sample 2 hydraulic check valves according to their working
conditions. If they match, this hydraulic check valve will be purchased from
AAK in the future. At the same time, Carl proposed to Denison's senior
management that AAK can be the designated supplier of Denison in the hydraulic
check valve, because they admire AAK's professional ability and strong
technical R & D team. The top management is happy to accept Carl's suggestions
and appreciates Carl's way of solving the problem this time. Carl hopes that
AAK and Denison will become strategic partners and jointly build the world's
strongest manufacturer of hydraulic equipment. We are ready.

AAK hydraulic check valve can replace the local hydraulic valve supplier of
American customer. Its quality is comparable with the international first-line
hydraulic valve brands.You can also have a small try.

https://www.aakindustry.com/info-detai , l/hydraulic-check-valve-aak112

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