AAK hydraulic directional control valve adjusted integrated design

One morning last month, Antonio emailed us that there was a problem with AAK
hydraulic directional control valves purchased some time ago, and a problem was
found in the factory commissioning of the bending machine. The starting
pressure of the hydraulic system of the bending machine will suddenly increase.
Their engineers think it is caused by the instability of the hydraulic
direction control valves and ask us to replace it. I'm totally confused.
Because this hydraulic directional control valve is produced and inspected in
full accordance with the parameters provided by Antonio, and the parameters of
the hydraulic directional control valve are approved in the commissioning stage
of the bending machine.

Antonio is from Prada Nargesa company in Spain. He has cooperated with AAK on
hydraulic directional control valves for several years. This is the first
complaint from him. In the sample stage, Antonio informed that this hydraulic
direction control valve was used in the hydraulic system of the bending machine
produced by his company. It was noted that the bending tonnage was required to
be 400 tons, the maximum bending length was 6 meters, and the bending accuracy
was +/- 0.3°. The pressure and accuracy requirements of the hydraulic
direction control valve were very high. After our internal discussion, we found
the problem strange.

AAK engineer asked Antonio to send a video of the working condition of the
hydraulic system of the bending machine for us to check what the problem is.
Through the video, we found that there was a problem about the installation
position of the needle valve of the integrated valve block of the hydraulic
system and the position of the hydraulic directional control valve. It was
preliminarily judged that the pressure regulation mode of the hydraulic system
of the bending machine is not correctly designed, and this hidden danger will
come out after more than 8 hours of continuous test run. But the designers of
their company didn't agree with our proposal and thought we were shifting the
responsibility.

I suggest Antonio give us 30 days to redesign the integrated valve block. If
there are still problems after installation, AAK is willing to bear all costs.
Considering that these bending machines are in a hurry to ship, it will take
longer time if purchasing new hydraulic directional control valves, moreover it
is not guaranteed that the new hydraulic directional control valves will be no
problem, Antonio reluctantly agreed with AAK proposal. After 25 days, AAK sent
out the integrated valve block with hydraulic directional control valve, which
was installed and debugged for more than 8 hours. Everything of the bending
machine was normal, and their designers had to affirm it.

AAK professional engineers designed the pressure regulation of the hydraulic
system of the bending machine as a modular type, and rearranged the position of
the needle valve and the hydraulic direction control valve, so as to provide
the proportional regulation function. At the same time, the unloading circuit
is simple and reliable. The safety pressure valve is connected in parallel in
the lower chamber of the oil cylinder to form a double safety circuit to
prevent the abnormal rise of the oil pressure in the lower chamber from
damaging the oil cylinder and pipeline, so as to ensure the safety of the
equipment.

Antonio told us privately that a similar situation happened the year before
last. The hidden danger of the original design of the equipment is simply
considered to be the problem of the supplier's hydraulic directional control
valve. Even they changed 3 manufacturers of hydraulic directional control
valves, problem was still not solved.

AAK hydraulic directional control valve can give technical support that peers
can't give. You are welcome to have a try!

https://www.aakindustry.com/info-detai , l/hydraulic-directional-control-valves-
aak180

Click to Enlarge