AAK Hydraulic Directional Control Valve Strengthened Spool Long Life

Blade is from Canada. He has been purchasing hydraulic components successfully
for 3 years. Unexpectedly, a hydraulic cartridge directional control valve
stumped him. In the second half of last year, a batch of their hydraulic
logistics lifts were complained by customers, some of them were unable to work,
probably because the hydraulic cartridge directional control valve leaked.
After checking, it was found that the valve spool was deformed. The original
manufacturer of the hydraulic cartridge directional control valves said that it
had been shipped for 9 months, and some exceptions were inevitable. It is
possible that the internal stress of the valve spool was not eliminated in time
during the heat treatment process, resulting in deformation or cracking of the
valve spool. However, there are more and more complaints later. Blade realized
that the service life of the hydraulic cartridge directional control valves
from the original cartridge valve manufacturer may be about 1 year. He had to
find a new hydraulic cartridge directional control valve manufacturer with a
service life of 2 years. A week has passed, and no one can guarantee a 2-year
life span.

Blade found AAK when browsing Google. He noticed that AAK was continuously
supplying HydraForce, and left a message: Can AAK ensure that each hydraulic
cartridge directional control valve spool is free of deformation or cracking
within 2 years? I guess he encountered trouble in purchasing hydraulic
cartridge directional control valves. After communication, I learned the above
information. I replied that the life expectancy of 2 years should not be a big
problem. Blade sent the drawing of the hydraulic cartridge directional control
valve and asked for the lead time for 10 samples. After 45 days, AAK sent the
samples of the hydraulic cartridge directional control valves, but there was no
email from him after that.

Last week, Blade suddenly sent an email, and it was a PO for 600 hydraulic
cartridge directional control valves. It can be seen that the samples of AAK
hydraulic cartridge directional control valve was approved by his customer. The
valve spool is the key to long service life of this hydraulic cartridge
directional control valve.

1. AAK select 20CrMo material to produce the valve spool. After quenching and
tempering, the materials are more conducive to processing. Most hydraulic
cartridge valve manufacturers ignore this action.

2. 0.25~0.35mm machining allowance shall be reserved for rough turning, then
carburizing, quenching and high temperature tempering shall be carried out, and
then the valve spool shall be subject to low temperature cold treatment. The
surface hardness of such valve spool is above HRC63, and the residual austenite
in the internal structure is eliminated.

3. The valve spool shall be subject to semi finishing, and 0.1-0.15mm allowance
shall be reserved during the process, and then the valve spool shall be subject
to tempering treatment. The temperature of tempering treatment shall be 320°C,
and the temperature shall be kept for 5 hours, which can eliminate the residual
internal stress and greatly improve its stability. After tempering the valve
spool, the honing machine shall be used for finishing to ensure the accuracy
and ensure that each valve spool meets the standard.

AAK hydraulic cartridge directional control valve, the valve spool is processed
specially, you can also try a small order!

https://www.aakindustry.com/info-det , ail/directional-control-valves-aak439

Click to Enlarge