AAK hydraulic counterbalance valve, concentricity remained after 1 year

Bill is a purchaser of Manitowoc company in the United States. Two years ago,
AAK received an inquiry about hydraulic counterbalance valves from him, and
there were few contacts later. Unexpectedly, two years later, we received an
email from him consulting about the problems of the hydraulic counterbalance
valves. After communication, we learned that a batch of hydraulic
counterbalance valves he purchased elsewhere had problems and almost got into a
big trouble.

Last summer, a crane shipped by their company, the crane winch system lost
control during construction and the hook slipped off. Fortunately, there was no
one under the hook at that time, otherwise there would be great trouble.
According to the analysis of the field engineer, it is considered that the
hydraulic counterbalance valve used in the crane winch system is abnormal.
After disassembling the hydraulic counterbalance valve, it is found that there
is a deviation in the concentricity between the valve spool and the valve seat.
The valve spool is affected by large eccentric hydraulic force, so that the
hydraulic counterbalance valve lost its function of balance and the hook
slipped off.

After knowing the reason, Bill contacted the original hydraulic counterbalance
valve supplier. The supplier replied that the hydraulic counterbalance valves
were indeed within the warranty period, he can replace the abnormal hydraulic
counterbalance valves with a new ones, but can not guarantee that each
hydraulic counterbalance valve had the same concentricity and could be used for
more than 1 year. Bill was worried about the stability of the new hydraulic
counterbalance valves. He didn't want to have big trouble and had to find a new
hydraulic counterbalance valve manufacturer.

In crane hydraulic system, the performance of hydraulic counterbalance valve is
the cornerstone of winch system, and the consistency of hydraulic
counterbalance valve concentricity is the key. Bill also asked other hydraulic
counterbalance valve manufacturers. No factory guarantees that the
concentricity of the hydraulic counterbalance valve can be still consistent
after 1 year of use. Bill wants to know how about the concentricity of AAK
hydraulic counterbalance valves after being used for 1 year.

We told Bill that perhaps having a try is the best answer. He can detect the
concentricity of AAK hydraulic counterbalance valves in an all-round way. After
15 days, we sent 4 samples of hydraulic counterbalance valves according to his
drawings. Seven days later, Bill informed us that the concentricity test data
of AAK hydraulic counterbalance valves were indeed more comprehensive than that
of his original manufacturer. How to ensure that the concentricity of AAK
hydraulic counterbalance valves is still consistent after 1 year of use?

For some manufacturers, when processing the components of hydraulic
counterbalance valves, there are discrepancies between the specification
parameters and design, the standard of normal distribution cannot be reached,
there are certain differences in between the structure of components and the
concentricity of grooves, which is difficult to detect. AAK has Mahr
cylindricity instrument imported from Germany. Through EasyForm software, it
can measure each part accurately and quickly, and obtain the measurement
results. With the help of computer, the work piece can be quickly adjusted and
aligned to improve the measurement efficiency, ensuring the concentricity of
each hydraulic counterbalance valve is 100% consistent to reduce wear.

More than half a year later, Bill sent an email saying that another two
hydraulic valve manufacturers that he recognized, also provided samples of
hydraulic counterbalance valves with AAK together last time. All the hydraulic
counterbalance valves were retested after 6 months of use. It was found that
the concentricity of the hydraulic counterbalance valves from another two
manufacturers changed compared with the data before use, but the concentricity
of AAK hydraulic counterbalance valves did not change. The boss asked him to
list AAK as the most trusted supplier for their hydraulic counterbalance
valves.

AAK hydraulic counterbalance valves, are sophisticatedly inspected, can be used
without no trouble. You are welcome to have a small try!

https://www.aakindustry.com/info-detai , l/hydraulic-counterbalance-valves-aak154

Click to Enlarge