AAK pressure control valve with internal leakage less than 2drops/min

For the leakage in the pilot-operated pressure control valves less than 2drops
/min, Howard from Accupress in Canada, contacted more than 30 Chinese hydraulic
valve manufacturers. Only AAK pilot-operated pressure control valves met the
standard and replaced his local factory in the United States. Last year, the
hydraulic shearing machine they listed sold well. The boss decided to mass
produce it in Suzhou, China. However, the pilot-operated pressure control valve
to be used in the hydraulic shearing machine was originally purchased in the
United States, and the internal leakage is less than 2drops / min. If the
pilot-operated pressure control valve is purchased from China, it will save
money and time. While contacting some old suppliers, Howard is also looking for
new manufacturers of pilot-operated pressure control valves.

We also received Howard's inquiry. The email subject is: can you supply pilot-
operated pressure control valves with internal leakage less than 2drops / min
for our Suzhou factory? We thought it was a domestic purchase, so we politely
refused. Until Howard's second email told us why he wanted to ship to Suzhou,
and he contacted more than 30 Chinese hydraulic valve manufacturers, only two
of them replied that they could try to make samples of pilot-operated pressure
control valves with internal leakage less than 2drops/min, and there was no any
reply from the other manufacturers.

Howard asked if AAK pilot-operated pressure control valves could meet American
factory standards? If not, the sample is meaningless. I told him directly that
AAK had tested samples of pilot-operated pressure control valves with internal
leakage less than 2drops/min for a German company some time ago. The pilot-
operated pressure control valves can be refunded in full if our samples do not
meet the standard. One month later, 30 pilot operated pressure control valves
were sent to Accupress's Suzhou plant.

Four weeks later, Howard sent an email saying that their engineers tested the
pilot operated pressure control valves of AAK and two other manufacturers, and
only AAK samples met the standard. Some parameters were higher than those of
the original American factory, and those of the other two manufacturers did not
meet the standards. In particular, AAK pilot operated pressure control valves
caught up with and surpassed his American factory, which surprised him.

AAK pilot operated pressure control valves can meet such requirements because
of two reasons:

1、For the pilot operated pressure control valves, the matching clearance
accuracy between the valve spool and the valve body directly determines the
internal leakage of the whole valve. AAK has German Nagel precision honing
machine. After honing, the dimensional accuracy of the cone plating of the
valve spool and valve body of the pilot operated pressure control valve is IT7
~ 4, and the surface roughness can reach Ra0.32 ~ 0.04μm, which can not be
achieved by most of hydraulic valve manufacturers.

2、After assembly, AAK uses a special air pressure tester to detect the leakage
of each pilot operated pressure control valve. Within the set pressure and time
range, AAK judges the internal leakage according to the number of bubbles.
However, most factories use the oil pressure test method. As I have known that
there may be no more than three factories that can use special air pressure
test.

Howard told me privately that his boss appreciated his quick finding a supplier
who could replace the pilot operated pressure control valves produced in
American factory. Now his purchasing authority has been improved.

AAK pilot operated pressure control valves, the internal leakage is less than
2drops /min. You are welcome to have a small try!

https://www.aakindustry.com/info-detai , l/pressure-control-valves-aak191

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