After adding PTFE retaining ring, AAK hydraulic check valve does not leak

Last week, Eddy emailed me that after AAK hydraulic check valves of the test
order has been used for 3 months , the O-ring seal was still free of wear. He
was finally relieved. Eddy, who works at Terex company in the United States,
has successfully purchased hydraulic valves from China over the years, and his
boss is also very satisfied. At the beginning of last year, a customer
complained about the hydraulic equipment supplied by their company for offshore
oil field exploitation, which made him very passive. Some equipment has the
phenomenon that the drilling machine rises slowly or cannot rise. Their
engineer found that the hydraulic check valves used in the oil circuit of the
hydraulic equipment had internal leakage, the one-way oil circuit could not be
fully locked, resulting in the inability of the equipment to rise. Their
engineer can only replace the hydraulic check valves with the previous spare
ones and bring the problematic hydraulic check valves back to the company. Eddy
sent these hydraulic check valves to the original supplier. The supplier
replied that the reason for the leakage in the hydraulic check valves was that
the ambient temperature was too low. The O-ring seal of the hydraulic check
valves was hardened and worn quickly in extremely cold conditions, which was
difficult to solve. Eddy knows that if he can't give reply to customer like
this, he must find a manufacturer who is able to produce the hydraulic check
valves working at low temperature. Eddy contacted several hydraulic check valve
manufacturers, most of them reported that it was difficult to achieve 100%
leakage free under such extremely cold conditions. Eddy was worried.

When Eddy contacted us, our engineer wanted to see the real reason for the wear
of the O-ring of his hydraulic check valves and asked him to send the defective
hydraulic check valves. After receiving the samples, our engineer realized that
even if the cold resistant O-ring is used, it may not be 100% leak free, and
the structure of the sealing ring needs to be changed, because the internal
structure of this hydraulic check valve is a little complex. Eddy said that
this is the only different reply he received. It seems that Eddy still doesn't
believe that AAK can solve the leakage problem of the hydraulic check valves.

I told him that a Russian customer has purchased hydraulic relief valves from
us, and their hydraulic equipment is also used in oil fields. The customer told
us that under extremely cold conditions, the service life of AAK hydraulic
relief valve is more than 4 times that of its peers. Three weeks later, we sent
4 pieces of hydraulic check valves of the test order to Eddy. There was no news
after 3 months. Until last week, we received email from Eddy amazing that their
engineers also admired our idea of adding retaining ring to the O-ring of the
hydraulic check valves.

I told Eddy that the installation of retaining ring can play the role of axial
fixation, reduce the gap between the O-ring and the low-pressure side of the
seal, and prevent the O-ring from being 'extruded'. At the same time, the
structure of O-ring added with retaining ring will bear much greater pressure
than when the O-ring is used alone, which reduces the wear of the O-ring.
Moreover, AAK uses PTFE retaining rings that can withstand extremely low
temperature and can be used for almost all media without hardening and damage.
The most important thing is that AAK engineers can design and manufacture with
strict tolerance according to the working conditions of their hydraulic check
valves. That is, not only the material is good, but also the structure needs to
be matched, but also the strict tolerance manufacturing during processing.

In the hydraulic check valves, the quality of every part is related to the
durability of the whole valve, including the small retaining ring. AAK can
design and customize the hydraulic check valves according to the actual working
conditions of customers. The hydraulic check valves with PTFE retaining ring
can be used in extremely cold areas and ensure durability.

AAK hydraulic check valves, has unique tips on designing the retaining ring,
welcome to have a small try!

https://www.aakindustry.com/info-detai , l/hydraulic-check-valves-aak158

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