After replacing with AAK hydraulic valve block and O-ring, the hydraulic equipment does not leak oil

Kayden, from AH Garner company in the UK, has successfully purchased hydraulic valve blocks in Ningbo in recent years, and has cooperated with AAK on some high requirements hydraulic valve blocks for many years. He sent an email at the end of last year: I need AAK’s help. After communication, we learned that a new hydraulic equipment of their company was complained by customers about oil leakage in about 3 months. After inspection, their after-sales personnel found that when the equipment is switched with high-speed and high-frequency action under high pressure, the small O-ring of the cover plate of the hydraulic valve block is prone to oil leakage. The engineer asked Kayden to find the original supplier to replace the hydraulic valve blocks or cartridge valves. Unfortunately, Kayden purchased the hydraulic valve blocks and threaded cartridge valves from two factories. The manufacturer of the hydraulic valve blocks replied that the thread size accuracy of the cartridge valves did not meet the standard and caused oil leakage, while the cartridge valve manufacturer said that the accuracy of the hydraulic valve blocks did not meet the standard.

The hydraulic valve blocks and cartridge valves have passed the inspection. How can there be a problem as soon as they are assembled on the equipment? Kayden suspected that the design of the hydraulic valve block was flawed, but the engineer thought the design drawing was in line with the principle. The customer didn't receive the solution, and complained to the boss, who asked Kayden to completely solve the oil leakage problem of the hydraulic valve blocks within 30 days. Now Kayden was stumped and didn't have a clue.

I asked Kayden to send us the drawings of the hydraulic valve block and cartridge valve, and system principles. AAK engineers found no problems after analysis. Our engineer asked Kayden to provide the video after the equipment was started up. Combined with the system schematic diagram and equipment fault video, our engineer judged that the position of installing O-ring at the interface of hydraulic valve block and cartridge valve was inappropriate. If the position of the O-ring is lowered, and the cover plate O-ring is completely free of oil, install and fasten the cartridge valve cover plate, and produce the hydraulic valve block and cartridge valve in a same factory, the oil leakage problem of the hydraulic valve block may be solved completely. Kayden seems to have seen the dawn and asked AAK to make samples.

After 25 days, AAK sent out the integrated hydraulic valve block sample. A few days ago, Kayden emailed us that it has been 3 months since the hydraulic valve block was replaced with AAK samples, the equipment works normally without oil leakage. Kayden told me that AH Garner engineer admired AAK’s strictness in details. It is so obvious, why didn't he find such an obvious problem?

In order to make sure that the integrated hydraulic valve block is 100% free of oil leakage, it is not only necessary to be strict on the position of the O-ring, but also the installation of the O-ring on the hydraulic valve block. On the premise of ensuring the reasonable compression of the O-ring, it is necessary to avoid oil in the annular sealing surface of the O-ring, and any displacement of the O-ring will be in an oil-free lubrication state, so as to improve the displacement resistance.

Kayden privately told us that the boss praised his quick and thorough solution to the problem, and asked him to purchase integrated hydraulic valve blocks from AAK in the future.

AAK hydraulic valve blocks, be strict in every detail, you are welcome to have a small try.

AAK HYDRAULIC VALVES (209) 2022-04-27