1. “Obedient” control performance: function ≠ performance!
What is the core task of hydraulic valves? It is not “being able to adjust pressure”, but “adjusting steadily and accurately”!
For example: the same pressure regulating valve, some valves have very good data in the laboratory, but when installed on the equipment, the pressure fluctuation is as large as an electrocardiogram, which is a typical “function meets the standard, performance is poor”. A real “good valve” must not only achieve basic functions but also continue to be stable under transient conditions (such as sudden start and stop, load mutation).
When a German research institute developed a ceramic slide valve, it even directly changed the cylindrical valve core into a rectangular one to avoid processing difficulties – solving the problem is the kingly way, no matter how good the structure is, it is useless if the performance is not good!
2. The instrument can withstand “high pressure attack”: pressure resistance is not just for show!
Modern hydraulic systems are often “pressure roller coasters”, and the instantaneous impact pressure may soar to 125% of the rated value! At this time, if the valve can’t bear it, it will leak oil at the least or burst at the worst.
But the real pressure resistance test is still to come – after the high pressure disappears, the performance must be restored to its original state! Some valves barely pass the high-pressure test, but as soon as they return to normal pressure, the sealing is directly scrapped. Therefore, the standard of a good valve is only one: it can withstand high pressure and will not leak after the pressure is reduced!
3. Long life ≠ blindly stacking materials! Durability depends on the scene
The life requirement of the hydraulic valve depends entirely on who it is used with:
Valves on missiles: only need to work for tens of minutes and then stop working after the explosion.
Wind power hydraulic valves: must withstand 20 years of wind and sun.
Underground valves in coal mines: explosion-proof and corrosion-resistant are just needed.
Durability is not about mindlessly stacking materials but about using them in the right place. For example, the friction speed of the valve core is much slower than that of the pump, so the life of the valve is usually not a big problem. But if it is a high-frequency action valve in the metallurgical industry, ceramic coating or special heat treatment process must be used.
4. Stability: How many parts can break out of a million?
What do OEMs fear the most? Eight out of ten valves in the same batch have performance fluctuations! Stability does not rely on “full factory inspection” but on management from the source.
Nowadays, international manufacturers have long regarded ISO 9001 and IATF 16949 as standard, and all five core tools (APQP, PPAP, FMEA, MSA, SPC) are used. Domestic OEMs improve quality control according to the German VDA 6.3 standard, and their stability can also be in line with international standards.
5. Reliability: Don’t let a valve ruin a machine!
Reliability is a double test of “design + manufacturing”:
Design: performance decays slowly, and it can still be used after wear.
Manufacturing: a failure rate of one in a million is considered qualified (for example, mean time to dangerous failure MTTFd> 30 years).
Why are imported valves expensive? Because users calculate the loss of downtime – the money for replacing the valve is a small part, and the loss of hundreds of thousands of yuan for a day of equipment downtime is painful! If domestic valves want to make a comeback, low prices alone are not enough, “reliability” is the hard currency!
6. Price: Is cost-effectiveness a “false proposition”?
The hydraulic valve market is divided into OEM pre-market and after-market replacement parts:
Pre-market: OEMs want “large quantity, stable quality, and slow payment”.
After-market: Users want “cheap, repairable, and fast delivery”.
But price wars are a double-edged sword! Domestic valves rely on imitation of lower prices, resulting in thin profits that make it impossible to conduct research and development, and after-sales service is even more of a “one-time deal”. On the other hand, imported valves are expensive, but they are expensive because they are “worry-free”
There is no absolute good or bad in hydraulic valves, only whether they are suitable or not. Next time when you choose a valve, don’t just look at the brand and price, ask yourself three questions first:
1. What performance does my equipment need?
2. How long can this valve be used? How much loss will it cause if it breaks?
3. Does the supplier understand my application scenario?
If you understand these, you can strive to maximize the role of the valve!
