Most of you reading this know the common benefits of hydraulic cartridge valves (click here for an excellent refresher). However, there are several key benefits routinely overlooked or misunderstood throughout the industry. HydraForce has dedicated significant efforts to innovation in cartridge valve technology — including the consolidation of multiple valve functions into a single cartridge, higher pressure and flow ratings, and improved machine control solutions. |
 |
Most of you reading this know the common benefits of hydraulic cartridge valves (click here for an excellent refresher). However, there are several key benefits routinely overlooked or misunderstood throughout the industry. HydraForce has dedicated significant efforts to innovation in cartridge valve technology — including the consolidation of multiple valve functions into a single cartridge, higher pressure and flow ratings, and improved machine control solutions.
Now, let’s talk about the benefits that go along with these improvements:
1. Performance
Traditionally, directional control functions were not considered a strong suit of cartridge valves. When searching online for a supplier of Directional Control Valves, a Google search will scarcely yield a "Cartridge Valve" return in the results. This has mostly to do with the limited flow capabilities of early cartridge valves. However, a lot has changed over the years, and today’s market could not be more ripe with Directional / Stack valve alternatives.
The bridge circuit below (named for its hydraulic similarities to the electronic "Wheatstone Bridge") has several key attributes which make it ideal for directional control. For starters, by having individual cartridge valves at the inlet of your A and B ports you get the distinct advantage of both meter-in and meter-out capabilities. Another advantage of this circuit is the ability to scale the appropriate cartridge valves for optimal flow. Other benefits include low-leakage poppet-type valving, lighter housing weight and the ability to achieve float or motor functions.
View/Download Directional Bridge Circuit graphic as:
PDF file (127 KB) | DXF file (201 KB)
HydraForce i-Design HF3D file (zipped 29 KB)
While we can’t deny there are inherent advantages of traditional directional stack valves, there are good reasons to consider this cartridge-valve alternative when designing your machine.
2. Customization:
An issue very near-and-dear to many OEMs' hearts is customization. The beauty of cartridge valves is that the packaging is completely, 100% customizable. It’s so customizable in fact, that we’ve developed iDesign to aid you in the specification process.
Customization allows you to design lighter, more compact valve packages that can be mounted where they will be less susceptible to external damage. Also, keep in mind that elimination of external piping and plumbing can save you money on material and assembly time. The valve package arrives fully assembled and tested. Simply mount the package on the machine, connect it, bleed it, and the system is ready to run. Think about that the next time you are staring at a catalog of mass-produced mono-blocks, you could be telling us exactly what you want, instead of taking what is offered (and potentially paying for features you won’t use).
3. Serviceability:
At least once a month a customer will ship us an entire manifold block because a relief valve wasn’t functioning properly or a solenoid valve wouldn’t actuate. Unfortunately, doing this completely negates one of the major benefits of an integrated circuit. Cartridge valves are designed to be removed and replaced quickly without disturbing any external plumbing. Consider this the next time you un-plumb and ship an entire manifold rather than the problem valve. For the cost of the shipping charges on the "failed" block alone, you could just as easily order the appropriate MRO parts.
Another common scenario has a customer requesting a bank of sandwich valves for a block with multiple low-flow directional functions. Some customers say that they like the serviceability and modularity of a sandwich configuration. Well folks, I'm here to tell you, it doesn't get more serviceable or modular than a cartridge valve manifold. Simply turn off the pump, make sure that any stored energy in accumulators has been released, unscrew the problem valve, replace it with an operational valve and you’re back in business! (For tips on troubleshooting, look at this.) And just for the record, in the circuit above, you wouldn’t want to remove a counterbalance valve with the load being held up in the air ;-)
In conclusion, these benefits are merely the tip of the iceberg. The performance benefits, flexibility, and customization potential of today’s cartridge valve technology are too numerous to list here. But, we hope we have given you enough reason to give cartridge valves a second look.
About the Author:
David Price oversees training and marketing communication efforts at HydraForce Inc. Contact David
