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The Easiest Way to Design With 4-Way Directional Control Valves.

We really should re-name HydroSym, our software package for quick and easy hydraulic design, to "HydroSym, hydraulic schematics, your way!"

In the latest update on HydroSym we revealed a new flexibility for your hydraulic design needs. This time it is in the form of freedom to design with four way directional control valves with complete flexibility on the naming sequence of the ports.

Why did we do this? Well, first and foremost, this is a feature our users have asked for. Secondly, we believe it is important to make it as easy as possible for hydraulic engineers to choose and design easily with hydraulic parts of any brand. This way your hydraulic software works for you, and you choose the part that fits your design best regardless of the brand.  

In hydraulics there is not a set rule on the sequence of ports in a four way directional control valve and it is possible to come across different manufacturers using a different naming sequence. For example, the most standard one you can come across is P - A - B - T. But as you know, it is not the only way you can see it on a schematic.  

4 Way Directional Control Valve

But first, let's do a quick review:

"The 4-Way Directional Control Valve is a directional control valve that has four ports and three positions, or flow paths. The ports connect to what in a typical model are a hydraulic pump (port P), a storage tank (port T), and a double-acting actuator (ports A and B). Fluid can flow from the pump to the actuator via path P-A or P-B and from the actuator to the tank via path A-T or B-T—depending on the working side of the actuator." (Matlab)

P - A - B - T Example

Probably most common way to denote the sequence is: P - A - B - T 

We see a good example of that with these sandwich check valves from a Bosch Rexroth datasheet. 

But this is not the only way to arrange the diagram.  

Now let's take a look at a few other variations that you can come across.  

P - T - B - A Example

In the tech-sheet of Sun Hydraulics sandwich valve body, EB2, we see the sequence as P - T - B - A 

Here is another example of a Wandfluh sandwich flow control valve. 

A - P - T - B Example

Here we see the sequence as A - P - T - B 

All 3 ways with HydroSym

With HydroSym you can easily click and add any part you want to use from the extensive Paro Library of over 40K hydraulic parts, and in this case it does not matter how the manufacturer chooses to sequence the ports you can add them to your diagram as they are, and carry-on! Here we did a quick schematic to show you all three ways, with both top and bottom configurations. 

Do you have a preferred way to sequence ports?  Is there a specific reason for it? Let us know in the comments.  

Try it yourself

To try out HydroSym software and see how it can work for you, we invite you to a one month free trial. Request it here.