Draw A 5/3 Air Valve
Drawing a 5/3 air valve can be a bit tricky. If you haven't already done so, take a few minutes to look at the other pages on this site about drawing air valves, starting with drawing the 2-2 air valve. These pages are:
If you have reviewed all these pages and understand how to draw all the valves up to a 4/2 or a 5/2, then drawing the 5/3 or the 4/3 will not be too complex for you, I hope.
A valve schematics purpose is to show all of the possible positions for that one air valve, to allow the system designer to insert a particular valve into an air circuit diagram, and to show system builders the condition of that valve when it is at rest in the circuit. It will also show the valve actuators necessary for each air valve in that circuit.
On the page "drawing the 5/2 air valve", the final schematic for the 5/2 was as shown in Fig. 53.
Fig. 53 shows both positions of this 5/2 valve and the corresponding flow paths, depending on that valve position. You can see how the flow paths change whether it is the right side or the left side of the valve that is currently in control.
The first number in a valve designation, in this case a five, indicates that this valve will have five ports. The second number indicates the number of positions for that valve, so a 5/3 valve will have three positions, not two as shown in Fig. 53. Where and how does that third position get drawn? Please see Fig. 55, below.
In the three position valve schematic, we split the 5/2 valve schematic in half, and add a space in the center. This is where we will add the flow paths predicated on the type of 5/3 valve this is.
I do note that splitting the schematic is a whole lot easier done with a computer graphic. This is why, when drawing valves with pencil and graph paper, a good eraser is essential. Be optimistic! As you get comfortable with drawing different styles of valves, fewer errors will occur and you will have to correct fewer mistakes.
On this page that discusses 5/3 and 4/3 valves it is noted that the third position in a 5/3 valve is a center position. The air control mechanism inside 5/3 valve (usually a spool of some sort) is shifted into the center position inside the valve by one of two internal spring actuators. There is a spring located inside the valve at each end of the internal spool. When no external valve actuator is being exerted on the valve these springs center the spool into the valve's third position.
The internal valve spool might have - O - rings installed on it. It might have a bonded Buna-rubber surface, it might be all aluminum or plastic and slide back and forth inside a tube packed with "O" ring type seals, or it might be a high tolerance, machined metal-to-metal spool.
Each spool style have their benefits and their negatives. Each type might be made by a different manufacturer, and they will attest to the superiority of their design over every other valve manufacturer's, of course.
Three Configurations
The third position in a three position valve can be one of the following:- Blocked Center
- Open Center
- Pressure Center
These flow path options may not be available from all valve manufacturers so if you are looking for a specific type of 5/3 valve, you may have to shop around.
In order to complete the schematic for our 5/3 compressed air valve, we have to determine which of these three configurations we need for our valve, and insert the schematic for that flow path between the other two positions.
Here are the schematics for the three positions:
There is more on drawing the 5/3 air valve right here...
