Need explanation for pneumatic valve

Adenitz

Member
Join Date
Feb 2010
Location
tir
Posts
41
Hello automation experts,

I kindly ask your help about the pneumatic valve shown in the attached image.
The valve is 3/2 which means it should have 3 ports in total and only two possible ways of air directions, but in the manufacturer's catalog and on the valve, there are four holes. Can you please explain me what are ports 1, 2 and 3 on the drawing?

If possible, can you please write me port numbers on A, B C and D that are shown in the image?
It looks like to me that D = 1, A = 3 and C = 2????

Thank you!

Symbol.png
 
This is a pilot valve for a larger valve actuator.

Supply would be via Port A. Port B and C would be open and close on the actuator. Port D is the vent.

Open / close depends on the actuator. You'll notice the O-rings around ports B and C. The pilot valve fixes directly to the actuator so these o-rings seal between the actuator and the pilot. The orientation affects whether its actuator is normally open or normally closed when the pilot is powered.
 
I sort of disagree with that, It looks like the valve is a type that can be banked therefore the two ports on the side are the supply & exhaust otherwise you would have to pipe a bank of valves individually. This looks like something I used many years ago, the valves were bolted together side by side so the common supply & exhaust were at the side & the ports at the top (or bottom).
I have searched but not found one of those in your pic, it seems that that type was dropped in favour of manifold connections where the supply & exhaust was at the bottom & the drive ports at the top. The way to tell is if the ports on the side have grooves for "O" rings but the ports at the top do not then the side ones are as stated above.
In that case B&C are the supply/Exhaust & A & D are the drive ports, this makes more sense. To use it as a one off valve, the supply side will need to be blanked at the other side (this is assuming that on the opposite face also has two ports). However, as I cannot see the other side I cannot be sure if those ports go strait through.
 
Last edited:
first of all you have a schematic that does not match your picture(one has numbered ports the other has letters for ports), the schematic shows valve in spring returned position or de-energized position. Port 1 would be pressure(currently blocked) and port 2 would be cylinder or what every device your driving, port 3 exhaust for port 2 thats in the position shifted to left or again spring returned/de-energized position.
If you energize or shift to right you then connect port 1 to port 2 and port 3 is now blocked so you activate what ever device, when you de-energize again you block port 1 and port 2 is allowed to exhaust through port 3.
I have no way of know about port a,b,c,d in picture but what I said above is from the schematic representation of the valve.

This would be called a three way valve, three ports one pressure, one exhaust and one cylinder or what you are driving. I could see that this might be used to bolt to an actuator, thus working like i described, I have seen these used on larger linear actuators that control valves.
 
I might add that if you put pressure on port a in de-energized position and no air comes out that would be port 1 and then port "d" would be exhaust or port 3
 
I sort of disagree with that, It looks like the valve is a type that can be banked therefore the two ports on the side are the supply & exhaust otherwise you would have to pipe a bank of valves individually.

It might be as you say, what made me lean towards the individual valve is the M6 holding screws through the side. It would not be a great bank design if you had to disassemble every valve to the RHS to replace the one on the far left. The ones from Burkert that we commonly use just slot into a manifold. The supply and exhaust ports are on the back.

If the OP could provide a part # that would help a lot!
 
Yes, I dont know for sure, the first question would be do the ports b and c go through valve body? if so then what i said is probably not the case and it is a manifolded valve however the schematic representation is as i said. if it is a manifolded valve then it is for a single acting cylinder or in other words a cylinder powered one way and spring returned or yet another valve is used to create a 4 way, because a 4 way is require for a double acting cylinder and a 3 way for a single acting cylinder. I have replace several of these,(no ports on other side) they were bolted on to a linear actuator, but again without seeing other side not 100 percent sure.
 

Similar Topics

Hello all, A little background. Our organization is exploring using the Siemens S7 1500 PLCs in the future. We are an Allen Bradley's house...
Replies
16
Views
1,883
Dear atomation experts, Can you please help me by explaining how spool valve with the attached symbol works? I know that spring (b) returns the...
Replies
5
Views
1,947
Hi. Im having problems understanding hw and gsd files. Hw is the hardware itself and gsd is what? What about installing hw files from siemens...
Replies
8
Views
2,335
I am newbie in S7 and PLC and i am trying to learn analog processing in S7. I have got an example, which raise some questions. In the following...
Replies
5
Views
6,764
Hi guys, in literature I found term "tripping". I dont know what is it but I know it has something to do with circuit breakers. For example...
Replies
8
Views
3,355
Back
Top Bottom