Pneumatic Solenoid valve - Selection, use & Arduino command ?

Projects General Guidance
1

Hi all,

Quite new to Arduino, I’m now busy with a transverse project including some pneumatics, which I’m quite unfamiliar with, specially to find the appropriate hardware, hence my call for help !

My project in short: I’m building a test bench for pneumatic mechanical (spring operated) blow off valves: basically, I power a compressor which builds pressure in a chamber where the blow off valve (BOV) is installed. When the pressure in the chamber exceeds the setup pressure of the BOV, this latter opens to release pressure. A pressure sensor installed in the chamber records the max pressure reached before the BOV opening. When the test is finished, I want to be able to flush all residual pressure from inside the circuit and get it back to atmospheric pressure before uninstalling the BOV, installing a new one and starting a new test.

For this last function, I imagine I need to add a pneumatic solenoid valve to the circuit between the compressor and the chamber, operated by the arduino, to open the circuit and flush all pressure.

Here is a quick schematics of how I imagine my setup (black lines are pneumatic lines) :

IMG_1679
IMG_16791944×1434 110 KB

But then I realised that this setup would not remove the pressure in the chamber (if I’m correct ?), only prevent the compressor to add more pressure.

So a second try would give this :

IMG_1680
IMG_16802267×1312 116 KB

Some additional information :

  • Working pressure of the system : between 0,8 bar and 4 bar (absolute)
  • At the beginning of the test (i.e. when the solenoid valve must be operated), pressure in the system is atmospheric pressure (so around 1 bar).
  • Building pressure in the system from atmoshperic pressure to 4 bar (absolute) can take between 1 to 2 minutes.
  • I want to make sure that in case of power outing in the system, the solenoid valve returns to the “open circuit” position. Hence the “Normally open” and “normally closed” outputs of the solenoid valve as on y schematics. This is a fail safe measure to prevent any residual pressure remaining in the system (I will add an emergency button to the
  • 5 VDC or 12 VDC external power sources available
  • Arduino Uno R3 used for command.
  • Short response time may be useful as I may use the valve to flush part of the pressure but not all of it, for a side application (let’s say: open the valve for 0.5s only)
  • In any case, I never need to open the valve or close it at a specific precise pressure. Just the opening time is important.

My questions :

  • First of all: regarding my schematics: am I right in my assumptions ? Is my V2 the correct one to use ?
  • I have no idea how to find a reliable solenoid valve that can fit my needs: any recommendation of manufacturers, models ?
  • Any specific caracteristics I should be looking for when looking for solenoid pneumatic valves ?
  • I am not sure to fully understand how these valves can be commanded by Arduino ?

Any help would be highly appreciated, should you need any additional information, please let me know !

Thanks a lot :slight_smile:

2

That’s okey. Clearly new to Forum too.

Please read and use this link: How to get the best out of this forum - Projects / General Guidance - Arduino Forum

Datasheets for the troubeling devises are requested.

1 Like
3

You also need a second pressure sensor in order to know when releasing the air, the pressure returns to zero. May take a while.

4

That sounds like a lot of work you could accomplish with a three way hand valve.

image
image474×474 36.6 KB

5

When I've done this before to purge condensate in the chamber, we used two separate valves.

6

Thanks for these answers.

That’s exactly the point, I’m looking for a hardware solution, so no datasheet available yet unfortunately :wink:

Pressure measurement side of this project is under control, it’s only with the build of the pneumatic part and the selection of one (or more) solenoid valves (or any other hardware that would help me perform the required task defined above) that I’m looking for support as I’ve no experience at all.

I have the same setup fully manual but I want ti build an automated one (except for the mounting and dismounting of the BOV of course), so this is no solution.

Can you tell me more ?

As said, if there is any better idea on how to perform the required function (keep circuit pressurised when building pressure in the tank and releasing pressure upon arduino command), I’m all in for it. Just really not proficient with pneumatics and solenoid valves so looking for any good outcome here :slight_smile:

7

If you do it with a pressure sensor, when you start save the last value if it is higher then the previous, when the cycle is done you will have the peak within your sample time. The mechanical gauge can be purchased from an industrial supplier.

8

You have not said any thing about the size / volume of the chamber or size of piping / tubing. Post pictures / drawings of your apparatus. Maybe something like this 3 way valve would work.

3 way pneumatic solenoid valve

9

Try this link.

3 way solenoid valve

10

Our scenario was a bit different. We were controlling a standard pneumatic accumulator. So the actuator had its own valve on an air line from the accumulator. Since we were constantly using up air, water would condense out of the air and build up in the reservoir. Periodically we would purge that condensate by blowing it through a separate valve to outside air.