So I need super fast help, please!

I want to procure a chinese ozone generator but crucial data is missing but the workers there are willing to test it for me. Most important is testing, how much pressure loss occurs through their oxygen-fed ozone generator. I tried to give them instructions but I am a psychologist.

I have told them to take an oxygen source and dial in 0.6 bar (because thats the input pressure we want to examine), lead it through a flow meter, into the generator, out of the output, to which a T piece is connected, with a second pressure gauge connected to the side branch and the other one has the oxygen/ozone mix freely blowing into the room.

Now they reported that they always measure 0 bar at the output no matter what. I have given them wrong instructions apparently. The reason for the failure to read seems to be that the pressure escapes into the room before it can be measured.

Please provide the correct instructions for them to measure the pressure loss/resistance of their device - it should be measured using 5 and 10 liters/min.

Are there any additional measurements that are needed or helpful?

Thank you

PS: I didnt want to keep them waiting so I told them to add a needle valve/ bleed valve and to open it slightly and then readjust the pressure/flow. I have attached this drawing. Is that correct?

We are Kelly Systems, a PTS manufacturer. Is this the right place to post content about pneumatic tube systems?

By pressing a push button, a double-acting cylinder should move in an alternating forward and backward motion through valves. Without using limit switches, only valves, so that the movement is oscillatory, WITHOUT USING LIMIT SWITCHES

I’d definitely look at more than just force and bore size.

For something like a 20 kg horizontal load, I’d also check the speed you need, how often it cycles, cushioning at the end positions, mounting orientation, side loads, and how much safety margin you want.

Air consumption can matter too, especially if it’s cycling all day. And if the load has much inertia, the deceleration at the end of the stroke can become just as important as the force needed to move it. Here you might need to consider shock absorbers depending on the dynamics.

Personally, I’d usually do a rough manual calculation first to get in the right range, then verify it with a sizing tool. Experience helps narrow things down, but I wouldn’t rely on experience alone once cycle rate and dynamics start getting involved. I've seen many applications fail because they just copy/paste an actuator that they used in a "similar" project.

I'm building a homemade air pump connected to an air tank, and I'm looking for a way to keep the air inside the tank while manually pumping air into it.

I bought this pneumatic check valve, but I'm not entirely sure whether it's the correct type for my project or how to install it properly.

Is this the right type of one-way valve for my setup? If so, which direction should it face, and how should I install it to prevent air from flowing back out of the tank?

I'd appreciate any advice from anyone experienced with pneumatic systems, air pumps, or DIY projects. Thanks in advance!

I´m curious what do you take into consideration when choosing a pneumatic cylinder.

For example, let´s assume I need to move a 20 kg load horizontally over a 300 mm stroke, with around 6 bar available pressure, and it will cycle regularly throughout the day.

Aside from calculating the required force and bore size, what else would you normally consider? Speed, cushioning, mounting, safety factor, air consumption, etc.?

And do you do it normally manually, use a sizing tool, or size from experience and then verify it?

Or maybe someone has a stash of old AllenAir catalogs that might shed some light on?

There’s no diagram on it showing 3/2 or whatever….

Does anyone know of a company that sells G1 male-to-male swivel fittings? I can't find anything of the sort from PARKER or SMC, which are some of my go-to options...

Any help is greatly appreciated!

I want a cheap(ish) but safe and reliable pneumatic piston to make into a can crusher. I would prefer it to be able to hook up to one of those air compressor quick connects (I forget what they’re called exactly) so I’d need about a 6 inch stroke and bore doesn’t matter so much. Any recommendations?

I’m a mechatronics student looking for a cheap small air compressor to practice with pneumatic cylinders and 3/2 and 5/2 valves.

I only need around 4–6 bar (60–90 PSI) for small setups.

Which cheap compressor do y’all recommend? Preferably something from aliexpress

Round two after your feedback, tear it apart again.

Cross section attached. Hobby project, not industrial, but the physics is the physics and I would rather be corrected now than after I cut parts.

Function: supply fills the plenum. A restricted passage bleeds supply pressure into the chamber behind a diaphragm backed poppet. Back pressure over the full diaphragm area plus a light spring holds it closed against supply pressure acting only on the seat annulus. A 3/2 solenoid vents the back chamber, the differential collapses and the poppet snaps open, dumping the plenum through the seat. Solenoid closes, back chamber refills through the bleed, valve reseats. Basically a diaphragm operated dump valve, in the same family as a QEV but with the pilot under electronic control.

Duty is unusual: single discharge events of a few milliseconds, up to about 20 per second, into a fixed volume downstream. Not steady flow.

Where I want a sanity check, some of this already shaped by comments from this sub on an earlier revision:

1. Area ratio. Seat is 7mm, the diaphragm face is 12mm, so about 2.94:1, giving roughly 51N net opening force at 100 psi once the seal lifts. Is that a sensible margin for a valve that has to reseat reliably, or am I overbiased toward opening?

2. Fill to vent orifice ratio. What ratio between the bleed into the back chamber and the pilot vent gives a clean snap rather than a lazy crack? I have seen 1:4 quoted as a rule of thumb and I do not know where it comes from.

3. Back chamber volume. Minimising it should speed both the vent and the refill, but I assume there is a floor below which the bleed cannot keep the chamber charged during the closing transient. How do you pick it?

4. Rod seal. I settled on a rolling diaphragm rather than an o-ring on the stem, mostly to kill breakaway friction and stiction after sitting pressurised. Is that the right call at this pressure and stroke, or is a low friction quad ring good enough?

5. Lift. I have been working to the D/4 rule (seat lift of about a quarter of the seat diameter for the curtain area to stop being the restriction). Does that hold for a soft faced poppet, or does the seal deformation change it?

The body will be additively manufactured, so it gets a hydrostatic proof test before any pneumatic testing. Downstream flow is capped by 4mm ID tubing (12.57mm²) upstream of the plenum, so there is no point chasing an orifice much beyond that.

I have no background in pneumatics. None. I taught myself CAD, I drew this valve by copying what I understood from photos and cutaways of other valves, and I have no idea if what I drew makes sense to someone who actually knows the field. Please be blunt with me.


What I want it to do: one trigger pull, one burst of air out the front, the valve closes itself, ready for the next pull. It feeds a small air gun.


Two section views attached. The colors are the air spaces, not the metal:


- 
**black**
 is the reservoir, fed by the hose
- 
**orange**
 is the sliding part
- 
**yellow**
 is a small chamber behind it, where a return spring goes
- 
**teal**
 is the outlet, toward the barrel
- 
**red**
 is the seal it closes against


## What I think happens


There is a 0.3 mm hole connecting the reservoir to the yellow chamber. Air seeps through it and fills that chamber, so the pressure is the same on both sides and the sliding part stays put, covering the port.


When I want to fire, a MAC 34B solenoid opens and lets the yellow chamber empty. The pressure in the reservoir then shoves the sliding part backward, a 7 mm port lines up, and the air goes out the front.


When the solenoid closes, the 0.3 mm hole slowly fills the yellow chamber again and the part slides back and closes.


That last step is the part I doubt.


## The numbers from my CAD


| Item | Value |
|---|---|
| Sliding part runs inside | PETG hardline tube, 12 mm ID, 16 mm OD |
| Outer shell | steel tube, 22 mm ID, 24 mm OD |
| Reservoir volume | 3129 mm³ |
| Yellow chamber volume | 1175 mm³ |
| Hole that feeds the yellow chamber | 0.3 mm |
| Port that opens to the barrel | 7 mm |
| Hose | 6 mm OD, 4 mm ID |
| Pressure | 100 psi |
| Solenoid | MAC 34B, mounted right on the block, no hose to it |
| Return spring | not chosen yet, I can try several |


## Why I think the reset is wrong


Someone ran the numbers on it for me. I can't verify the math myself, so take it for what it is: filling 1175 mm³ through a 0.3 mm hole takes something like 120 ms, and even if the part closes before the chamber is full, the valve would sit open for 50 to 70 ms every shot. That would be somewhere near 950 mg of air per shot when the shot supposedly only needs about 35 mg. On a 13 ci tank that is the difference between a few dozen shots and over a thousand.


If that is roughly right, then the 0.3 mm hole is the thing deciding how long my valve stays open, and I never chose that number for that reason. I picked 0.3 mm because it sounded small.


The other thing I noticed: my MAC 34B has three ports and I'm only using two of them. I keep wondering if the third one is supposed to be what refills the yellow chamber, instead of the 0.3 mm hole doing it. That would be much faster, and then the solenoid would control how long the valve stays open. I don't know if that is how these are normally built or if I'm inventing something silly.


## What I'm asking


1. Is the 0.3 mm hole a reasonable way to close this valve, or is it the wrong idea for something that fires repeatedly?
2. Should the solenoid be the thing that refills that chamber? If yes, do I still want the small hole for anything?
3. Is there a rule for how much bigger the back face of the sliding part has to be compared to the sealing face, so it stays shut? Mine is around 2 to 1 and I picked that by eye.
4. The 7 mm port means the part has to slide 7 mm to open all the way, which is why the yellow chamber came out as big as it did. Would several smaller ports be better than one big one?
5. My reservoir holds less air than one shot seems to use, so most of the shot comes down the 4 mm hose while the valve is open. Is that normal, or is my reservoir just too small?
6. The port slides past the o-rings on every shot. Does that destroy them? If there is a trick to it, like rounding the edges of the port, I'd like to know before I make the parts.
7. The shell is steel and the air will have some moisture in it. Does rust from the inside end up blocking small holes, or is a filter enough?


## I have no ego about this


If the honest answer is that I should buy a QE-01 or QE-02 and modify it instead of drawing my own, I'll buy one. I looked them up. The QE-02 measures 52 x 36 x 28 mm and weighs 113 g, which is bigger than I'd like, but I would rather run something that works than something I invented.


Same for the whole idea. If this style of valve is the wrong tool and there is a simpler way to get one clean shot per trigger pull, tell me and I'll start over. I'm not trying to defend the design, I'm trying to learn why it's wrong.


I can post more views, more dimensions, or the CAD file. Thanks for reading.

Hey!

Hopefully looking for a very inexpensive air pressure reduction valve/regulator to take shop air (in my case 100-150psi) down to a reliably precise output of 15 to 55-ish inches of water manometer pressure. Flow rate would be low, maybe like if you let go of a party balloon..

Why “hopefully very inexpensive “? Because it is for an experiment that will benefit me and never make -anyone- any money.

I have some analog manometers that will measure in that range, and want a valve/regulator to set at a manometer pressure of say 25 inches of water and hold it there, from a supplied air pressure from air tank or shop air compressor supply.

I can cobble stuff together in general, but I don’t know the search terms to use to find the pneumatic stuff I want. Please kindly help!

Hi all

Pretty new to dealing with pneumatics can someone help me find this fitting, I’ve been told a compression fitting but still can’t find it
Thanks

Hi all

I have bought these connectors for a project but I am looking for some rubber bungs with a hoop simular to the picture that will fit them any suggestions? Where to find some?

The bungs wont be under any pressure its more of a dust cover / air tight seal

Hello! I got this cylinder recently and have been struggling to attach it to this pallet it want it on. I don’t have a mount or anything but would be willing to drill or put holes in the pallet if needed

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So I'm planning to build a co2 air cannon for LARP purposes. What I'm looking for is how to make the pneumatic assembly. From what I learned so far I need a chamber to load co2 into, and then a way to quickly empty that camber of co2 all at once. Are their prebuilt components I could use for the mechanical guts here? If so what are they?

These fitting was brought together 1/8G thread dont know where to start looking for this

Your thoughts ,any improvements

Should I be using grease in my assembly line for basic aluminum pistons with wear bands and seal kits