triple asco valve cannon PROBLEM

[I3IV]

Hi all,
I'm building my cannon with 2 asco valves(1.5 in.) and 1 goyen valve (1.5 in.). Pictures attached:

The 2 hoses coming from the "horns" to the body are just part of the chamber. 3 hoses coming from 1/8 pilot ports of the 3 valves to a tee. One hose comes from the tee to the 1/4 ball valve as the trigger. I have a loud leak coming from the 3/8 exhaust port of the left asco valve (picture) and maybe some other places but right now that spot is the most obvious . I think the valve is defective but before taking apart or do anything stupid I need the pro's opinions.

Thanks all.

[jrrdw]

Use something like bubble magic with a brush or spray bottle to coat the joints and connections and look for bubbles.

Stopping all the little combined leaks may indeed solve your valve issue. Some valve's will have the tendency to be harder to seal, more so when new. Stopping the leaks may give the extra pressure needed to seal the valve.

Welcome to Spudfiles.

[jackssmirkingrevenge]

Looking good, I'm reminded of the Hochdruckpumpe



Sometimes not filling fast enough causes leaks but this would be coming out of the barrel end, I'd wager it's more likely that your diaphragm is damaged or needs cleaning.

[I3IV]

So I checked for leaks...Only that spot is my problem. So I opened that one up and the one on the right. I discovered that the leaky one's missing a spring on top of the pilot diaphragm. They both have no spring on the main diaphragm though...I already ordered parts...hopefully that will fix the problem. I'm going to fill the chamber with a pcp pump...Do you guys think it will be good/fast enough to seal my valves.

[jackssmirkingrevenge]

I'm going to fill the chamber with a pcp pump...Do you guys think it will be good/fast enough to seal my valves.

Hard to say since those pumps put more of an emphasis on pressure than volume. You might need to prefill with a compressor first then take it to full pressure with the pump, or if portability is a concern, fill a paintball bottle or similar and dump it into the chambers to give it a boost. What pressures do you intend to run at?

[Braddubya]

Is there an advantage to 3 valves? The pressure in the barrel once the valve opens can only be as high as the pressure in the chamber requardless of the number of valves. I would think that unless you had a very large barrel that the third valve would yeild
a negligible performance increase. I am not familiar with these specific valves so I do not mean to criticize I am just genuinely curious.

[farcticox1]

BIG FLOW, flow is king, and pressure, pressure and flow. :king: :queen:

[jackssmirkingrevenge]

I would think that unless you had a very large barrel that the third valve would yeild
a negligible performance increase. I am not familiar with these specific valves so I do not mean to criticize I am just genuinely curious.

Honestly, it's a fair criticism. There probably won't be a visible performance increase with this configuration compared to a single valve and one chamber equivalent to the volume of the three chambers, unless the projectile is extremely light vis a vis its cross-section or the barrel has a much larger diameter. The use of multiple valves also creates more turbulence which reduces efficiency.

[I3IV]

Well...I have the same doubt. There would probably be very slight improvement if any with 3 valves. But I got them for quite a good price and I also don't have a need for 3 cannons so I decided to try this design. BTW, this is a project for an art class, I will put a skull in the middle as the front handle + trigger guard so the looks more important to me. Back to the problem...The 2 asco valves are missing springs on the main diaphragms and 1 spring on pilot diaphragm.The springs I ordered are wrong...Is there a way to find out exactly what part number those are? And is it possible to get to 100-150 psi with a pcp pump? The chamber volume is quite big...AND does my pilot volume look big at all? should I remove the hose and connect the ball valve directly to the tee instead? Sorry for asking too many questions

[I3IV]

Ok It is now air tight! takes about 80 pumps to get to 50 psi HOWEVER it does not shoot when triggered air goes out through the ball valve instead. Im thinking even if the left asco valve is falty( replacement springs are stiffer than original springs) as long as the system is air tight the other 2 should still shoot, correct? The asco model is flex kleen M28244 and goyen is RCA45T which everyone uses and I don't see a problem with the set up. Waiting for everyone's opinions.

[Braddubya]

Honestly, it's a fair criticism. There probably won't be a visible performance increase with this configuration compared to a single valve and one chamber equivalent to the volume of the three chambers, unless the projectile is extremely light vis a vis its cross-section or the barrel has a much larger diameter. The use of multiple valves also creates more turbulence which reduces efficiency.

Yeah those were my thoughts exactly but as the OP pointed out it does look cool and very steampunk

does my pilot volume look big at all? should I remove the hose and connect the ball valve directly to the tee instead? Sorry for asking too many questions

There isnt much volume in those hoses. Worst case scenario the extra volume would just create a short delay when you fired it as it has to vent off that volume and pressure for all three hoses. That said I would make sure that you have all of your hoses the exact same length or you will get them firing at different timings. That may already happen actually since one is a different valve. I dont think it would be noticeable though.

One thing that would be cool that I just thought of is you could use 3 different lengths of hose. say 8" 16" and 24" (these are all made up estimates). It would take some trial and error testing, but you could use different pilot volumes so that the valves would fire sequentially like in that big German gun posted earlier. There is no practical advantage to this in terms of efficiency but frankly I dont think it will make it noticeably worse and it may have a much more interesting sound and effect. Considering it is an art project that may be a very good thing.

[jackssmirkingrevenge]

The springs I ordered are wrong...is there a way to find out exactly what part number those are?

Do you have the exact valve model? There must be a diagram floating around the web somewhere.

And is it possible to get to 100-150 psi with a pcp pump? The chamber volume is quite big

It's possible... but if you intend to operate at these pressures, you're better off with a higher flow/lower pressure track pump like this:

does my pilot volume look big at all?

Since it's thin tubing, not so bad, but it looks like there's potential to shorten it considerably.

should I remove the hose and connect the ball valve directly to the tee instead?

Less volume is almost always better. Consider a small quick exhaust valve for a better and more consistent piloting.

[I3IV]

The springs I ordered are wrong...is there a way to find out exactly what part number those are?

Do you have the exact valve model? There must be a diagram floating around the web somewhere.

Yes I order another asco M28244 on amazon for $30. I took the 2 springs and valves from this new valve and put them in the faulty left valve on the build. When triggered, air goes straight out of the ball valve! All tests done at around 60-70 psi...that's a lot of pumping :bounce: The 2 good valves did not open either. I even opened up all of them to look at but nothing seemed wrong. My last chance is to probably take each of them apart to test separately which is a pain and I should have done from the beginning before putting them together but I can't see what unique difference that makes compared to original 3 valve setup. What you guys think?

[jrrdw]

I think you need a upgraded piloting system to do the task your asking of it. A stronger one. Higher pressure on the piloting side how ever you can make that happen. Increasing the flow rate through larger porting on the pilot would also help.

Keep at it, you're making something that the engineers of the valves never intended them to do X 3.

[I3IV]

This is my quick setup to test the left and right asco. They both work!

I think jrrdw is right. My pilot seems to be the problem...bad flow probably. So what do you guys think I should do to pilot? a 1" sprinkler valve? or this:

The problem with this new setup I see after digging around the forum is the QEVs can't be filled from A without some sort of modding. That means I cannot exhaust through P if my pilot air comes though A...? These are 1/8 QEVs, will the quck release I get from them compensate the bad flow?