Super Soaker Central forums

scupper · 10-03-2007, 08:56 AM

I believe you are correct in that temperature would not be a factor, but I believe the rubber rod would have to be fairly rigid so the valve opens and closes quickly. Thanks for asking.

Drenchenator · 10-03-2007, 09:11 AM

I would recommend "Medium Soft" for the hardness based on the chart. The rest of the factors do not seem to matter in this application. I wouldn't want the rubber to be too hard because it would be too hard to get into the valve body. We are not stretching the rubber at all so stretch and tensile strength do not matter.

I do have to recommend something else. I didn't realize that the valve would create an extreme amount turbulence if the hole is way too small.

This image I found should demonstrate the problem. The optimal situtation is of course having the hole be as large as the pipe on both the input and output sides of the valve. iSoaker brought this up early on in this topic. I was planning on making it larger in my final version. Basically, try to make the hole as large as possible to avoid turbulence. Ideally, the hole should be the same size.

Another option is available. Make two sections of rubber, a bottom one and a top one. The top serves as a "plug"; the bottom as the valve. Normally, a spring pushes the bottom up into the top, sealing that valve shut. A downwards pull on the bottom one would open the valve then.

You could also make a conical section lead up and another to lead away from the valve hole. This would create laminar flow as shown in the image. The idea is to avoid "sudden" changes in cross-sectional area.

WaterWolf · 10-03-2007, 09:57 AM

Its almost as if you read my mind

.
For the reasons Isoaker had stated in that post, I too had been planning to experiment with a system of two pieces almost exactly like you described.
I'll post my results here once I've recieved the parts and built my trigger.

I had recently gotten stuck while building my newest homemade and I think that this valve may be the answer to my problems.

BTW, what should we make the official name for this valve?
Perhaps Linear-Homemade-Valve (LHV for short).

Drenchenator · 10-03-2007, 12:38 PM

Well, I guess "great minds think alike." I thought of that idea after remembering all of Ben's conical nozzles and how much better they perform than regular nozzles.

I have no problem with calling the valve "Linear-Homemade-Valve" or "LHV" for short. I had a lot of trouble coming up with a name for this valve because it is like a gate valve but it is also like a ball valve. Linear homemade valve accurately describes what the valve is, so I like it.

Specter · 10-03-2007, 03:21 PM

linear homemade valve seems a bit odd in pronunciation... it might be better to call it homemade linear valve... just a suggestion

WaterWolf · 10-03-2007, 03:25 PM

Quote:

Linear homemade valve accurately describes what the valve is, so I like it.

Glad to help, and thanks for your advice.

Order to McMaster confirmed, will be shipped today.
It shall be interesting to build a scaled up model of your 1/2 inch valve.

If this one works well, I might try something crazy, like a massive 2" LHV.
Imagine the flow on that beast.

Drenchenator · 10-03-2007, 05:30 PM

Quote:

linear homemade valve seems a bit odd in pronunciation... it might be better to call it homemade linear valve... just a suggestion

I have to agree; I didn't notice that earlier. For example, WaterWolf's check valve was a called a homemade check valve, so it would only make sense to call it a homemade linear valve. I don't care either way though. To tell the truth, I really like the acronym LHV over HLV. As long as it's called one of the two, it's okay with me because they describe the valve well.

@WaterWolf: Are you going to add the conical sections too? I can't wait to see your results on this. A scaled up version should perform extremely well.

WaterWolf · 10-03-2007, 05:53 PM

Yes, I'm going to see what I can whip up for a conicle inner shape. As well as testing its preformance in a WBL.

Drenchenator · 10-04-2007, 06:45 AM

Are you going to build a trigger system for it as well? I didn't really have much time to tackle a trigger system before leaving for college.

WaterWolf · 10-04-2007, 07:23 AM

Hmm,
For the homemade I'm hoping to use it in, the LVH is positioned such that a real trigger set-up would be unnecessary.
I might mess around with that though, just for the sake of experimentation.

isoaker_com · 10-04-2007, 08:30 AM

Are PVC cross-pipes with different diameters for the perpendicular parts easily found? I would imagine that if one used the thick pipe for where the linear valve gate goes while the thinner pipe would be for fluid flow, one would be able to drill a hole in the piston to be sure that would be the same diameter as the fluid-filled part. There would, of course, still be turbulence introduced if the valve is only partially opened, but that's true for most valves.

The thought of shaping the path through the valve opening makes sense only if the exit tubing is smaller than the incoming tubing. Hmmm... come to think of it, even if a PVC cross-pipe of different internal diameters (ID) is not available, one could make one's cross-pipe have different IDs by filling part of the tubing, then drilling it out similar to how Drenchenator ended up filling and drilling the gate part of the linear valve.

Drenchenator · 10-04-2007, 01:16 PM

Quote:

Are PVC cross-pipes with different diameters for the perpendicular parts easily found?

No, they aren't. However, you can by a size up and use bushings to use a smaller size pipe for the input/output. With a little work, the pipes can be flush against each other and the sizes can be different.

You can use female-threaded bushings to make the valve removable too. In all, I don't know why I just didn't use bushings in the first place; they would solve the whole diameter/turbulence issue. I guess the idea completely slipped my mind.

WaterWolf · 10-05-2007, 07:23 PM

My shipment arrived today.
Got one of my three projects nearly compleat, but found that the 1" rubber rod is not air-tight with the 1" PVC.
Any suggestions other than wrapping it in electric-tape or such?

Ben · 10-06-2007, 09:02 AM

I ran into a similar problem with seals in a Nerf gun of mine. 1 inch PVC has an average ID of 1.029 inches. The extra 0.029 inches does make a difference. This means that 1 inch outside diameter things won't seal in it.

Perhaps sticking a larger ID foam into the slot would work? Electrical tape also might work, but it's not an ideal solution.

WaterWolf, if you want a choice that would be good for a water balloon launcher, try the "Quick acting gate valves" I mentioned earlier. They're too large for most water guns, but for a water balloon launcher they would work good because they should open fast and have high flow. It's McMaster-Carr part number 46065K81 and it costs only $12.05. You can set this up with a few pipe bends so that all you need to do is pull back, exactly like a trigger.

Drenchenator · 10-06-2007, 10:04 AM

I can only recommend that you wrap it in electrical tape. I do know that 1/2" PVC will work with 5/8" rubber rod. 1/2" PVC has an ID .622" while the rod is .625".

I never really thought that the 1" rod wouldn't fit. With 1" PVC and up, the ID is basically the size, but I guess not completely. I guess we still have some bugs to work out of this system.

If you want to get an slightly larger size that will fit, I would recommend 1.5" schedule 80 PVC. McMaster says that the ID is exactly 1.500", perfect for 1.5" rubber rod.

10-03-2007, 08:56 AM	#31
scupper Scupper Join Date: Aug 2007 Location: Bridgewater, NJ Posts: 3 UserID: 1361	Linear FLow Valve I believe you are correct in that temperature would not be a factor, but I believe the rubber rod would have to be fairly rigid so the valve opens and closes quickly. Thanks for asking.

10-03-2007, 09:11 AM	#32
Drenchenator Administrator Join Date: Jun 2004 Location: Maryland Posts: 718 UserID: 320	I would recommend "Medium Soft" for the hardness based on the chart. The rest of the factors do not seem to matter in this application. I wouldn't want the rubber to be too hard because it would be too hard to get into the valve body. We are not stretching the rubber at all so stretch and tensile strength do not matter. I do have to recommend something else. I didn't realize that the valve would create an extreme amount turbulence if the hole is way too small. This image I found should demonstrate the problem. The optimal situtation is of course having the hole be as large as the pipe on both the input and output sides of the valve. iSoaker brought this up early on in this topic. I was planning on making it larger in my final version. Basically, try to make the hole as large as possible to avoid turbulence. Ideally, the hole should be the same size. Another option is available. Make two sections of rubber, a bottom one and a top one. The top serves as a "plug"; the bottom as the valve. Normally, a spring pushes the bottom up into the top, sealing that valve shut. A downwards pull on the bottom one would open the valve then. You could also make a conical section lead up and another to lead away from the valve hole. This would create laminar flow as shown in the image. The idea is to avoid "sudden" changes in cross-sectional area. __________________ The Drenchenator, also known as Lt. Col. Drench.

10-03-2007, 09:57 AM	#33
WaterWolf Senior Member Join Date: Feb 2007 Location: Central Vermont Posts: 132 UserID: 976	Its almost as if you read my mind . For the reasons Isoaker had stated in that post, I too had been planning to experiment with a system of two pieces almost exactly like you described. I'll post my results here once I've recieved the parts and built my trigger. I had recently gotten stuck while building my newest homemade and I think that this valve may be the answer to my problems. BTW, what should we make the official name for this valve? Perhaps Linear-Homemade-Valve (LHV for short). __________________ Captain-Canis: Founder of the Maple-Mountain-Marines. Terrifying, but oddly refreshing. -B.D.

10-03-2007, 12:38 PM	#34
Drenchenator Administrator Join Date: Jun 2004 Location: Maryland Posts: 718 UserID: 320	Well, I guess "great minds think alike." I thought of that idea after remembering all of Ben's conical nozzles and how much better they perform than regular nozzles. I have no problem with calling the valve "Linear-Homemade-Valve" or "LHV" for short. I had a lot of trouble coming up with a name for this valve because it is like a gate valve but it is also like a ball valve. Linear homemade valve accurately describes what the valve is, so I like it. __________________ The Drenchenator, also known as Lt. Col. Drench.

10-03-2007, 03:21 PM	#35
Specter Senior Member Join Date: May 2007 Location: bound brook, NJ -The flood town Posts: 360 UserID: 1090	linear homemade valve seems a bit odd in pronunciation... it might be better to call it homemade linear valve... just a suggestion __________________ My "arsenal": Storm 600 pistol (never finished fixing this), launcher- Model:Afterburner(AB) 1.0(Decommissioned), AB1.5, soon AB 1.1(2"rebuild) maybe ill get something else in the future My site

10-03-2007, 05:53 PM	#38
WaterWolf Senior Member Join Date: Feb 2007 Location: Central Vermont Posts: 132 UserID: 976	Yes, I'm going to see what I can whip up for a conicle inner shape. As well as testing its preformance in a WBL. __________________ Captain-Canis: Founder of the Maple-Mountain-Marines. Terrifying, but oddly refreshing. -B.D.

10-04-2007, 06:45 AM	#39
Drenchenator Administrator Join Date: Jun 2004 Location: Maryland Posts: 718 UserID: 320	Are you going to build a trigger system for it as well? I didn't really have much time to tackle a trigger system before leaving for college. __________________ The Drenchenator, also known as Lt. Col. Drench.

10-04-2007, 07:23 AM	#40
WaterWolf Senior Member Join Date: Feb 2007 Location: Central Vermont Posts: 132 UserID: 976	Hmm, For the homemade I'm hoping to use it in, the LVH is positioned such that a real trigger set-up would be unnecessary. I might mess around with that though, just for the sake of experimentation. __________________ Captain-Canis: Founder of the Maple-Mountain-Marines. Terrifying, but oddly refreshing. -B.D.

10-04-2007, 08:30 AM	#41
isoaker_com Super Moderator Join Date: Oct 2004 Location: Somewhere Posts: 271 UserID: 301	Are PVC cross-pipes with different diameters for the perpendicular parts easily found? I would imagine that if one used the thick pipe for where the linear valve gate goes while the thinner pipe would be for fluid flow, one would be able to drill a hole in the piston to be sure that would be the same diameter as the fluid-filled part. There would, of course, still be turbulence introduced if the valve is only partially opened, but that's true for most valves. The thought of shaping the path through the valve opening makes sense only if the exit tubing is smaller than the incoming tubing. Hmmm... come to think of it, even if a PVC cross-pipe of different internal diameters (ID) is not available, one could make one's cross-pipe have different IDs by filling part of the tubing, then drilling it out similar to how Drenchenator ended up filling and drilling the gate part of the linear valve. __________________ :: Leave NO one dry! :: iSoaker.com / iSoaker.net ::

10-05-2007, 07:23 PM	#43
WaterWolf Senior Member Join Date: Feb 2007 Location: Central Vermont Posts: 132 UserID: 976	My shipment arrived today. Got one of my three projects nearly compleat, but found that the 1" rubber rod is not air-tight with the 1" PVC. Any suggestions other than wrapping it in electric-tape or such? __________________ Captain-Canis: Founder of the Maple-Mountain-Marines. Terrifying, but oddly refreshing. -B.D.

10-06-2007, 09:02 AM	#44
Ben Founder Join Date: Mar 2003 Location: College Park, Maryland Posts: 6,016 UserID: 1	I ran into a similar problem with seals in a Nerf gun of mine. 1 inch PVC has an average ID of 1.029 inches. The extra 0.029 inches does make a difference. This means that 1 inch outside diameter things won't seal in it. Perhaps sticking a larger ID foam into the slot would work? Electrical tape also might work, but it's not an ideal solution. WaterWolf, if you want a choice that would be good for a water balloon launcher, try the "Quick acting gate valves" I mentioned earlier. They're too large for most water guns, but for a water balloon launcher they would work good because they should open fast and have high flow. It's McMaster-Carr part number 46065K81 and it costs only $12.05. You can set this up with a few pipe bends so that all you need to do is pull back, exactly like a trigger. __________________ Note: I am busy so if I am slow to respond, be patient. email: ben at sscentral dot org / Forum rules / Read this page before emailing me. Do not send me a PM or email with a water gun question if someone else could answer the question. Post at the forums. You will get a response from me along with others' views or ideas. Do not send me a PM or email about reading a certain post unless it's been a few days since you've posted. I try to read every post but do miss some.

10-06-2007, 10:04 AM	#45
Drenchenator Administrator Join Date: Jun 2004 Location: Maryland Posts: 718 UserID: 320	I can only recommend that you wrap it in electrical tape. I do know that 1/2" PVC will work with 5/8" rubber rod. 1/2" PVC has an ID .622" while the rod is .625". I never really thought that the 1" rod wouldn't fit. With 1" PVC and up, the ID is basically the size, but I guess not completely. I guess we still have some bugs to work out of this system. If you want to get an slightly larger size that will fit, I would recommend 1.5" schedule 80 PVC. McMaster says that the ID is exactly 1.500", perfect for 1.5" rubber rod. __________________ The Drenchenator, also known as Lt. Col. Drench.

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