PDA

View Full Version : Why the Use of LP Solenoids?



SlartyBartFast
04-29-2005, 10:43 AM
Most of the LP hype and misinformation IMO is to coverup the fact that instead of using LP operation because it's more efficient or superior, it's because the components used can't handle HP.

The biggest example of this is the solenoid valves used in all the electropneumatic markers. Even the "LP" pressures hyped as the next best thing by the marker manufacturers are surpassing the rated wirking pressures on a number of the solenoids used.

So, why isn't a HP solenoid developed for paintball?

Craig Palmer says the quick switch will handle 300 psi. So, why not use a mechanical solenoid to operate a quickswitch?

Or, for that matter, why not use a LP solenoid to operate another HP valve?

Just laziness on the aprt of marker designers?

Tom Kaye always said higher pressure could result in a more efficient marker. It would beinteresting to try and tune a Shocker, Matrix, ION, or other dump chamber/spool valve marker to use Mag chamber pressures or higher and see...

Chronobreak
04-29-2005, 11:44 AM
i thought mose the larger solenoids had also a larger operating power(more or alrger/stronger batts) and they were also a larger unit alltogether.

RRfireblade
04-29-2005, 12:15 PM
It's much easier to move lower pressure air, at faster speeds, using less power and creating less drag,friction and wear on the related parts and seals.

That's why. ;)

Oh, and all Hype aside, IMO... if it's possible to run lower internal pressures overall, it almost always a better thing.

RRfireblade
04-29-2005, 12:21 PM
And on a related note, that's why the Mq Valve is such an achievement.

SlartyBartFast
04-29-2005, 12:44 PM
It's much easier to move lower pressure air, at faster speeds, using less power and creating less drag,friction and wear on the related parts and seals.

That's why. ;)

Oh, and all Hype aside, IMO... if it's possible to run lower internal pressures overall, it almost always a better thing.

Well, that's only opinion.

And as far as moving more air at higher speeds, it's completely wrong.

We're waiting on the Mq valve. I suspect it incorporates what I'm contemplating now.

LP is used for only two reasons. Reduce the forces in operating componants such as rams so cockers don't decimate paint or require rediculously tiny cross-section pistons and because the electropneumatic marker designers had to design their markers around existing solenoids.

RRfireblade
04-29-2005, 12:48 PM
It not opinion.

Measure the force to switch a 3 way at 50 psi and at 300 and let me know what you find out.

It's cool tho, I figured like everything else around here that would create an arguement. ;)

Piloted circuits help on a few of those regards but not all. Which what I figure the Mq is based on since there already is a commercial valve on the market very similar to his just larger.

SlartyBartFast
04-29-2005, 01:06 PM
Measure the force to switch a 3 way at 50 psi and at 300 and let me know what you find out.

I'm not arguing actuation force. I'm talking about air flow.

RRfireblade
04-29-2005, 01:10 PM
Nothing that I stated and you then claimed was 'my opinion' mentioned anything of air flow.

The posted question was not about airflow either BTW.

CoolHand
04-30-2005, 03:33 AM
OK, I can't help myself here.

With any system, if you minimize the head losses, you will also minimize the pressure required to flow a given volume. By the very nature of the problem (all other things being equal), the system running at the lower pressure will be more efficient, because you aren't wasting energy on head losses.

If you take and run a Viking at 500 psi the efficiency would go to hell (among other things, but bear with me). It only requires so much energy (volume and pressure) to make the ball go. Now, currently it will do it at 200 psi. As so many here love to claim, every marker ends up with about 60 psi behind the ball. So, to get 60 psi at the ball, they start with 200 psi at the reg. Now, all the rest of that energy is lost to shock losses and other head losses (like friction). That said, head losses are proportional to volume and pressure (but moreso to pressure, as the volume is also dependant on pressure). If the pressure goes up, the losses go up. You still need 60 psi to move the ball, but now you are starting from 500 psi at the reg. Well, you can use 2.5 times less air, right? Wrong. All that extra pressure increases the shock losses and frictional head losses, so by the time the air gets to the bolt, much of the added energy you started with is now gone. Put simply, you wasted a bunch of energy (which means the efficiency of the system went down).

The reason the Mag needs to have 850 psi to the valve is because of the extraordinarily small passasges and transitions that are used inside the valve. A lot of the energy brought into the valve is wasted on shock losses. If uber high pressures and tiny cross sections were the ultimate recipe for efficiency, shouldn't Mag's be the one's shooting a case on a 68/4500 fill?

If the common knowledge is correct, and every marker does end up with ~60 psi be put on the ball, then common sense dictates that the system that starts at the lowest energy state (lowest pressure) is the most efficient.

Not to mention that the HP systems are more dangerous. Why oh why would a company knowingly design a system which must be supplied input pressures in excess of what the industry standard hardware can handle? You think that brass elbow is made to work at 1000psi? Riiiiiiight. Try 300 psi working pressure, 1000 psi burst. Same with macro fittings, macro line, QD's, and stainless hosing. None of the stuff used on Mags is rated for the pressures they work at, yet that is OK with everyone. But look out if a marker has ramping software, that is going to kill someone and end paintball. :rolleyes: ^3

LP markers are a whole lot safer to plumb, and a whole lot easier to seal (try designing an oring seal to hold 150 psi verses 1000 psi).

LP has its advantages, but don't say that too loudly around here . . . . .

magmonkey
04-30-2005, 05:36 AM
one thing to keep in mind.
volume and preasure.
what you have is a three way designed to run HVLP
A three way could be designed to be WAY smaller if it we designed to run at LOW volume High presure,
and in my thinking
small internal area+ smaller orings+ less friction= just as smooth of an opperating valve at higher presure.

almost EVERYTHING we use could be scaled down, because you don't need the volume if you have the presure.


and on another note
and look at the presure ratings on the elbows, and QDs in the agd store.
I think it is foolish to run micro or macro on ANY setup, I'll keep my knuckles un cut up thanks

Twiek
04-30-2005, 06:39 AM
With any system, if you minimize the head losses, you will also minimize the pressure required to flow a given volume. By the very nature of the problem (all other things being equal), the system running at the lower pressure will be more efficient, because you aren't wasting energy on head losses.

If you take and run a Viking at 500 psi the efficiency would go to hell (among other things, but bear with me). It only requires so much energy (volume and pressure) to make the ball go. Now, currently it will do it at 200 psi. As so many here love to claim, every marker ends up with about 60 psi behind the ball. So, to get 60 psi at the ball, they start with 200 psi at the reg. Now, all the rest of that energy is lost to shock losses and other head losses (like friction). That said, head losses are proportional to volume and pressure (but moreso to pressure, as the volume is also dependant on pressure). If the pressure goes up, the losses go up. You still need 60 psi to move the ball, but now you are starting from 500 psi at the reg. Well, you can use 2.5 times less air, right? Wrong. All that extra pressure increases the shock losses and frictional head losses, so by the time the air gets to the bolt, much of the added energy you started with is now gone. Put simply, you wasted a bunch of energy (which means the efficiency of the system went down).

That's only part of the story. You can run a poppet valve at high pressures and get great effeciency... It has less to do with losses and more to do with operation principle. In fact, the two most effecient marker designs are HP (Nelson based pumps, and Palmer's valve train, which is an improved sheridan valve). As a whole, though, poppet valves are effecient (at any pressure). And as a whole, dump chambers are relatively ineffecient, especially at lower pressures. This is what Tom was (probably) refferring to when he talked about increasing pressure... dump chambers are naturally more effecient at higher pressures. Now, that's not to say that marker x at a higher pressure is always more effecient that marker y at a lower pressure, but the theory is sound.


The reason the Mag needs to have 850 psi to the valve is because of the extraordinarily small passasges and transitions that are used inside the valve. A lot of the energy brought into the valve is wasted on shock losses. If uber high pressures and tiny cross sections were the ultimate recipe for efficiency, shouldn't Mag's be the one's shooting a case on a 68/4500 fill?

Thre reason the 'mag runs on "850" psi is because of the dump chamber size (~0.55 ci) and the use of a reg. The dump chamber takes 400-450 psi (for non-LX) to get a ball up to 290 fps, period. It has nothing to do with the size of air passages... those don't determine the operating pressure of a dump chamber marker. Most regs take a certain amount of pressure drop to keep flow going, therefore the need for more than 450 psi into the reg. You don't have to use 850 psi (on non-LX), though... I've run them at ~550 and not had a problem.

Twiek
04-30-2005, 06:51 AM
So, why isn't a HP solenoid developed for paintball?

IIRC, the solenoid in the Ion was specificly designed for paintball... and it can operate up to at least 200 psi. If you used different materials, it might be able to handle more, but I suspect the limitation for that valve is the EM strength of the coil.


Craig Palmer says the quick switch will handle 300 psi. So, why not use a mechanical solenoid to operate a quickswitch?

As RR said, it takes more energy to switch. I'm planning on using a 'cocker 4-way as a solenoid valve in one of my designs for a plethora of reasons. The (slightly) increased battery use isn't that big of a deal to me... it'll still get significantly more shots per battery/charge than a sear tripper.


Or, for that matter, why not use a LP solenoid to operate another HP valve?

There are piloted designs out there, and IIRC, some of the earlier electro 'markers used them... but they're bigger and slower than direct operated valves.

tyrion2323
04-30-2005, 08:22 AM
RRFireBlade and Coolhand,

Didn't you get the memo? If the 'mag doesn't have it, it's hype.

Just thought you ought to know :rolleyes:

CoolHand
05-01-2005, 12:14 AM
Twiek, man, you're right, I'm totally missing the principals here.

Your common knowledge picked up from paintball forums has far outstripped all of what I have learned in my engineering classes. Compressible flow and fluid dynamics < AO

I swear, there is no roll eyes smiley big enough for this one. :rofl:

I quit. There is no amount of explaining that I can do to change anyone's minds here, so I am done trying.

If anyone needs me, I will be setting over in the corner with my fingers in my ears, repeating over and over again "Its just an internet forum, walk away.", "Its just and internet forum, walk away." . . . . . .

Enemy
05-01-2005, 12:27 AM
anyone forgetting the higher the operating pressure the higher pressure the gun will fail to work at! so what happens when the tank hits 1000 on the mag it starts starving for air. so what happens to that last 600 psi(if your lucky) left in that tank is lost/ wasted energy!! this combined to what coolhand and rrfireblade have stated makes the true advantages to lower pressure a big deal!!

Twiek
05-01-2005, 10:01 AM
Twiek, man, you're right, I'm totally missing the principals here.

Your common knowledge picked up from paintball forums has far outstripped all of what I have learned in my engineering classes. Compressible flow and fluid dynamics < AO

I swear, there is no roll eyes smiley big enough for this one. :rofl:

I quit. There is no amount of explaining that I can do to change anyone's minds here, so I am done trying.

If anyone needs me, I will be setting over in the corner with my fingers in my ears, repeating over and over again "Its just an internet forum, walk away.", "Its just and internet forum, walk away." . . . . . .

Wow, there seems to be a lot of this on this forum, "I'm right because I learned it in a classroom," and "your wrong because you don't know what you're talking about."

But since you know all about me, my education, my experience and knowledge of paintball, and even what groups of people I participate in discussions with, I guess I don't need to tell you.

Furthermore, I didn't totally disagree with you. If you lessen the losses of a particular system, it will be more effecient. This is what AKA has done with the Viking, Excalibur, and Merlin.

However, as I said in my previous post, a marker can still be highly effecient at high pressures, and I gave examples as such. Scientific discovery always outstrips theory. If you know that Item A is true and Item B is true from scientific experimentation, but Theory X says that Item B is false, then Theory X is wrong. You yourself even stated that the "LP theory" hinges on the "common knowledge" fact that all markers end up with 60 psi behind the ball. I can tell that you're incorrectly applying some of the theory, and some of your stated "facts" are simply (and experimentally proven) wrong.

CoolHand
05-01-2005, 10:29 AM
. . . However, as I said in my previous post, a marker can still be highly effecient at high pressures, and I gave examples as such. Scientific discovery always outstrips theory. If you know that Item A is true and Item B is true from scientific experimentation, but Theory X says that Item B is false, then Theory X is wrong. You yourself even stated that the "LP theory" hinges on the "common knowledge" fact that all markers end up with 60 psi behind the ball. I can tell that you're incorrectly applying some of the theory, and some of your stated "facts" are simply (and experimentally proven) wrong.

No where in that did I say that a high pressure marker cannot be efficient, look at any 12g pumper. I said, give all things being equal in a system, the lower pressure it will run at, the higher the efficiency (without changing dwell, or chamber sizes, but still getting the energy needed to shoot the ball 290 fps).

You need to read more, and have a little smaller chip on your shoulder. Book learnin' ain't bad, but it is far more useful than those without it would like to believe. I cite no "facts" real or imagined above. I simply layed out an argument based on what every single person uses as their trump card when the age old "LP myth" argument arises. Call it debunking.

Also, the assertion that poppet valves are "efficient" at many pressures is false. For any one valve, there will be a pressure at which it performs its best. One pressure. Above or below that mark, it will still work effectively, but it will not perform at 100%. What you call "efficient" is really just accpetable efficiency, and all that means is that the valve is still working in the envelope around its optimum pressure. That is why the Viking is so effiecent, but a 'cocker is not quite so good. The Vik is running where they designed it to, while the 'cocker is generally not.

Like I said before, if you can't wrap your mind around it, I can really help you. Everyone here likes to spout about "scientific" this or that, until they really have to apply it.

Twiek
05-01-2005, 01:43 PM
I said, give all things being equal in a system, the lower pressure it will run at, the higher the efficiency (without changing dwell, or chamber sizes, but still getting the energy needed to shoot the ball 290 fps).

You can't keep all things equal in a system and expect it to operate at a lower pressure than previously. You're changing something in order for it to still reach a certain velocity at a different pressure. In AKA's design philosophy, that means increased port sizes, better gas routing, etc. which is a sound way of decreasing operating pressure and increasing effeciency. But not all changes that lower the pressure increase effeciency, and not all changes that increase effeciency lower pressure.


Also, the assertion that poppet valves are "efficient" at many pressures is false. For any one valve, there will be a pressure at which it performs its best. One pressure. Above or below that mark, it will still work effectively, but it will not perform at 100%. What you call "efficient" is really just accpetable efficiency, and all that means is that the valve is still working in the envelope around its optimum pressure. That is why the Viking is so effiecent, but a 'cocker is not quite so good. The Vik is running where they designed it to, while the 'cocker is generally not.

I never said any one valve will work perfectly at a variety of pressures, I said "poppet valves are effecient (at any pressure)" i.e. poppet valves in general. Yes, I know all about "sweet spotting" a valve.

A 'cocker can be as effecient as a Viking (if not more effecient). What most people do, though, is install a super light valve spring to lower the operating pressure and then slap loads of aftermarket parts in, thinking that "LP is more effecient". A 'cocker is an HP marker, no mistake, designed when CO2 was the only available gas source and nobody knew what LP meant. 'Cockers are therefore (typically) more effecient at higher pressures.


You need to read more, and have a little smaller chip on your shoulder. Book learnin' ain't bad, but it is far more useful than those without it would like to believe.

Again, you're making assumptions about someone you don't at all know.


Like I said before, if you can't wrap your mind around it, I can really help you. Everyone here likes to spout about "scientific" this or that, until they really have to apply it.

Wow, talk about a chip on your sholder. I don't know who's more condecending, you or RR.

Unless you haven't already figured it out through the subtle hints I've been giving you thus far, I'm not some blithering idiot that dropped out of high school and reads PBN to get all his facts. But I don't feel I have to tell you my education level, the classes I've taken, the positions I've held, what qualifications I have, what markers I own, etc. to get a point across. I'd like to think that arguments stand on their own merit, and not on the education level of the person giving them.

Maggot6
05-01-2005, 02:18 PM
He he, twiek and coolhands argument is entertaining me...But anyways, a question for coolhand...


The reason the Mag needs to have 850 psi to the valve is because of the extraordinarily small passasges and transitions that are used inside the valve. A lot of the energy brought into the valve is wasted on shock losses

So, does that mean if you magically made a mag's passeges like 5x the size, it would run at a lower pressure?

Chronobreak
05-01-2005, 04:39 PM
He he, twiek and coolhands argument is entertaining me...But anyways, a question for coolhand...



So, does that mean if you magically made a mag's passeges like 5x the size, it would run at a lower pressure?

yes but it would be 5x+ as big

too ways of doing things= HP and small holes/ports/routing or (small volume)

LP=and large holes and ports etc (large voulme)

make sence?

CoolHand
05-01-2005, 05:19 PM
. . . . . Again, you're making assumptions about someone you don't at all know. . . . .


And once again, it is you who is assuming, and once again, it is you who is not seeing what I am talking about.

If you haven't gotten it by now, you're not going to.

I don't know you, and really, I don't care. I am talking about something in general, in a theoretical sense, and you come in, apply what I said to two markers that aren't equal, and that I just referred to in passing, and then simply smile and say I'm wrong.

You're not listening, and I don't care enough to waste any more time on you.

Go on thinking whatever you want to, say you won the argument, say I don't know jack, say whatever you want to. I just don't care.

When will I learn to just stop posting here . . . . . . . .

Twiek
05-01-2005, 05:36 PM
And once again, it is you who is assuming, and once again, it is you who is not seeing what I am talking about.

If you haven't gotten it by now, you're not going to.

I don't know you, and really, I don't care. I am talking about something in general, in a theoretical sense, and you come in, apply what I said to two markers that aren't equal, and that I just referred to in passing, and then simply smile and say I'm wrong.

You're not listening, and I don't care enough to waste any more time on you.

Go on thinking whatever you want to, say you won the argument, say I don't know jack, say whatever you want to. I just don't care.

When will I learn to just stop posting here . . . . . . . .

The cop-out defence.... pretty much impenetrable :rolleyes:

What exactly is it that I'm "missing"? You make a point, I make a counter-point. This is how discussions proceed. Or do I not "get it" simply because I disagree with you :rolleyes: