_shorty_
New member
I think the idea is that you close/stop flow while there's still a level in your surge tank - making sure that the lines stay full of water.
Fast linear actuator for a linear surge valve
- Thread starter karimwassef
- Start date
I think the idea is that you close/stop flow while there's still a level in your surge tank - making sure that the lines stay full of water.
karimwassef
Active member
I thought you meant a weber reference in THIS post. Didn't see it here.
I'm looking for as simple a solution as possible and the fewer moving parts, the better. Multiple rotating discs require greater skill than I profess.
Each valve needs to be independently controlled. No cross coupled valves.
I'll give the weber closure some thought. I prefer a side opening (or upside down) anyway since a horizontal one may be susceptible to a vortex.
I'm looking for as simple a solution as possible and the fewer moving parts, the better. Multiple rotating discs require greater skill than I profess.
Each valve needs to be independently controlled. No cross coupled valves.
I'll give the weber closure some thought. I prefer a side opening (or upside down) anyway since a horizontal one may be susceptible to a vortex.
kcress
New member
Not multiple rotating disks. Only one rotates - like the vent on a Weber Kettle barbecue. How do you get less than one moving part?
Side opening? Horizontal? The rotary valve idea doesn't care which you use.
Here is a weber vent:
Use holes or slots or petal shapes - whatever.
I've worked with a 15lb actuator before and they are not a very smooth acting device. They tend to jump from one position to the other and with 30lb of force without some serious suport you risk it ripping itself apart. Maybe a lower force one would work but I would do some experimenting and make sure it's going to work the way you want and quietly. The actuated butterfly valve would probably a better way to use the actuator. Here's some ideas.
Get a gear head low rpm dc motor, I've seen 2,5&10 rpm models. They are real small but with 1000:1 gearing really strong. Build a wheel(doesn't need to be round from acrylic with a center hole for the motor and an offset pin, use a pushrod to connect the pin to the toilet flapper. It would work like an old fashioned steam engine but in reverse, as the pin moves from the 6 position to the 12 it opens the flapper, 12 to 6 it closes, the rpm of the motor decides cycles per min so that's one less thing to worry about, mounting above the tank would be somewhat simple. The connections would be a bit odd but not to difficult just use holes and pins to allow some movement in them.
The actuated valves you were thinking about earlier are probably the easiest way to do the surge though, I would expect you just need to open them up, figure out the stops in the wiring that make it only rotate 1/4 turn and remove. Then just connect to a power supply to be constantly running. There a bit pricy but a diy project with intermittent controller is probably only going to save $1-200 and take a few day minimum to build.
I like the idea of the magnets to slow the slam but if there too strong they will keep it open. Get some good boat fiberglass 2 part epoxy to encase them in and they'll be sealed.
Get a gear head low rpm dc motor, I've seen 2,5&10 rpm models. They are real small but with 1000:1 gearing really strong. Build a wheel(doesn't need to be round from acrylic with a center hole for the motor and an offset pin, use a pushrod to connect the pin to the toilet flapper. It would work like an old fashioned steam engine but in reverse, as the pin moves from the 6 position to the 12 it opens the flapper, 12 to 6 it closes, the rpm of the motor decides cycles per min so that's one less thing to worry about, mounting above the tank would be somewhat simple. The connections would be a bit odd but not to difficult just use holes and pins to allow some movement in them.
The actuated valves you were thinking about earlier are probably the easiest way to do the surge though, I would expect you just need to open them up, figure out the stops in the wiring that make it only rotate 1/4 turn and remove. Then just connect to a power supply to be constantly running. There a bit pricy but a diy project with intermittent controller is probably only going to save $1-200 and take a few day minimum to build.
I like the idea of the magnets to slow the slam but if there too strong they will keep it open. Get some good boat fiberglass 2 part epoxy to encase them in and they'll be sealed.
Maybe combine the webber vent idea with the low rpm motor? I would make the hole a wedge to maximize the open area. But it's pretty much two pieces of plastic with a hole drilled in each, put them both in a 2" coupling to keep the top from wandering, glue the bottom one down, and attach the other to the motor suspended over the tank with a shaft. Nothing would need to be precise other than the vertical distance
CyclistMT
More Idiot Than Savant
karim, respectfully, I believe your over thinking this in all aspects of your design including the size of your surge tank. I am all for out of box thinking but you reach a point that over complicating what you're trying to accomplish will only cause you anguish down the road. I think kcress was trying to allude to that in the post in his thread.
From kcress- My consul would be this. If you aren't into meticulous mechanical design and development then you shouldn't proceed with your outlined plan here. Instead you should work with standard products as they're a good bang for the buck and can be replaced when they wear out.
So let's try to take a K.I.S.S approach to this and see what we come up with. Ultimately it is your tank so you can do what you want but trust me, you want to enjoy the tank itself without constantly tinkering with the mechanical aspects of it (unless that's what you like about keeping a reef tank, of course). But maybe this is an alternate plan you could think about.
First, let's address the size of your surge. I have found a surge that's sized at 10% of the display volume is not only adequate but likely the most preferred from a usefulness standpoint without completely overwhelming the overflow. Your tank is planned at 380 gals. That gives us a 38 gal surge. Now, you said you wanted to do some randomization with it and a "double surge" at times. Ok, let's go with that and do 76 gals of total surge. Sticking with the Rubbermaid stock tank you can go with the 100 gal model and let it fill no more than 90 gals so you still have water left in the tank if you surge a full 79 gals (keeping the surge bubble less). This reduces that weight bearing load you have too. TRUST ME, surging 79 gals in that tank is going to be awesome. Your overflow may have problems keeping up.
Second, let's talk about how you're going to actuate your surge. Forget about the toilet bowl style seal. kcress is 100% right on that. It's going to thud when it closes and it's going to drive you crazy. I did a modified Borneman surge tank on my 150 gal and used a toilet flapper valve which was similar to what you have pictured and it always made a thump when it closed. And I could never totally eliminate air bubbles. I think you will risk inducing a vortex that will suck in air with that valve. I would recommend using a tried and true 2" electrically actuated ball valve. I don't think you need to go bigger than 2". I've actually reduced my 2" to 1.5" right at the outflow to increase velocity. It had minimal impact on the actual drain time of the surge but it really helped push the water across the tank. I have an Asahi valve with a 5 second run time. That's plenty fast and I have no water hammer. Hayward makes a valve with a 2 second run time if you think you need something faster. There is a hum when the valve actuates but no "flushing" sound or thud of a flapper closing. And NO bubbles.
Third, the control. Admittedly I'm out of my element here but I'm sure others smarter than me can help you out with that. That being said I think you could still do some sort of randomization or at least timer control with 555 timers, relays, etc. Or maybe even Arduino. Again, I don't know much about that so I can't guide you here but I would guess you could use one of those solutions with the actuated ball valves (my valve uses a relay with a timer built in). One thing you will need to pay attention to though is duty cycle so you don't burn out your valves.
I hope that helps and gives you an alternative to consider.
Current music selection: Adelitas Way - Hurt
From kcress- My consul would be this. If you aren't into meticulous mechanical design and development then you shouldn't proceed with your outlined plan here. Instead you should work with standard products as they're a good bang for the buck and can be replaced when they wear out.
So let's try to take a K.I.S.S approach to this and see what we come up with. Ultimately it is your tank so you can do what you want but trust me, you want to enjoy the tank itself without constantly tinkering with the mechanical aspects of it (unless that's what you like about keeping a reef tank, of course). But maybe this is an alternate plan you could think about.
First, let's address the size of your surge. I have found a surge that's sized at 10% of the display volume is not only adequate but likely the most preferred from a usefulness standpoint without completely overwhelming the overflow. Your tank is planned at 380 gals. That gives us a 38 gal surge. Now, you said you wanted to do some randomization with it and a "double surge" at times. Ok, let's go with that and do 76 gals of total surge. Sticking with the Rubbermaid stock tank you can go with the 100 gal model and let it fill no more than 90 gals so you still have water left in the tank if you surge a full 79 gals (keeping the surge bubble less). This reduces that weight bearing load you have too. TRUST ME, surging 79 gals in that tank is going to be awesome. Your overflow may have problems keeping up.
Second, let's talk about how you're going to actuate your surge. Forget about the toilet bowl style seal. kcress is 100% right on that. It's going to thud when it closes and it's going to drive you crazy. I did a modified Borneman surge tank on my 150 gal and used a toilet flapper valve which was similar to what you have pictured and it always made a thump when it closed. And I could never totally eliminate air bubbles. I think you will risk inducing a vortex that will suck in air with that valve. I would recommend using a tried and true 2" electrically actuated ball valve. I don't think you need to go bigger than 2". I've actually reduced my 2" to 1.5" right at the outflow to increase velocity. It had minimal impact on the actual drain time of the surge but it really helped push the water across the tank. I have an Asahi valve with a 5 second run time. That's plenty fast and I have no water hammer. Hayward makes a valve with a 2 second run time if you think you need something faster. There is a hum when the valve actuates but no "flushing" sound or thud of a flapper closing. And NO bubbles.
Third, the control. Admittedly I'm out of my element here but I'm sure others smarter than me can help you out with that. That being said I think you could still do some sort of randomization or at least timer control with 555 timers, relays, etc. Or maybe even Arduino. Again, I don't know much about that so I can't guide you here but I would guess you could use one of those solutions with the actuated ball valves (my valve uses a relay with a timer built in). One thing you will need to pay attention to though is duty cycle so you don't burn out your valves.
I hope that helps and gives you an alternative to consider.
Current music selection: Adelitas Way - Hurt
karimwassef
Active member
Kcress, there are 2 perfectly flat and rigid discs with openings and 2 waterproof pivots needed. That's 4 more parts (3 moving). One joint between the discs, one connecting the moving disc to the shaft. I also don't know how to maintain the disc on disc pressure (seal) over time. I would expect the shaft between them to degrade with repetitive motion and to go from a small acceptable leakage to a continuous flow.
The discs are not a big deal but the joints and seal are much harder. You are significantly more skilled and have better tools. I need to find a simpler solution (plane ticket for kcress?
)
The springs are only linear when they engage. My idea was to position the spring so it only initiates when the distance is small... Creating a non linear step force at the inflection of the exponential force vs. position.
I've worked with gearboxes before to increase torque but they also significantly slow things down (as intended). Getting all the right pieces is also a pain since the shaft stresses can be large (can't glue things).
I was going to mount the top of the actuator to the ceiling joist (stiff) and then a PVC in PVC guide to keep the motion smooth. The hammer is my problem and I am considering building one first to collect data.
The discs are not a big deal but the joints and seal are much harder. You are significantly more skilled and have better tools. I need to find a simpler solution (plane ticket for kcress?
)The springs are only linear when they engage. My idea was to position the spring so it only initiates when the distance is small... Creating a non linear step force at the inflection of the exponential force vs. position.
I've worked with gearboxes before to increase torque but they also significantly slow things down (as intended). Getting all the right pieces is also a pain since the shaft stresses can be large (can't glue things).
I was going to mount the top of the actuator to the ceiling joist (stiff) and then a PVC in PVC guide to keep the motion smooth. The hammer is my problem and I am considering building one first to collect data.
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karimwassef
Active member
Cyclist. I agree.
I don't plan on having a surge reservoir any larger than that, but I am over designing the platform for safety. I'm also adding a surge drain from the DT to the sump and increasing my sump size by 40 gallons.
The Hayward is my backup. Except for the hammer, the actuator was a good idea- simple, cheap, no bubbles. The only reason it is still under consideration is that it is in my garage and speared by a wall from the viewing room. The question is whether the noise will pact the rooms above or the viewing area significantly.
If kcress makes a second butterfly, I might abandon my linear actuator idea altogether.
The idea for the linear solution came from a realization that I don't need a perfect seal for this to work. A leak is an acceptable loss, so why not save $300 with a simple DIY (famous last words).
I don't plan on having a surge reservoir any larger than that, but I am over designing the platform for safety. I'm also adding a surge drain from the DT to the sump and increasing my sump size by 40 gallons.
The Hayward is my backup. Except for the hammer, the actuator was a good idea- simple, cheap, no bubbles. The only reason it is still under consideration is that it is in my garage and speared by a wall from the viewing room. The question is whether the noise will pact the rooms above or the viewing area significantly.
If kcress makes a second butterfly, I might abandon my linear actuator idea altogether.
The idea for the linear solution came from a realization that I don't need a perfect seal for this to work. A leak is an acceptable loss, so why not save $300 with a simple DIY (famous last words).
JonnyQuest
New member
I would recommend having the surge pipe entrance in the horizontal position and then use a gate to regulate the flow (see knife valve). The linear actuator would lift the gate to achieve the surge flow and then close it before the water level got too low so that bubbles would not be introduced into the tank. The gate (acrylic/pvc sheet?) would be located in your surge tank and just be used to significantly block the flow but would not need to be water tight. By having a gate in the vertical position the actuator would not need to overcome the water pressure to open it. You also would not have the water pressure slamming it shut. The actuator would just need to overcome the friction caused by the water pressure pushing against the gate. By adjusting the speed of the gate closing you could eliminate a water hammer from occurring. I never understood why expensive valves were used when it really doesn't matter if there is some leakage of the surge tank while it is being filled by the pump. The only issue would be if the power went out, the surge tank will completely empty but as long as you account for it, it shouldn't be a problem.
karimwassef
Active member
jonny,
do you have an off the shelf sumbersible valve that'll work?
same question for the vertical weber concept. Is there a pre-existing part?
do you have an off the shelf sumbersible valve that'll work?
same question for the vertical weber concept. Is there a pre-existing part?
karimwassef
Active member
how about using a 2" pvc gate valve (or knife valve) and cross-sectioning it after the gate, then drilling out the screw that raises the gate.. then replace that with the shaft connected to the linear actuator?
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karimwassef
Active member
<a href="http://s1062.beta.photobucket.com/user/karimwassef/library/Photobucket%20Desktop%20-%20T00749910" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/Photobucket%20Desktop%20-%20T00749910/surge_zps110c3f42.jpg" border="0" alt="Photobucket"/></a>
Gorgok
New member
Instead of cutting up a fine control valve you could get the slam shut kind already made from these guys: http://flexpvc.com/cart/agora.cgi?product=PVC-Valves-Gate
Only thing you would need to do is connect the shaft to the actuator and then use an actuator that doesn't quite slam it shut =D.
Only thing you would need to do is connect the shaft to the actuator and then use an actuator that doesn't quite slam it shut =D.
karimwassef
Active member
That's who I was looking at for my gate valves but I thought these blade valves have steel shafts? I'll have to call to find out.
BeanAnimal
Premium Member
Why does any valve need to fully seal?
Lets assume a 70 gallon surge (I saw that number above somewhere)
If your "fill" pump does 2000, GPH (33 GPM) then a loose fitting valve (stopper with a bypass port) that leaks 10 GPM means that the tank will fill at a rate of 23 GPM, or in 3 minutes. The valve will never "slam" shut, as the bypass is high enough to prevent the water hammer or slamming. This should be easy enough to contruct with a linear actuater and a DIY stopper that is raised and lowered into the pipe or a concentric pipe and valve (DIY leaky ball valve) that rotates inside of it. When the ports match up, full flow is achieved. When they don't the system leaks a bit.
Lets assume a 70 gallon surge (I saw that number above somewhere)
If your "fill" pump does 2000, GPH (33 GPM) then a loose fitting valve (stopper with a bypass port) that leaks 10 GPM means that the tank will fill at a rate of 23 GPM, or in 3 minutes. The valve will never "slam" shut, as the bypass is high enough to prevent the water hammer or slamming. This should be easy enough to contruct with a linear actuater and a DIY stopper that is raised and lowered into the pipe or a concentric pipe and valve (DIY leaky ball valve) that rotates inside of it. When the ports match up, full flow is achieved. When they don't the system leaks a bit.
JonnyQuest
New member
I was thinking of a gate out of acrylic which is in an slot or a "C" to hold it in place. Think of a guillotine in which an actuator lifts the blade. In your case everything would be made from plastics. This would need to be custom built. I didn't mean to imply you need a knife valve, but just to show concept. I assume a knife/gate valve would have much more friction since it is designed for a complete seal. In your case it would be better to have leakage and less friction to reduce the load on the actuator.
Since you are using a reasonably large pipe (for aquariums) I would suggest putting a vortex breaker to prevent the pipe from sucking air when the water level starts to get low. You can worry about that after it is built to see if one actually forms. You could also put an elbow on the entrance to the gate so that it is facing down to reduce the potential of a vortex forming.
You could use the same concept with the exit pipe in the vertical position and a rotating gate. Think of a circular plate with a 2" hole in it (entire hole in a quadrant). Therefore the radius of the circle would need to be at least 2.5 in. to allow a 2" circle to be cut in it. Rotate open and the hole lines up with the pipe opening. Rotate closed and the plate is solid and therefore drastically reducing the flow. I think Bean was referring to a ball with a hole instead of a circular plate with a hole. However this would be a circular motion instead of linear.
I assume you will add a straight piece of pipe to submerge your fill line from your pump to reduce aeration and noise into the surge tank.
Since you are using a reasonably large pipe (for aquariums) I would suggest putting a vortex breaker to prevent the pipe from sucking air when the water level starts to get low. You can worry about that after it is built to see if one actually forms. You could also put an elbow on the entrance to the gate so that it is facing down to reduce the potential of a vortex forming.
You could use the same concept with the exit pipe in the vertical position and a rotating gate. Think of a circular plate with a 2" hole in it (entire hole in a quadrant). Therefore the radius of the circle would need to be at least 2.5 in. to allow a 2" circle to be cut in it. Rotate open and the hole lines up with the pipe opening. Rotate closed and the plate is solid and therefore drastically reducing the flow. I think Bean was referring to a ball with a hole instead of a circular plate with a hole. However this would be a circular motion instead of linear.
I assume you will add a straight piece of pipe to submerge your fill line from your pump to reduce aeration and noise into the surge tank.
karimwassef
Active member
I thought that as the plug is lowered, the water flowing through the shrinking opening would create a low pressure zone that pulls the plug down even harder causing a hammer/slam.
Is this incorrect?
Is this incorrect?
Steveb
Premium Member
What about something like this? PVC knife valve - push/pull via the linear actuator?
2" valve $16.18
http://stores.drainageproducts.us/-strse-623/Valterra-knife-gate-valves/Detail.bok
duh what gorgok said in post 33...
2" valve $16.18
http://stores.drainageproducts.us/-strse-623/Valterra-knife-gate-valves/Detail.bok
duh what gorgok said in post 33...
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karimwassef
Active member
I want to open quickly but I see no reason why I can't slow down the closing if possible. I thought the low pressure would force the valve closed regardless of the actuator.
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