Ball valve needs to be on the outlet side
Yes for sure! That's why it's called a pump and not a suck...easy way to remember fwiw
Ball valve needs to be on the outlet side
The mag drive isn't so much the reason they can be throttled as the centrifugal impeller part. The mag drive pumps aren't decoupling when they are throttled, the impeller are just thrashing the product. That said, controlling the speed is a much more elegant solution, and doesn't beat up your product (wort) as severely. This can be done using PWM controllers for the March/Chugger AC pumps as well these DC ones, or even a cheaper TRIAC based speed controller for the AC powered pumps.Because these are 12vdc it would be simple to use a voltage regulator to control the speed of the pump. Since they are not magnetic drive I probably wouldn't adjust the flow with a ball valve.
Except that the pot would need to dissipate much more power than a stir plate pot for a muffin fan.Great idea! A simple inline potentiometer like the ones used on the diy stir plates might do the trick.
PWM speed controllers pulse at much higher freqs than you are stating, and appear continuously variable. PWM also gives much more range of speed (low end) for pumps/fans than varying the voltage, and are the preferred speed control solution for these applications (for DC and single phase AC, at least). They are also easier on the motor.Pulse Width Modulation (PWM) controls by changing duty cycle between full-on and full-off states. It s the best solution to control something like a heating element which is difficult to put into a controllable intermediary state.
Using PWM with a pump would mean having the pump start and stop for varying lengths of time (for example, on for one second and then off for 9 seconds out of a 10 second period).
If these motors have a flow rate proportional to voltage applied, that would be a better way to control them - this way you could have a variable and continuous flow rate rather than the repeated on-and-off interrupted flow you would get with PWM.
For anyone who has one of these pump, the easy way to check if they will support variable speed would be to put a potentiometer (variable resistor) in the circuit and check if the pump flow decreased as the potentiometer is dialed to higher resistance (less voltage to the pump). You could also just hook it up to a single 1.5V battery (or 2 1.5s in series to make 3V) and see if it pumps but at a lower flow rate...
-fafrd
The simple TRIAC based speed controllers (ceiling fan controllers) will work well with the AC pumps, but the speed range will be less than an AC PWM controller. WalterAtMarchPumps has a few posts on the topic.Since these are DC (direct current) and not AC (alternating current) a simple speed controller will work. You cannot do this with AC motors because it changes the wavelength of the power and it throws the timing off in the motor.
PWM is the preferred choice, even for the March/Chugger pumps, though I am not sure if you are talking about a brushless DC March pump. I haven't looked into those, but I would be surprised if PWM wasn't the preferred choice for those as well.People are controlling these things by PWM instead of diverting the flow. Whether that's the right thing to do, I don't really know, but it is not what is recommended for the March pump which is brushless.
I got the black pump in today. I can say already, just from loosely screwing on a few pieces that the inlet and outlet threads seem different. I easily got 3-4 threads on the outlet, but maybe 1-1.5 on the inlet before meeting resistance. This could just be a production quality problem as well.
My pump (the little brown one) is 1/2" BSP. 1/2" NPT and 1/2" BSP are more or less compatible. The thread pitch is the same as NPT but there is no taper. NPT and BSP female fittings both screw on and seal with PTFE tape without any problems. The NPT fittings screw on about 4 turns, the BSP fittings 1 or 2.
The black topsflo pump that can be bought on eBay or from www.greatbreweh.com comes in 1/2 inch NPT. Mine came in last week and works great! I currently have a 9 volt adapter hooked up to it but I've ordered a 12 volt for a little more strength.
Just to make sure I understand, a 1/2" NPT female will screw farther onto a 1/2" BSP male than a 1/2" BSP female, right?
If so, I guess that means that the very ends of the male nipples/pipes match and the NPT threads start tapering to be shallower and shallower, where the BSP threads do not.
So the biggest problem is than a BSP female will not thread well onto an NPT male, is that right?
thanks,
-fafrd
Aaaauuuugggghhhhh!!!!
I was getting ready to put my camlocks on and dropped my pump off the workbench, breaking off the outlet. I did what any redneck would do and JB welded it back on but don't want to use it for my beer now. If it holds I'll wire it up and give it a test with water to see how she goes. Maybe keep it for a conical cooler pump or something.
Aaaauuuugggghhhhh!!!!
I was getting ready to put my camlocks on and dropped my pump off the workbench, breaking off the outlet. I did what any redneck would do and JB welded it back on but don't want to use it for my beer now. If it holds I'll wire it up and give it a test with water to see how she goes. Maybe keep it for a conical cooler pump or something.
Just received the black pump and took the cover off the impeller area to inspect things. The plastic impeller seems fine, but when you pull the shaft out there is a plastic spacer and then an exposed magnet that drive the shaft. The entire shaft/ impeller assembly seems like it will be in contact with whatever gets pumped. Seems like it could be sanitized easily enough, but what concerns should I have with the magnet touching water and/ or wort? The pump seems solid overall, but the exposed magnet has me a little worried.
A couple of people have dismantled little brown pumps after they went kaputt and found little bits of grain down inside the impeller by the magnet. They are not 100% hygenic in that respect.
Is there a easy way to make this pump run on ac.
I have no idea of the beige pumps and whether they have coated magnets or not - the Canadian pumps apparently do (now).
adriedel said:Could i just run it to my drill battery?
Could i just run it to my drill battery?
IslandLizard said:I've been following this thread out of curiosity and your vid shows it all at work. Excellent!
That little black pump may have enough power (flow/head) to serve its intended purpose just fine, and that makes it a very good deal.
In comparison, a March 809 has a lot more power, and in certain applications too much. I mounted a valved recirculation loop, which also prevents most cavitation problems.
Well, here's the "test" on the little black Chinese pump. It isn't ideal since I JB welded it back together, so it was a little smaller of an outlet, and I didn't use tape, so there was a small leak.
160 water. In the video I'm holding it at about 48". I measured 2 gal/min at 40" head. This is running off a 12v 2.5a power source.
http://youtu.be/UPUtPO2qI9s
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