Will This Damage My Pump?

[sparkeee277]

Does anybody have any experience with pumping wort from the mash tun to the boil kettle through the lower valve? I'm building a AG rig with a chiller and pump, and am wondering if I need to add a upper valve on the boil kettle. I'm worried that if I'm filling the boil kettle from the bottom up the back pressure will kill the pump. Any ideas? Thanks in advance guys......

 

[Brettomomyces]

You can always just lay the hose over the top and drape it inside when you're transferring. I added an upper port for recirc/whirlpooling but you don't need to.

 

[wardens355]

That is fine. The higher the level in the kettle, the less flow you will get, but it won't hurt your pump.

Edit: If you haven't used a pump before, or are unfamiliar with centrifugal pumps, the more critical things to remember are to make sure the pump is primed before use (filled with liquid/no air accumulated in the suction line or pump head), that there is as little obstruction as possible in the suction run (pipe/tubing and valves feeding the pump), and that you never operate with a suction valve closed. You can technically operate a centrifugal pump with a discharge valve closed, which is called the 'dead head' condition, as long as you shut the pump off before the liquid temperature gets too high. If you are interested in learning about pumps there are plenty of sites online. This one has a centrifugal pump section:

Pump Types

 

[OleGoatBrewing]

I have a chugger and push liquid up though grains in my mash or BK without any issues. I usually listen to how hard the pump is working to gauge if I'm "abusing" it. No issues.

 

[Bobby_M]

Physics says that draping a hose over the top of the pot puts more head pressure on the pump than pumping into the lower valve. Think about how high the pump has to lift the liquid. Of course if the draped hose is long enough to reach back to the bottom, the head would be about equal.

No, the amount of liquid in the pot doesn't matter.

 

[Big-H]

Does anybody have any experience with pumping wort from the mash tun to the boil kettle through the lower valve? I'm building a AG rig with a chiller and pump, and am wondering if I need to add a upper valve on the boil kettle. I'm worried that if I'm filling the boil kettle from the bottom up the back pressure will kill the pump. Any ideas? Thanks in advance guys......

I don't know if you are using gas or electric to boil but heres something else to think about.

I use a Blichmann boil kettle with a propane burner. I have pumped the wort through the lower valve to fill the kettle and my Chugger pump worked fine. The reason I do NOT do this anymore is that unless you follow up with water at the end to rinse the valve, you have wort trapped in the three piece valve that gets "cooked" "burned" "scorched" during the boil. It gets baked into the valve and is a nasty surprise when you try to transfer or pump to the chiller.

I pump over the side now to keep the valve clean, not because the pump couldn't handle it.

 

[Hammy71]

I pump from my MLT into the bottom valve on my kettle every time. No worries on the pump. Once I'm done transferring I spray Star San into the open end of the valve. A 60 minute boil will kill any other potential 'baddies' in the valve assembly. Never had any gunk getting into fermenter. Once again, no worries.

 

[dmcman73]

Does anybody have any experience with pumping wort from the mash tun to the boil kettle through the lower valve? I'm building a AG rig with a chiller and pump, and am wondering if I need to add a upper valve on the boil kettle. I'm worried that if I'm filling the boil kettle from the bottom up the back pressure will kill the pump. Any ideas? Thanks in advance guys......

Some brewers with conicals fill their conical fermenters this way. They will pump the cool wort from the lower valve on their brew kettle into the drain valve on the conical, same thing with what you're wanting to do.

Two important thing on these pumps is to remember:

1. Make sure they are primed prior to running them
2. Never restrict the flow of liquid on the input side, only restrict the flow on the output side. If you have a valve on your Mash tun or kettle going into the pump, that valve should always stay wide open. To slow the rate of flow, add a valve on the output side of the pump and use that to restrict flow.

 

[sparkeee277]

Wow, you all had awesome responses, I really appreciate it. This is my first pump so the advice is well taken. Especially the priming and restricting the flow on the output side only. I'll post a picture of the rig when it's done, it will be a few months though..... Thanks again!

 

[Indian_villager]

Does anybody have any experience with pumping wort from the mash tun to the boil kettle through the lower valve? I'm building a AG rig with a chiller and pump, and am wondering if I need to add a upper valve on the boil kettle. I'm worried that if I'm filling the boil kettle from the bottom up the back pressure will kill the pump. Any ideas? Thanks in advance guys......

You'll be fine. Just look at the difference between the height of the bottom of your tun (lowest point) to the full level of your kettle (top point) look at this number and compare to the TDH value. If your value is lower than the TDH you are good to go.

 

[raouliii]

Physics says that draping a hose over the top of the pot puts more head pressure on the pump than pumping into the lower valve. Think about how high the pump has to lift the liquid. Of course if the draped hose is long enough to reach back to the bottom, the head would be about equal.

No, the amount of liquid in the pot doesn't matter.

Not to be argumentative, but to add to a discussion on an interesting topic:
The head pressure should be directly related to the weight of the fluid above the pump. The pressure at the bottom drain of the boil kettle will increase as the depth of the liquid increases. Thereby presenting an increasing head pressure to the pump. Since the diameter of the boil kettle is many times the diameter of the pump output hose, this should quickly create a higher head pressure than the essentially fixed head pressure of simply draping the hose over the top, or using a upper inlet. The head pressure using a draped hose would only initially be greater, until the point at which the kettle fluid volume becomes greater than the volume in the draped hose.

Or am I missing something?

EDIT: I WAS MISSING SOMETHING. PLEASE IGNORE THE ABOVE RAMBLINGS.

 

[wardens355]

Not to be argumentative, but to add to a discussion on an interesting topic:
The head pressure should be directly related to the weight of the fluid above the pump. The pressure at the bottom drain of the boil kettle will increase as the depth of the liquid increases. Thereby presenting an increasing head pressure to the pump. Since the diameter of the boil kettle is many times the diameter of the pump output hose, this should quickly create a higher head pressure than the essentially fixed head pressure of simply draping the hose over the top, or using a upper inlet. The head pressure using a draped hose would only initially be greater, until the point at which the kettle fluid volume becomes greater than the volume in the draped hose.

Or am I missing something?

You are misunderstanding hydrostatic head. It has nothing to do with volume, only height of liquid. So you can pump into a kettle with 2 feet of water, or flop the tubing into the kettle so it discharges 2 feet from the bottom of the kettle. The hydrostatic pressure is 2 feet in both instances.

Fundamentals of Hydraulics: Pressure

Also, if your upper kettle valve is higher than the liquid surface in the kettle, it will actually require more energy (have higher hydrostatic pressure) to move the liquid than a valve that discharges below the liquid surface.

 

[raouliii]

You are misunderstanding hydrostatic head. It has nothing to do with volume, only height of liquid. So you can pump into a kettle with 2 feet of water, or flop the tubing into the kettle so it discharges 2 feet from the bottom of the kettle. The hydrostatic pressure is 2 feet in both instances.

Fundamentals of Hydraulics: Pressure

Also, if your upper kettle valve is higher than the liquid surface in the kettle, it will actually require more energy (have higher hydrostatic pressure) to move the liquid than a valve that discharges below the liquid surface.

Thanks. I stand corrected. Learning something new everyday is moving in a positive direction in life.

 

[truebe]

Don't worry that's one of those big unintuitive concepts that trips everyone up when they learn about it.

 

[BPal75]

Interesting about not restricting input side flow. I have not had a pump for very long but didn't realize this. For those that whirlpool then settle, how do you run wort through your chiller without disturbing the trub/hop cone? I figured by restricting the flow out of the kettle (the input side of the pump) I would suck up less disturbed trub/hop debris. But apparently this will shorten the life of my pump?

 

[Alt]

By restricting the flow at the valve on the out port of the pump, you reduce the flow of wort moving out of the kettle. Think about this way, if you close the valve completely the pump isn't moving any wort (except inside the pump head). The draw from the kettle will equal the flow out the control valve.

 

[dkennedy]

Interesting about not restricting input side flow. I have not had a pump for very long but didn't realize this. For those that whirlpool then settle, how do you run wort through your chiller without disturbing the trub/hop cone? I figured by restricting the flow out of the kettle (the input side of the pump) I would suck up less disturbed trub/hop debris. But apparently this will shorten the life of my pump?

Without cracking open one of my very dusty hydraulics texts, you want to avoid this because it changes the pressure dynamic in the impeller of your pump. In short, yes it's hard on your pump.

In a previous life I got to play with fire trucks for a living. In that context, you didn't gate your supply unless it was the last option (and there are a lot more options on a pumper). In addition to the obvious (more water = better, in that context), you could also create cavitation within the pump, which can destroy a pump. I heard someone cavitate a pump hard once, it sounded like they had sucked gravel into the pump. I'm not sure if hot wort is less likely to cavitate, but it's habit by now to run my suction wide open.

I'd move your suction out towards the edge of the kettle, and angle it. I have a torpedo/bazooka screen in my kettle, which isn't tolerating hop bombs very well, but will likely try a hop spider rather than fashion a dip tube (already have the screen). Others who whirlpool may have better techniques.

 

[dmcman73]

Also, by restrictions the flow on the input you make the pump work harder.
Just to note, the chugger and march pumps are not shaft driven impellers, they are magnetic. If you remove the pump head from the motor you'll notice that there is no shaft going into the housing, just a big old magnet inside the motor that spins. So if you need to remove the pump head or rotate it, you don't have to worry about a shaft.

 

[BPal75]

This has been very informative! Thanks everyone

 

[sparkeee277]

So I brewed this last weekend with my new chugger and it was awesome. I didn't realize how much easier and enjoyable brewing would be using a pump. Thanks again everybody for sharing your knowledge!

 

[augiedoggy]

I just wanted to add my experiences for what its worth.
I have found that restricting the input flow of the magnetic drive pumps also can damage them as it causes them to heat up more that normal and the walls of the pump around the magnet to warp. My experiences of this are from years of owning aquariums and having the filter media become partially plugged on pumps and powerheads. I would thing a pump designed to handle boiling liquids would be more tolerant of this so it may be more of a non issue with these but after reading of the failures of the smaller DC magnetic pumps designed for up to 220degrees when restricting with ball valves I decided it would be easier on my 12 and 24v DC pumps to control the speed electronically with PWM controllers.
Its only been a year and I have just upgraded two of my pumps from 12v to stronger 24v versions (due to new rims setup) but the pwm control has worked perfect for me to control flow and I have never had a stuck sparge with them yet as I start the pump flow very slow and work the speed up slowly to "set the grainbed filter".

 

[wardens355]

I just wanted to add my experiences for what its worth.
I have found that restricting the input flow of the magnetic drive pumps also can damage them as it causes them to heat up more that normal and the walls of the pump around the magnet to warp. My experiences of this are from years of owning aquariums and having the filter media become partially plugged on pumps and powerheads. I would thing a pump designed to handle boiling liquids would be more tolerant of this so it may be more of a non issue with these but after reading of the failures of the smaller DC magnetic pumps designed for up to 220degrees when restricting with ball valves I decided it would be easier on my 12 and 24v DC pumps to control the speed electronically with PWM controllers.
Its only been a year and I have just upgraded two of my pumps from 12v to stronger 24v versions (due to new rims setup) but the pwm control has worked perfect for me to control flow and I have never had a stuck sparge with them yet as I start the pump flow very slow and work the speed up slowly to "set the grainbed filter".

You can also just use the discharge valve to modulate the flow. Anyone that tries to control flow with an inlet valve is going to damage their pump. It's not a question of poor pump design, it's just the way it is.

 

[augiedoggy]

You can also just use the discharge valve to modulate the flow. Anyone that tries to control flow with an inlet valve is going to damage their pump. It's not a question of poor pump design, it's just the way it is.

Yes Very true but this still causes the pump to fight harder and heat up more vs pwm control. Kind of like slowing a truck down by putting a 10,000lb trailer behind it vs just letting up on the gas..... Which one will cause more wear and tear on the truck?.. That was my point I guess.

 

[PJM]

I pump from my MLT into the bottom valve on my kettle every time. No worries on the pump. Once I'm done transferring I spray Star San into the open end of the valve. A 60 minute boil will kill any other potential 'baddies' in the valve assembly. Never had any gunk getting into fermenter. Once again, no worries.

I just started thinking about this on my last brew session. I have been using a pump on my last 5 brews and I had never considered this before. But I got an infection on the batch before which made be consider this issue.

First, I have a two piece ball valve which I NOW open and run a brush through after each use. I also leave the valve open after cleaning to make sure it dries inside the valve. Do you guys think I need to do anything else to assure that the ball valve stays clean? Do you guys with 3 piece valves break them down to clean them and if so, how often?

Second, do you really think that the ball valve (the portion on the outside of the keg anyway) gets hot enough to sanitize whatever might be left in there after you pump wort into the kettle through it? I don't use a heat shield on my ball valve because it doesn't get that hot. So I'm wondering if it gets hot enough to sanitize whatever fluid is left inside it. I guess you could recirculate a little bit right at the end of the boil in order to make certain that the valve gets sanitized by the hot wort.

Thanks for your responses and sorry if this is a bit off topic.

PJM

 

[dmcman73]

Yes Very true but this still causes the pump to fight harder and heat up more vs pwm control. Kind of like slowing a truck down by putting a 10,000lb trailer behind it vs just letting up on the gas..... Which one will cause more wear and tear on the truck?.. That was my point I guess.

Not with these pumps. The impellers on these pumps are magnetic driven, they are not attached directly to a shaft on the motor. Basically the motor spins a big magnet around the housing so if flow is restricted on the output, the impeller can slow down without causing strain on the motor itself.

 

[augiedoggy]

Not with these pumps. The impellers on these pumps are magnetic driven, they are not attached directly to a shaft on the motor. Basically the motor spins a big magnet around the housing so if flow is restricted on the output, the impeller can slow down without causing strain on the motor itself.

Yes I believe it still generates more heat which is what I was talking about when I mentioned all the magnetic ones I have seen heat up and warp when the filters became partially plugged and restricted flow. in my aquariums and reef tank, Yes it was restricted on the input side and not the output but I dont believe that makes a difference since the plastic actually melted/warped and caused the magnets to seize in some cases.... It is still putting more resistance on the coil that drives the magnet in the pump which I believe = more heat from what I've seen. why else would they heat up and warp? they operate like a big turbine of alternator only instead of producing they are consuming energy...both of them generate different amounts of heat based upon the "load" put on thier magnetic field right?

 

[wardens355]

Yes it was restricted on the input side and not the output but I dont believe that makes a difference since the plastic actually melted/warped and caused the magnets to seize in some cases

I don't want to sound crass, but believing and being correct are two different things. You have just admitted that the suction was restricted. This is what makes a pump work harder and cavitate, or have other issues that cause overheating.

Variable speed control is impractical for a homebrew wort pump, in my opinion. Throttling a discharge valve simply moves the pump back on its curve, and unless you are at or close to dead head on the curve, I don't see a problem. In fact, this is the recommended method of operation according to March Pump. Granted you waste some energy by throttling flow, but for such a small pump it is negligible. Also, there shouldn't be overheating issues unless you dead head the pump or make restrictions on the suction side. Personally, I want my pump running at full speed to keep any hop or grain particles from accumulating in the pump head.

 

[wardens355]

First, I have a two piece ball valve which I NOW open and run a brush through after each use. I also leave the valve open after cleaning to make sure it dries inside the valve. Do you guys think I need to do anything else to assure that the ball valve stays clean? Do you guys with 3 piece valves break them down to clean them and if so, how often?

Second, do you really think that the ball valve (the portion on the outside of the keg anyway) gets hot enough to sanitize whatever might be left in there after you pump wort into the kettle through it? I don't use a heat shield on my ball valve because it doesn't get that hot. So I'm wondering if it gets hot enough to sanitize whatever fluid is left inside it. I guess you could recirculate a little bit right at the end of the boil in order to make certain that the valve gets sanitized by the hot wort.

I typically break my valves down every several batches and clean out gunk or spoiled wort that was trapped in there. However, I keep the valves and pump clean by putting 2 gallons or so of hot PBW solution in my kettle after a brew day and recirculate it through my kettle valves. I also run hot water through the valves and open and close them to flush out anything that is caught behind the ball. Remember to not exercise a suction valve during pumping!

I sanitize my ball valves by recirculating boiling wort through them 10 minutes before the end of boil. If you do that, make sure to throttle the discharge valve until you see little or no bubbles in the suction tubing. If you don't want to do that, or only have one kettle valve, I would just remove the valve the night before to clean/sanitize it before use. It may get hot enough during the boil, but I like to cover all bases.

Edit: You will also want to clean/sanitize your pump. Recirculating boiling wort works for that as well.

 

[AnOldUR]

Don't worry that's one of those big unintuitive concepts that trips everyone up when they learn about it.

Getting back to pumping through the bottom port, help an old guy understand this in simple terms. In my eyes, if pumping from MLT to kettle on a single tier system, once the volume in the kettle exceeds the volume in the MLT, gravity is pushing fluid back on the pump and increasing the work required. Just as in the early part of transfer, gravity is assisting the flow by pushing wort out the valve. With no pump, the two vessles are trying to reach equilibrium. By pumping higher into the kettle (draping the hose or a higher kettle port) it seems there'd be a more consistent and manageable load. The only work the pump has to do is offsetting the height distance between the current level in the MLT and the highest level of the hose. So, you're saying my intuition is wrong?

 

[augiedoggy]

I don't want to sound crass, but believing and being correct are two different things. You have just admitted that the suction was restricted. This is what makes a pump work harder and cavitate, or have other issues that cause overheating.

Variable speed control is impractical for a homebrew wort pump, in my opinion. Throttling a discharge valve simply moves the pump back on its curve, and unless you are at or close to dead head on the curve, I don't see a problem. In fact, this is the recommended method of operation according to March Pump. Granted you waste some energy by throttling flow, but for such a small pump it is negligible. Also, there shouldn't be overheating issues unless you dead head the pump or make restrictions on the suction side. Personally, I want my pump running at full speed to keep any hop or grain particles from accumulating in the pump head.

I get your point and did admit the restriction was on the input side because of this possibility but since a $6 pwm speed controller costs less and is more percise than a decent stainless ball valve I beg to differ on it being impractical for homebrewing... at least with dc pumps, its easier to create set points with a knob and replicate specific speeds without guessing as well... just as many consider using electric of pid for homebrewing We all have our different requirements and opinions of what is and isnt justified I guess...
I believe (again opinion at this point) that increasing mechanical restrictions and force can cause more wear to a pump than simply reducing force and controlling how hard it is being asked to work directly. resistance=heat and less efficiency And that makes practical sense to me regardless of what evidence I bring to the table...

 

[AnOldUR]

I look at using a speed control on a magnetic drive pump like pedaling a bicycle up a hill. Throttling back on the output side is like gearing down. The magnetic drive does the same work, only the impeller spins slower. By lowering the power to the pump, you’re staying in the same gear, but moving slower because you’re too weak.

 

[wardens355]

Getting back to pumping through the bottom port, help an old guy understand this in simple terms. In my eyes, if pumping from MLT to kettle on a single tier system, once the volume in the kettle exceeds the volume in the MLT, gravity is pushing fluid back on the pump and increasing the work required. Just as in the early part of transfer, gravity is assisting the flow by pushing wort out the valve. With no pump, the two vessles are trying to reach equilibrium. By pumping higher into the kettle (draping the hose or a higher kettle port) it seems there'd be a more consistent and manageable load. The only work the pump has to do is offsetting the height distance between the current level in the MLT and the highest level of the hose.

The discharge hose is filled with liquid to the discharge point, so that is the pressure on the pump. If the kettle is filled below that point and you are connected below the liquid surface, there is less pressure on the pump. And you are mistaken that once the volume in the kettle exceeds the MLT volume it will push back to the pump. It is the height, not the volume, that drives the hydraulic gradient. You are correct that the flow may be more consistent with a fixed, free discharge point above the liquid surface, but the flow rate will be lower overall.

 

[DNKDUKE]

I pump from my MLT into the bottom valve on my kettle every time. No worries on the pump. Once I'm done transferring I spray Star San into the open end of the valve. A 60 minute boil will kill any other potential 'baddies' in the valve assembly. Never had any gunk getting into fermenter. Once again, no worries.

It may "kill any other baddies" but those baddies can still potentially give you off flavors.
I like BIG-H's reasoning and believe that that is exactly where I picked up some off flavors on a couple batches....FWIW.

 

[augiedoggy]

It may "kill any other baddies" but those baddies can still potentially give you off flavors.
I like BIG-H's reasoning and believe that that is exactly where I picked up some off flavors on a couple batches....FWIW.

I would think it would take quite a bit of gunk to give 5 gallons of beer a noticeable off flavor? Not saying its not possible just that I think a tiny bit in a ball valve would have to be really nasty stuff to do so and if someone flushes the system out after every brew that wouldnt be likely to happen...

 

[AnOldUR]

And you are mistaken that once the volume in the kettle exceeds the MLT volume it will push back to the pump. It is the height, not the volume, that drives the hydraulic gradient.

Guess I made an a$$ of me by assuming that the vessels were the same size (like mine), so the height would be the same at equal volume. (Not to mention how grain absorbsion factors in.)

Regardless, isn't it hydraulic pressure that increases the load on the pump as the kettle level increases beyond that of the MLT? Isn't that hydraulic pressure from gravity much greater from a full kettle than in a half inch diameter hose?

 

[AnOldUR]

I would think it would take quite a bit of gunk to give 5 gallons of beer a noticeable off flavor?...

I have to agree. And since I always drain the first pint or more into a pitcher before sending the rest to my fermenter, it becomes even less of a problem.

 

[wardens355]

Guess I made an a$$ of me by assuming that the vessels were the same size (like mine), so the height would be the same at equal volume. (Not to mention how grain absorbsion factors in.)

Regardless, isn't it hydraulic pressure that increases the load on the pump as the kettle level increases beyond that of the MLT? Isn't that hydraulic pressure from gravity much greater from a full kettle than in a half inch diameter hose?

No. Imagine you have a kettle filled with water, and a tube connected to the bottom couple. Raise the tube up and the water level in the tube is going to be the same as in the kettle. If it were as you describe it, the level of water in the tube would be higher (I assure you this does not happen for an open top, non-pressurized tank). I think I posted a link earlier in this thread that goes to a basic hydraulics page. I suggest reading that if you want to better understand.

 

[dmcman73]

Yes I believe it still generates more heat which is what I was talking about when I mentioned all the magnetic ones I have seen heat up and warp when the filters became partially plugged and restricted flow. in my aquariums and reef tank, Yes it was restricted on the input side and not the output but I dont believe that makes a difference since the plastic actually melted/warped and caused the magnets to seize in some cases.... It is still putting more resistance on the coil that drives the magnet in the pump which I believe = more heat from what I've seen. why else would they heat up and warp? they operate like a big turbine of alternator only instead of producing they are consuming energy...both of them generate different amounts of heat based upon the "load" put on thier magnetic field right?

It makes all the difference in the world! The fluid is acting as a coolant and lubrication for the pump. Restrict the flow on the input and you just restricted the lubricating factor the liquid provides and the cooling of it as well because you are essentially starving the pump, this creates a lot of heat.

Restrict it on the output side and the pump head will always be filled 100% with fluid (if it was primed properly) and will have that required lubrication and the liquid will keep the pump as cool as the liquid is.

These motors were built to handle the amount of force you apply to them by restricting the liquid flow on the output side and the magnet drive prevents the motor from stalling and over heating like a shaft driven pump would do.

 

[AnOldUR]

No. Imagine . . .

So, I was confusing pounds with pounds per square inch. PSI is determined by depth not volume. Makes sense when I think about it.