Newbie Pump Questions

[thelorax121]

Alrighty, so I am in the middle of my second batch on my new single tier and I had a few basic questions on pump usage for those with a little more experience under their belts (I am using a little giant with a ball valve on the outlet port btw).

First, is it bad for the pump to be running with the ball valve in the closed position? It is much easier to do cut the flow this way when transferring to fermenters and the like, but I don't want to mess up the pump. Second, I am using a Xtreme cooler with a 2ft steel braid for a mash tun, and I am wondering if people use their pump to do the vorlauf, and if so how, and for how long, so far I have had mixed results getting clear wort into the kettle, and I am wondering if making a drain manifold and possibly sparge manifold would ease this process. That is all I can think of for the moment, but more questions may come to mind, thanks for the help gang!

 

[klyph]

The magnetic resistance will add a slight amount of strain to the motor, but shouldn't hurt it at all, just make sure your pump is staying cool.

 

[thelorax121]

Is there anything I can do to keep it cool?

 

[zymurgy101]

Is there anything I can do to keep it cool?

Fall is coming! =-)

Provided the head is full of wort (not dry), you should be okay while switching lines, etc. However, like Klyph said, make sure it isn't getting too hot. Put your hand on it; if it feels hot to the touch, then don't keep the valve closed quite as long. It will definitely get warm though. All my Little Giant and Iwaki magnetic drive pumps run warm. The main thing is not to let the head run dry.

 

[thelorax121]

Got it, thanks for the help, I just wanted to make sure I wasn't gonna mess up my new toy Anybody have any feedback on using a pump to vorlauf, and if so at what rate/time?

 

[Catt22]

Got it, thanks for the help, I just wanted to make sure I wasn't gonna mess up my new toy Anybody have any feedback on using a pump to vorlauf, and if so at what rate/time?

Running your LG pump with the outlet valve closed will do it no harm, even for extended periods. It won't overheat either so long as it is not in an enclosed cabinet or box and air flow to it's internal cooling fan is not restricted in any way.

You should be able to do the vorlauf thing easily with your pump. No need to pump fast. Easy does it and this will reduce the chance of compacting the grain bed which could cause a stuck mash. If that should happen, simply stop the pump and give the grain bed a good stir, then continue at a slightly slower rate so that it does not happen again. Normally a few minutes of circulation is sufficient, but just eyeball the wort at the return and use your own judgment. The clarity of the wort at this point has little bearing on the clarity of the finsihed beer. What you really want to do is let the grain bed filter out the large particulates like pieces of grain husk etc. Circulating longer won't do any harm, but there's really nothing to gain once the wort is running clear or mostly so. I used to do the vorlauf manually and about two gallons worth was usually enough and often much less than that. No need to over think the process. It's not that important.

 

[Chemkrafty]

While you won't do any short term harm to your pump, where the valve is located matters. I assume this is a centrifugal and not a positive displacement type pump.

If the valve you close is on the inlet side of the pump, you won't increase line pressure, but you could cause cavitation in the pump which over time will damage the impeller, causing early pump failure. Probably not a large concern though given the way homebrewers use pumps. Also, if your lines are not metal, you could cause them to collapse when you close it as the pump pulls a vacuum on that line.

If the valve is on the outlet side, you are going to deadhead the pump. The pump itself is not harmed by this, however, the system pressure will max out between the valve and the pump and if your system is incapable of handling the pressure, some leaks could occur.

In both cases, there is no flow and so all of the energy is turned into heat energy in the fluid versus transferring that energy into a flowing fluid. The preferred case is a valve located shortly after the outlet of the pump. If you need to cut off flow, you would close this valve. Ideally it will be hard piped to avoid leaks or blowing a line. Again, it is possible that the homebrewing pumps do not generate enough pressure to make a difference though. You can also use this valve to regulate flow.

If you are regulating flow, I would recommend against using a ball valve. They are great for on/off, but suck for control. Use a valve with a knob vs a lever handle as those types are generally going to be more controllable.

 

[Catt22]

While you won't do any short term harm to your pump, where the valve is located matters. I assume this is a centrifugal and not a positive displacement type pump.

If the valve you close is on the inlet side of the pump, you won't increase line pressure, but you could cause cavitation in the pump which over time will damage the impeller, causing early pump failure. Probably not a large concern though given the way homebrewers use pumps. Also, if your lines are not metal, you could cause them to collapse when you close it as the pump pulls a vacuum on that line.

If the valve is on the outlet side, you are going to deadhead the pump. The pump itself is not harmed by this, however, the system pressure will max out between the valve and the pump and if your system is incapable of handling the pressure, some leaks could occur.

In both cases, there is no flow and so all of the energy is turned into heat energy in the fluid versus transferring that energy into a flowing fluid. The preferred case is a valve located shortly after the outlet of the pump. If you need to cut off flow, you would close this valve. Ideally it will be hard piped to avoid leaks or blowing a line. Again, it is possible that the homebrewing pumps do not generate enough pressure to make a difference though. You can also use this valve to regulate flow.

If you are regulating flow, I would recommend against using a ball valve. They are great for on/off, but suck for control. Use a valve with a knob vs a lever handle as those types are generally going to be more controllable.

I generally agree with most of this. The March and Little Giant pumps commonly in use by home brewers don't generate much line pressure, so it is very unlikely that shutting off the flow on the outlet side would result in blowing a hose or causing a leak. We're talking only about 5 or 6 psi, possibly a little more than that, but not a whole lot more. Using a valve on the suction side is never a good idea and there's no reason to set the pump up that way. I also agree that a gate valve works much better than a ball valve for more precise flow control. I made that switch a long time ago and would never consider going back to using a ball valve. I also use a gate valve for flow control from my elevated HLT instead of a ball valve.

Yes, these pumps are centrifugal and not the positive displacement type. I've inadvertently run my pump for hours with the outlet valve completely shut. The LG pump is so quiet that I did not notice that I had forgotten to turn it off. This did no harm to the pump or the motor and it did not get any warmer than it normally does. Closing the outlet valve completely would be no different than exceeding the max pressure head to the point that the flow stopped entirely. IIRC, that's about 12 ft for my LG. You can run them days on end like that without harming the pump or the motor.

 

[Chemkrafty]

Thanks for the info on the homebrewing pumps. I've dealt with industrial pumps and wasn't sure what sort of head these produced...and it seems like there is truly not much to worry about. Eventually I'll get to the point where I have a fun pumping system set up to play with, but I'm not there yet!!

 

[Catt22]

Thanks for the info on the homebrewing pumps. I've dealt with industrial pumps and wasn't sure what sort of head these produced...and it seems like there is truly not much to worry about. Eventually I'll get to the point where I have a fun pumping system set up to play with, but I'm not there yet!!

A pump was one of the best investments in brewing equipment that I have made. I'm sure you will be glad you got one.

Regarding running the pump with the valve fully closed, I've noticed that the motor sounds like it is running with less effort, not more. I think what is happening is that the impeller is simply pushing water around in the volute and not working against the pressure head as it would be if with the valve open. I don't think the mag drive ever un-couples, even with the valve fully closed. I've read where some seem to think that this does happen, but I don't.

 

[funkswing]

Alex,

I tried PM you, but your mailbox is full bro! This is Jon from Athens.

I am getting geared up for another hops order. So, if you are in the need start checking hopsdirect for what you want. Let me know what you are thinking. We should go half-sies on some of the pounds (i.e. noble and warrior).

Jon