Chugger Pump inlet style

I've been looking @ purchasing one of the SS head pumps from them. I see all sorts of images on their site for a center inlet version of the pump.

My question to those of you who have both center inlet & the other inlet type (I guess side by side or top over bottom... not sure what to call it): What has been your experience with both styles? Is there a significant advantage for the center inlet? Is it worth it to wait until chugger comes out with the center inlet version?

I'm not really in a hurry, but I haven't heard when they are actually releasing them either.

What are the advantages/disadvantages of each version? From what I've read on the forums & product descriptions the center inlet has fewer cavitation problems & is easier to prime.

I am also interested since the SS chugger pump is so affordable. Considering how many priming problems people had with march pumps due to orientation, I would like to hear how people orient their chugger pumps.

Has anyone used an auto air purge valve with the pump? I see pictures of march pumps with them and it couldnt hurt to have one on a chugger pump, right?

Edit for fat thumbs on iphone

The website is teasing me with all the center inlet images. I know that much.

i only know on the march pumps that the "center inlet" versions offer a slightly increased flow rate over the side inlet model, apparently. that isnt necessarily related to the placement of the inlet though, could just be coincidence.

the basic design of the pump is the same for either orientation. they are all magnetic drive impeller pumps, so the fluid is dumped into the center of the impellar and the centrifical force pushes the fluid to the edge of the housing and exits the "out" port. all of these pumps dump the fluid into the center of the impellar. the only difference between a side input and a center input is that the center goes directly into the impellar, whereas the side input has a 90 degree bend before it dumps into the same area.

so theoretically, that 90 degree bend is where you would get restriction, and would be the only reason to use a "center inlet" over a "side inlet" pump. (how much "real world" difference you would see is debatable)

The center inlet style pumps will have just over 1/2gpm more on the low speed pumps and just over 1gpm more then the inline style on the HS versions due to two things: First is what audger stated. The inline style forces the fluid to take a 90* bend before entering the pump. And it take another 90* when it gets whipped to the outside by the impeller... Second is the Center inlet style has a bigger ID then the inline style. The inline style has an opening of just under 1/2" where the center inlet style has an inlet opening of just over 9/16.

-Walter

WalterAtMarchPump said:

The center inlet style pumps will have just over 1/2gpm more on the low speed pumps and just over 1gpm more then the inline style on the HS versions due to two things: First is what audger stated. The inline style forces the fluid to take a 90* bend before entering the pump. And it take another 90* when it gets whipped to the outside by the impeller... Second is the Center inlet style has a bigger ID then the inline style. The inline style has an opening of just under 1/2" where the center inlet style has an inlet opening of just over 9/16.

-Walter

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If I'm not overly concerned about that bonus .5-1gpm, are all things fairly equal? What about cavitation? Is that less likely with center? Is priming easier?

As long as the inlet side of the pump has a good size line feeding it, (1/2" ID or bigger) neither one should have priming or cavitation issues assuming there are no other restrictions due to elbows, or valves etc that may be smaller then the ID of the line you are using.

-Walter

Does orientation make a significant difference? I see some setups with inlet on one side, output on the other an others that are vertical.

I'm also guessing that you end up with a bit extra wort loss that must be accounted for when the inlet stops draining.

I have the inline version and priming has never been an issue. The only issue has been at near boiling temps the pump looses prime. So far it hasn't ruined any brew days (16+). Once the wert gets < 180F it works fine. I bought mine last December, old style.

kds1398 said:

Does orientation make a significant difference? I see some setups with inlet on one side, output on the other an others that are vertical.

I'm also guessing that you end up with a bit extra wort loss that must be accounted for when the inlet stops draining.

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Well, I keep telling everyone that calls me that the outlet needs to be at the highest point to let all the air out of the pump head. If you kept the pump as is right out of the box, and placed it flat on a table in front of you, you would see the outlet is slightly higher then the pump body. You can clock the pump head every 90* to rotate the pump head if you wanted to mount the motor in a weird location. But just keep the outlet at the highest point. If you have long lines with a lot of slack in them then clock the pump head so the outlet is pointing straight up to the ceiling.
The next issue most brewers face is the lines running from the pump to the pot they are transferring to. If you have too much line, and you have a downwards dip before it goes up to the pot, then as you open the line and beer floods the pump head it will shoot through the pump and start to fill the output line. If you have that dip, and enough liquid gets in there, it can create an air trap situation between the pump head and the liquid sitting inside that low spot in the outlet line. Depending on how much head pressure you have, it may or may not be able to work all the air out of the pump head....and if not, when you go and start the pump up it will cavitate. Sometimes, if there is only small amounts of air in there, it will pass it and pump as normal...other times you may need to stop the pump...let the air rise to the top and start it up again.

-Walter

Walter, do you guys have a clear 809 pump housing you can take a video of it cavitating during various mounting positions? That would really show people what is happening...

clearwaterbrewer said:

Walter, do you guys have a clear 809 pump housing you can take a video of it cavitating during various mounting positions? That would really show people what is happening...

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I dont have any in clear that would work. We do make a #2 pump head in clear but its only for demo purposes for our sales guys when they go into new potential accounts. The clear pumps are not meant to actually pump any liquids through them. I will brainstorm a bit and see if i can maybe modify an 809-PL housing with a clear plexy cover somehow. May still not work but i may be able to fill it up with liuid and show how air gets trapped inside the pump head.

-Walter

Digging up an old thread but figured why start a new one. I understand the differences between the center inlet and inline versions. I'm still not sure which to get. If I'm using 1/2" ID silicone tubing, does it matter that the center inlet is bigger? In general is the center inlet superior to the inline version?

summerofgeorge said:

Digging up an old thread but figured why start a new one. I understand the differences between the center inlet and inline versions. I'm still not sure which to get. If I'm using 1/2" ID silicone tubing, does it matter that the center inlet is bigger? In general is the center inlet superior to the inline version?

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I just bought the center inlet chugger, it should arrive today. I'm using 1/2" ID sillicone on both sides. Allegedly the center inlet style are easier to prime/prevent cavitation issues. I don't think it's necessarily superior, more of a personal preference. All my kettle/mlt outlets are 1/2" so there was no point to using 3/4" tubing anyway.

Kal (http://theelectricbrewery.com/pumps) uses the march center inlet pumps with 1/2" tubing & doesn't seem to note any issues.

Theres really only one advantage that the center inlet style pump has over the inline version....and that is that the liquid takes one less turn before it gets inside the pump. So you have a straight shot from the tank to the pump before it has to take a 90* turn to exit the pump.
The inline version it has to take a 90* turn just to enter the pump then take another 90 to exit.....so its almost making a square U-turn in some respects....

In the end it just comes down to how you want to plumb the pump....most go for the inline version due to it being more compact on the face side....(you dont have anything sticking out that you can hit as you walk by)....me personaly, i like the center inlet better, but thats due to the fact that when i hook up a pump, im doing it on my test rig and its just easier.

From a fluid dynamics perspective, center inlet is better if you can design your system so your upstream piping is inline (or a gentle transition) to the inlet of the pump. With a relatively straight inlet, you will achieve fully developed flow which is beneficial to reduce potential cavitation (decrease inlet side pressure drop), decrease overall system head loss, decrease power consumption and increase the pumps maximum flowrate.

A centrifugal pump (March/Chugger) by design functions with inlet at a 90° angle to the center of the impeller. The impeller then spins the fluid into the volute and eventually forces it to the outlet. A centrifugal pump naturally creates a 90° turn. By adding an additional 90° to the inlet, there is no added benefit other than potential routing convenience. If possible, I would purchase and design for center inlet pumps.

Most of these issues are minimal with a fractional horsepower pump (1/20 hp). However, If you ever get into larger designs with pumps ranging from 5-500 hp, every 90° elbow you can reduce in your system can result in drastic head reduction which consequently draws much less energy from your pump. This can result in large energy and $$$ savings. As wise engineer once advised me, use the 90° of the pump to your advantage and design your piping system around it!

yeqmaster said:

From a fluid dynamics perspective, center inlet is better if you can design your system so your upstream piping is inline (or a gentle transition) to the inlet of the pump. With a relatively straight inlet, you will achieve fully developed flow which is beneficial to reduce potential cavitation (decrease inlet side pressure drop), decrease overall system head loss, decrease power consumption and increase the pumps maximum flowrate.

A centrifugal pump (March/Chugger) by design functions with inlet at a 90° angle to the center of the impeller. The impeller then spins the fluid into the volute and eventually forces it to the outlet. A centrifugal pump naturally creates a 90° turn. By adding an additional 90° to the inlet, there is no added benefit other than potential routing convenience. If possible, I would purchase and design for center inlet pumps.

Most of these issues are minimal with a fractional horsepower pump (1/20 hp). However, If you ever get into larger designs with pumps ranging from 5-500 hp, every 90° elbow you can reduce in your system can result in drastic head reduction which consequently draws much less energy from your pump. This can result in large energy and $$$ savings. As wise engineer once advised me, use the 90° of the pump to your advantage and design your piping system around it!

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I've attached some pics from the system I am putting together with a Chugger center inlet, which of these orientations should I go with? I was leaning towards #4, pump head above motor (vertical), but the above reply got me thinking. Would it be better to get rid of the 90 degree bend before the inlet and just have the pump sticking straight out of the side? I haven't built my stand yet, so I can pretty much do whatever works best now. I know this may have been answered before, but a google search didn't seem to turn up exactly what I was looking for.

#1 or #3

Thanks Bobby. I guess I will get rid of the 90 degree s well and build my stand around that. BTW, I just ordered one of your 1/4" compression bulkheads and I can't wait to get it so I can finish this build! Thanks for everything you do for us in the way of advice as well.

Bobby_M said:

#1 or #3

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Why not #4?

The pump manuals tell you to keep the motor shaft horizontal

GJOCONNELL said:

Why not #4?

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PeteNMA said:

The pump manuals tell you to keep the motor shaft horizontal

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I would think it has something to do with how easy it would be to get liquid dripping into the motor if it were vertical up or down too.