Will Magnetic drive pumps freewheel?

[MartinOC]

I'm looking at a LBP (12V) to recirculate my HLT up to sparge temp's & then either:

1. Use the pump to transfer the sparge water to the MLT (possibly throttled via ball valve) on the same level;
2. Have the HLT at a higher level & use gravity to feed to MLT through the pump (switched-off);
3. Change hoses to allow unrestricted gravity-feed to the MLT (ie. not through the LBP).

If I was to go with the 2nd scenario, I'm wondering whether the LBP would freewheel & allow unrestricted gravity flow, or impede it?

Any anecdotal feedback on this?

I'll ask the same question of March 809 pumps (I have one of those too), but I'm intending it for mash recirculation.

 

[GalBrew]

Don't do it Martin,
Get a green Kaixin pump from Keg King or wherever. They are pretty cheap (around $60-70) and are far superior to the LBP. Whether to go utilise gravity or not is neither here nor there. I have a raised HLT but it is all hooked up to a couple of pumps so I can do either or.

Edit: spelling.

 

[Camo6]

Pretty sure they do or atleast have enough clearance not to impede flow dramatically. My LBP and recirc setup on my old biab rig would flow when I disconnected a hose to prime it.


Edit: agree with above. Kaixin for the win!

 

[DJ_L3ThAL]

Not using FTW instead of for the win, reported. (Sorry Martin, had to)

 

[sp0rk]

My Kaixin pump free wheels when it's turned off, I'm sure a LBP would do the same

 

[Sam England]

I use LBP's on my brau clone and sous vide unit and they don't freewheel easily. They appear to kick from one pole to the next when you turn them, but as Camo6 mentioned they do allow some flow past them. I believe the Kaixin style "magnetic drive" pumps work more like a traditional pump with the impeller linked to the motor via magnets like a stir bar on a stir plate and hence will freewheel the motor more easily. The LBP's have a magnet cast into the impeller that is made to spin via the coil around the outside. I've had issues if I don't soak and run the LBP's after each use in clean water as the wort gets into this area and gums up the pump. If you're only using it for water like on my sous vide unit, they are great little pumps.

Cheers,
BB

 

[MartinOC]

Hmmm..... If I didn't already have the March 809 (bought 10+ years ago & still in it's box :unsure, I'd definitely be looking at a Kaixin for mash recirc. duties.

I'm really only looking at the LBP for strike/sparge recirculation/transfer duties (I've seen Yob's rig in operation, which gave me the inspiration), so it's not like it's going to get a hard-time.

I pulled my original (5V, 3-level, gravity-only) rig apart many years ago, but now I'm re-thinking/re-building & trying to incorporate all these new-fangled electronical thingamajigs into the equation.

It would seem from the above responses that my thinking is correct, so a mag-drive won't get in the way if it's only used for water. Worst-case scenario, I can always turn the pump on if the gravity-feed pressure reduces towards the end of the sparge (I historically fly-sparge, BTW).

 

[Camo6]

Not using FTW instead of for the win, reported. (Sorry Martin, had to)

Humph. You Gen Y's an' yer fancy abbreviations.
And stay offa my lawn you pesky kids!!

 

[Yob]

As you have seen, my HLT LBP is on a separate "circuit" to my HLT outlet, I am starting to think about hooking the 809 (stainless steel head, thanks chugger) to pump from HLT to MT and do the recirculation on the HEX. (keeping my 24v LBP spare)

So a bit of both worlds.. Betcha it takes me 12 months though coz it's working so damned well atm I don't really wanna mess with it.

You know you're gunna have to Brew something soon Martin... People will start to talk

 

[MartinOC]

For some reason, I'm unable to quote..???

Yob,

Yeah, I understand your use of the 12V LBP to recirculate in the HLT to avoid stratification & you draw from it from a different outlet. I was just thinking to use the same outlet & same pump, to save on having to drill extra holes etc.

Quite frankly, I don't GAFF what people think of me - that's their business. I've made prize-winners in the past & (if I can be arsed entering them in competitions) will do so again. I've brewed a few times this year (mostly a complete clusterfuck, but drinkable), but I can do better.

That's what I'm aiming-at: Overall Efficiency.

I learned the 7 "P"'s from my time in the military: Proper Preparation & Planning Prevents Piss-Poor Performance.

I also learned that no plan survives first-contact with the enemy.......

 

[Yob]

You are doing it right I think Martin, thinking through the issues in advance, things and kinks are often highlighted and ironed out in the use of the system (well that's how it worked for me anyway)

Do let me know when you're gunna give it a spin, happy to pop round and give a hand/take photos/point and laugh

 

[MartinOC]

For shits & giggles, you can take a place in the queue, pal !!!

 

[pk.sax]

At this rate even I'd get back into it quicker than you Martin.

 

[Sam England]

Martin, is there any reason why you can't put a T on the inlet side to the pump so that you can gravity drain past the pump without having to drain through it? I have a similar set-up on my Braumeister clone so that I can easily drain at the end of the brew.

 

[TheWiggman]

In regards to your original question, yes any pump will impede flow (because there will always be some sort of friction loss there). The LBP's definitely don't freewheel with low pressure. How much it will impede will vary. I think on a 3V system where your static head is SFA you're not going to overcome the magnetic stickiness like mentioned above. My anecdotal evidence is you probably lose half your max possible flow.

 

[MartinOC]

Martin, is there any reason why you can't put a T on the inlet side to the pump so that you can gravity drain past the pump without having to drain through it?

Thanks, BB - Great idea!....and now, something ELSE to go on the shopping list!

 

[Parks]

My March pump definitely freewheels - I can hear it going like a rocket when I'm back-flushing from the tap.