Rover Pump M-20

[Belter]

Anyone know how this compares to a chugger? I like the fact that it self primes. It comes in at a similar price.

[Belter]

Ok now the chuggers have all gone I'm very interested in the pump. Anyone else have any experience or reviews of this pump? I like the self priming option

[darkonnis]

Obviously I haven't tried it but I must say I like the look of it. Very substantial, looks pretty damn solid and the noise... well I like things that are noisy as you can hear when its working well (or isn't) and thus disconnect it if it starts having a fit. *shrug* just me perhaps. Only thing I can't get away with is the price and I suspect the little solar pumps will do the job for me just nicely.

[barneey]

Wow that thing is noisy, I thought the March Pumps were bad http://www.youtube.com/watch?v=Mzjpg6WUMqA Have you tried mounting the thing on a piece of noise suppression sheet?

[Kev888]

I like the self priming option

One small difference I didn't realise is that it does self prime exactly as you say, and it does also lift/suck to a significant height too, but it doesn't self prime 'to' its lifting height (which is only achieved when already wet/primed). Not a biggie in many situations but it was something that 'nearly' caught me out with my own intentions for it.

Cheers
kev

[Belter]

Does self priming mean you can run it dry? If so why aren't all pumps like that. Or... Should I say is there a benefit of a pump not being self priming.

[greenhouseuk]

Wow that thing is noisy, I thought the March Pumps were bad http://www.youtube.com/watch?v=Mzjpg6WUMqA Have you tried mounting the thing on a piece of noise suppression sheet?

Subject: Rover Pump M-20

I didn't think it was loud!
This is actually a temporary set-up, I did have a knackered drill pump that made a loud and disconcerting banging - so this is heaven.
Tomorrow I an reconfiguring the pipe work to take a much lower power pump situated beneath the kettle which has 3m head so will still be able to negotiate chiller. New youtube video to come....!
At that point I sell this set-up and the upgrade begins with thermo pots, 30 plate chiller and the Rover Pump (maybe with sound deadening).

[greenhouseuk]

Does self priming mean you can run it dry? If so why aren't all pumps like that. Or... Should I say is there a benefit of a pump not being self priming.

You can run this dry - there is stainless steel driveshaft, however, I would not want to do this indefinitely.

I think price has a lot to do with the non self-priming pumps being popular, it is not rocket science to create a setup where the pump sits "below" any and all of the vessels. In my instance I use gravity for moving water or wort from lauter tun and mash tun, but if you have a single storey setup with RIMS you probably need 3 pumps at least.

[darkonnis]

Price is the factor for running pumps dry - Pumps which run dry suffer overheating and seizing. Seizing occurs because in many cases the liquid is acting as a lubricant to some extent.

As for being able to "draw" liquids and self prime - The impeller needs machining to a high degree of accuracy with the internal walls, this means when it starts running it physically pushes gas out and creates a partial vacuum on the side its drawing from. This is what pulls the liquid up. Cheaper pumps are not machined to this level because the higher wear and tear it induces means more expensive materials are needed and thus the pump is no longer cheap.
Thats part of it atleast, I'm no pump engineer so there is more to it I suspect but thats about the bones of it. Partial vapour systems (gas+liquid) need the mixture to be made either gas or liquid before you can do too much with it usually unless you use something like a turbo expander coupled with a phase separator (again, not something I know too much about)

[Kev888]

Does self priming mean you can run it dry? If so why aren't all pumps like that. Or... Should I say is there a benefit of a pump not being self priming.

self-priming and (truly) run-dry are different really, self-priming pumps can run dry but not 'necessarily' for very long without wearing excessively and/or overheating unless they're designed for it.

To self prime, a pump must be able to suck air, which if its normally needed for pumping thicker fluids can involve some design compromises. The rotors can clear the impeller housing less tightly if its not self priming, meaning potentially less wear, less noise, fewer expansion issues and so on. Also if the pump is designed to go beyond that and provide suction/lift in normal/running use then it should be designed to avoid excessive cavitation under low pressure at the inlet, so again some potential efficiency compromises.

Its not necessarily related, but in a home brew pump I'm yet to find a magnetically driven impeller thats self priming - so at least in the cases I know of this is also connected. Certainly many shaft-drive pumps dislike having their flow restricted so bypass loops are used instead of simple flow restriction; no biggie but mildly extra complexity and sanitation etc. There is also the high-temperature shaft-seal too, dealing with a leak-free seal and expansion etc at brewing temperatures (with food-grade materials), and with the theoretical sanitation concern of a reasonably loose seal.

But ' in practice' these may not be major problems or differences if the design and materials are good and all that. Personally I prefer mag-driven but I'd certainly not say that its a no-brainer in typical home-brewing use.

Cheers
kev

[Belter]

Does self priming mean you can run it dry? If so why aren't all pumps like that. Or... Should I say is there a benefit of a pump not being self priming.

self-priming and (truly) run-dry are different really, self-priming pumps can run dry but not 'necessarily' for very long without wearing excessively and/or overheating unless they're designed for it.

To self prime, a pump must be able to suck air, which if its normally needed for pumping thicker fluids can involve some design compromises. The rotors can clear the impeller housing less tightly if its not self priming, meaning potentially less wear, less noise, fewer expansion issues and so on. Also if the pump is designed to go beyond that and provide suction/lift in normal/running use then it should be designed to avoid excessive cavitation under low pressure at the inlet, so again some potential efficiency compromises.

Its not necessarily related, but in a home brew pump I'm yet to find a magnetically driven impeller thats self priming - so at least in the cases I know of this is also connected. Certainly many shaft-drive pumps dislike having their flow restricted so bypass loops are used instead of simple flow restriction; no biggie but mildly extra complexity and sanitation etc. There is also the high-temperature shaft-seal too, dealing with a leak-free seal and expansion etc at brewing temperatures (with food-grade materials), and with the theoretical sanitation concern of a reasonably loose seal.

But ' in practice' these may not be major problems or differences if the design and materials are good and all that. Personally I prefer mag-driven but I'd certainly not say that its a no-brainer in typical home-brewing use.

Cheers
kev

Excellent. Thanks for the detailed response. Is the pump in question not a Mag drive pump?

[Kev888]

I don't actually have this specific pump, but my understanding is that its shaft driven and that the optional high temperature seal is the one around the shaft entry into the impeller housing.

Like I mentioned, I'm not saying shaft-driven is a problem if done well, and this does look like a very decent pump so please no-one think I'm putting it down.

Cheers
kev

[greenhouseuk]

Does self priming mean you can run it dry? If so why aren't all pumps like that. Or... Should I say is there a benefit of a pump not being self priming.

self-priming and (truly) run-dry are different really, self-priming pumps can run dry but not 'necessarily' for very long without wearing excessively and/or overheating unless they're designed for it.

To self prime, a pump must be able to suck air, which if its normally needed for pumping thicker fluids can involve some design compromises. The rotors can clear the impeller housing less tightly if its not self priming, meaning potentially less wear, less noise, fewer expansion issues and so on. Also if the pump is designed to go beyond that and provide suction/lift in normal/running use then it should be designed to avoid excessive cavitation under low pressure at the inlet, so again some potential efficiency compromises.

Its not necessarily related, but in a home brew pump I'm yet to find a magnetically driven impeller thats self priming - so at least in the cases I know of this is also connected. Certainly many shaft-drive pumps dislike having their flow restricted so bypass loops are used instead of simple flow restriction; no biggie but mildly extra complexity and sanitation etc. There is also the high-temperature shaft-seal too, dealing with a leak-free seal and expansion etc at brewing temperatures (with food-grade materials), and with the theoretical sanitation concern of a reasonably loose seal.

But ' in practice' these may not be major problems or differences if the design and materials are good and all that. Personally I prefer mag-driven but I'd certainly not say that its a no-brainer in typical home-brewing use.

Cheers
kev

Thanks Kev
All pretty much bang-on. The other consideration is filtration, this pump will have less tolerance of larger particles than mag drive pumps, I will be inserting a Y-filter in my setup as a final insurance that the FB is doing its job. (I will have to review whether this is up to the job)