Author Topic: Magnetic VS Peristaltic  (Read 5792 times)

Offline beerocd

  • Senior Brewmaster
  • ******
  • Posts: 1400
    • View Profile
Magnetic VS Peristaltic
« on: November 06, 2009, 09:01:20 PM »
Through indecision, I happen to have both. I know the magnetic is more popular, but I think it's more due to cost. So, I'm soliciting opinions. If you could have either - and cost is not the deciding factor which route would you go?


-OCD
The moral majority, is neither.

Offline tom

  • Senior Brewmaster
  • ******
  • Posts: 1110
  • Denver, CO
    • View Profile
Re: Magnetic VS Peristaltic
« Reply #1 on: November 07, 2009, 09:38:48 AM »
I dont know enough about peristaltics. Do you need special hose? What volume can they pump? Where'd ya get it?
Thanks, Tom
Brew on

Offline beerocd

  • Senior Brewmaster
  • ******
  • Posts: 1400
    • View Profile
Re: Magnetic VS Peristaltic
« Reply #2 on: November 07, 2009, 10:26:28 AM »
The peristaltic can go up to 2.3 litres per minute.It's a Cole-Parmer Masterflex - off ebay for less than the cost of a March pump. So it's slower, but can prime itself and even sit on a shelf above all the kettles.The tubing isn't much worse than others options. You would use silicone, or Tygon. It's variable speed, I can also use it for racking wine and stuff if I really wanted to.

The magnetic pumps I grabbed do about 5 gpm and can take water up to just below boiling, so I wouldn't use it to pump finished wort. They were new, and a really good deal, so now I have a decision to make. 2 of these pumps came out less than a March Pump.

Before you say it, yes I have spent more than the cost of a March pump by now.  ::)
I liked the self priming aspect of the perstaltic - the cheap mag drives are half the cost of the peristaltic.
I will either resell the pumps I don't use - or put together another system and list it on craigslist.

-OCD

The moral majority, is neither.

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11696
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Magnetic VS Peristaltic
« Reply #3 on: November 11, 2009, 01:36:22 PM »
While I'm really happy with my March, the self priming of a peristaltic is a real plus AFAIAC.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline bonjour

  • Administrator
  • Senior Brewmaster
  • *****
  • Posts: 1771
  • Troy, MI, 37mi, 60.9deg AR
    • View Profile
Re: Magnetic VS Peristaltic
« Reply #4 on: November 11, 2009, 02:34:08 PM »
When I was looking at pumps I couldn't see why peristaltic pumps wern't used.  I looked at the flow rates that you wanted to use with brewing on a home scale basis and it seemed to me that the March pumps were always throttled back, either thru valves, tubing size or lift.  The slower flow rates made more sense to me for a homebrew application.

That said the March pumps certainly have been successful in the homebrew application.

Fred
Fred Bonjour
Co-Chair Mashing in Michigan 2014 AHA Conference in Grand Rapids, Michigan
AHA Governing Committee; AHA Conference, Club Support & Web Subcommittees



Everything under 1.100 is a 'session' beer ;)

Offline buckapound

  • 1st Kit
  • *
  • Posts: 1
    • View Profile
Re: Magnetic VS Peristaltic
« Reply #5 on: November 11, 2009, 03:43:58 PM »
Just so we all know what we're talking about, some terminology. The March pumps happen to be magnetically coupled to the motors, which avoids the need tor a seal to keep the liquid out of the motor, but this says nothing about the pump head itself. The Marches and most other common small pumps are centrifugal. These will not self-prime, meaning they need to be below whatever you're pumping and filled with water or they will just sit there and spin--which is usually not too good for them.

In theory, you could magnetically couple the peristaltic pumps, but it doesn't get you anything. The liquid being pumped stays in the tubing and so there are no seals required. They are used in things like heart-lung machines because the inside of a piece of tubing can be made a very sterile place. So, they are good for transferring beer. I have one of the little Cole-Parmer Masterflex pumps that uses hose about 1/4" ID, and it transfers 5 gallons in about 10 minutes or so--acceptable. This is a little too slow for some of my other tasks in a 15-gallon brewery. You do need to use specially engineered tubing, and it isn't cheap. I think I had to buy about $50 worth to be able to use a $15 pump ($500 retail--now how much would you pay?).

There is one additional common small pump, a gear type pump. This works like the oil pump in your car and uses a pair (or three) small gears, and are positive displacement, meaning they will suck a vacuum and are self-priming. They don't like chunks in them, as the small gears mate fairly closely, but I've never had a problem from that. Most of the small ones are magnetically coupled like the small centrifugal ones. Also, stainless heads and they seem to have no trouble with very hot liquids and don't cavitate like centrifugal pumps can with liquids near boiling. Micropump (especially) and Tuthill are the brands to seek out. I like these for most brewery tasks.

--Randy


Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11696
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Magnetic VS Peristaltic
« Reply #6 on: November 11, 2009, 05:07:45 PM »
These will not self-prime, meaning they need to be below whatever you're pumping and filled with water or they will just sit there and spin--which is usually not too good for them.

Randy, I've heard this and believe it.  I'm a relative newbie to pumps...I've only used mine maybe 1/2 a dozen times.  So, can you tell me what kinda "bad juju" will happen if I run my pump dry or umprimed?  I've noticed that if I run my pump to recirculate when the kettle is still boiling I get intermittent air pockets in the line.  That doesn't happen once I shut off the burner.  Will those intermittent air pockets harm my pump?  Should I order some spare parts, just in case?   ;)
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline dbeechum

  • Administrator
  • Brewmaster General
  • *****
  • Posts: 2311
  • Pasadena, CA
    • View Profile
    • Experimental Brewing
Re: Magnetic VS Peristaltic
« Reply #7 on: November 11, 2009, 08:52:40 PM »
So, can you tell me what kinda "bad juju" will happen if I run my pump dry or umprimed? 

Pieces crack and fall apart and spit in your beer while gremlins pee in it.
Drew Beechum - Maltosefalcons.com
- Vote in the AHA GC Election! - http://bit.ly/1aV9GVd  -
-----
Burbling:
Gnome is in the Details
*Experimental Brewing - The Book*
Tap:
Peanut Butter Jelly Time
Tupelo Mead
Farmhouse Brett Saison

Offline beerocd

  • Senior Brewmaster
  • ******
  • Posts: 1400
    • View Profile
Re: Magnetic VS Peristaltic
« Reply #8 on: November 12, 2009, 07:32:54 AM »
I have one of the little Cole-Parmer Masterflex pumps that uses hose about 1/4" ID, and it transfers 5 gallons in about 10 minutes or so--acceptable. This is a little too slow for some of my other tasks in a 15-gallon brewery. You do need to use specially engineered tubing, and it isn't cheap. I think I had to buy about $50 worth to be able to use a $15 pump ($500 retail--now how much would you pay?).
--Randy


You could use smaller sections of hose fitted onto copper or stainless tubes. That way once you need to replace the hose from wearing out on the rollers it's much less $$$. Killer deal you got on the pump!

-OCD
« Last Edit: November 12, 2009, 10:12:10 AM by beerocd »
The moral majority, is neither.

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11696
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Magnetic VS Peristaltic
« Reply #9 on: November 12, 2009, 09:53:53 AM »
So, can you tell me what kinda "bad juju" will happen if I run my pump dry or umprimed? 

Pieces crack and fall apart and spit in your beer while gremlins pee in it.

Peeing gremlins I've dealt with before....no big deal. ;)  So, what happens what the pump then is that impeller pieces break off?
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline bonjour

  • Administrator
  • Senior Brewmaster
  • *****
  • Posts: 1771
  • Troy, MI, 37mi, 60.9deg AR
    • View Profile
Re: Magnetic VS Peristaltic
« Reply #10 on: November 12, 2009, 10:43:58 AM »
So, what happens what the pump then is that impeller pieces break off?
You are an old fart,  remember when the elephant stepped on a Timex?  What time is it?  Time to get a new Timex.

 ;D
Fred
Fred Bonjour
Co-Chair Mashing in Michigan 2014 AHA Conference in Grand Rapids, Michigan
AHA Governing Committee; AHA Conference, Club Support & Web Subcommittees



Everything under 1.100 is a 'session' beer ;)

Offline dbeechum

  • Administrator
  • Brewmaster General
  • *****
  • Posts: 2311
  • Pasadena, CA
    • View Profile
    • Experimental Brewing
Re: Magnetic VS Peristaltic
« Reply #11 on: November 12, 2009, 11:56:10 AM »
Peeing gremlins I've dealt with before....no big deal. ;)  So, what happens what the pump then is that impeller pieces break off?

What Fred said.. time for a new, well not pump, but a new head assembly.
Drew Beechum - Maltosefalcons.com
- Vote in the AHA GC Election! - http://bit.ly/1aV9GVd  -
-----
Burbling:
Gnome is in the Details
*Experimental Brewing - The Book*
Tap:
Peanut Butter Jelly Time
Tupelo Mead
Farmhouse Brett Saison

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11696
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Magnetic VS Peristaltic
« Reply #12 on: November 12, 2009, 11:57:38 AM »
Peeing gremlins I've dealt with before....no big deal. ;)  So, what happens what the pump then is that impeller pieces break off?

What Fred said.. time for a new, well not pump, but a new head assembly.

That's kinda what I figured...any idea how long it takes to self destruct if it runs dry?  A couple seconds?  A couple minutes?  Does anyone get those air pockets when you run still boiling wort through it?  Are those a problem?  Will I ever find true happiness in life???  ;)
« Last Edit: November 12, 2009, 11:59:32 AM by denny »
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe