March pump frustration - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > March pump frustration

Reply
 
Thread Tools
Old 04-30-2012, 03:21 AM   #1
ReeseAllen
 
ReeseAllen's Avatar
Recipes 
 
Sep 2009
Seattle
Posts: 368
Liked 4 Times on 4 Posts



I'm trying to get my new brewstand running and have run into an issue with my march pump. I got the pump from a coworker who bought a bunch of homebrew gear but never got into the hobby, and it seems to work fine. I have mounted it with the motor axis horizontal and the inlet/outlet horizontal, with the outlet higher than the inlet. I've mounted it under a table, so I had to flip the pump head 180 degrees to keep the outlet higher than the inlet.

The first picture I've attached shows my kettle connected to the inlet and the outlet connected to a hose that's slung over the edge of my MLT. I used it in this configuration to successfully pump 4 gallons of hot water into the MLT in preparation for mashing.

After I pumped the hot water into the MLT and turned off the pump, I spent about an hour screwing around with some thermometers and during that time, the temperature dropped well below my strike temp. "No problem," I said to myself, "I'll just reverse the hoses, pump a gallon or two back up into the kettle, and fire up the burner for a few minutes. Boy, this pump sure is great."

The second picture shows how I plumbed the MLT outlet into the pump inlet, and the pump outlet to the kettle. I opened up the valve on the MLT, the valve on the kettle, and the valve on the pump outlet. Very little water flowed from the MLT down to the pump. It was as if I had a stuck sparge, or had pinched the hose shut near the pump inlet. I had expected the tube leading from the MLT to the pump inlet to quickly fill with water, but lots of air remained in both lines. I turned the pump on and although it appeared to fill the lines with water, it failed to pump any water up into the kettle.

With the pump still on, I disconnected the hose from the kettle and dropped the free end below the height of the pump. Quickly, the pump primed itself, blasted some air bubbles out of the hose, and started shooting a healthy geyser of hot water onto the ground. Lifting the free end of the hose back up to the kettle level, it continued to blast lots of water all over the place. So, clearly disconnecting the hose and dropping it below the pump for a second cleared up whatever was wrong. Obviously, this isn't a long term solution.

I can't figure out why this is happening and it's quite frustrating. I'm a mechanical engineer (which makes it extra frustrating, I'm supposed to be the expert, dammit) so feel free to go as technical as you want if you've got advice to offer. It seems to me that there is no good reason why it would work one way and not the other, considering both vessels are located well above the pump head, and the pump outlet is definitely higher than the inlet which should allow it to clear any air bubbles. Do I need some kind of bleeder valve? Is the orientation of my pump wrong?
Click image for larger version

Name:	IMG_20120429_170652.jpg
Views:	1737
Size:	96.6 KB
ID:	59452   Click image for larger version

Name:	IMG_20120429_194020.jpg
Views:	1648
Size:	88.1 KB
ID:	59453  

 
Reply With Quote
Old 04-30-2012, 03:39 AM   #2
l3asturd
 
l3asturd's Avatar
Recipes 
 
Dec 2011
Visalia, CA
Posts: 461
Liked 10 Times on 8 Posts


Your outlet in the second picture is not providing a path for the air to escape. The air acutally gets the the highest point in before turning downward, which in this case is your pump. If you can orientate the pump so that the outlet is facing up and not allow the outlet hose to sag below the pump the air should escape and liquid should flow.

Notice in your first picture the outlet hose doesn't sag below the pump and it works. I would try that. Another option would be to put a tee on your outlet side and just bleed out the air like you mentioned, but you still wouldn't want the hose to sag below the pump.

outside92129 Likes This 
Reply With Quote
Old 04-30-2012, 04:15 AM   #3
Bobby_M
Vendor and Brewer
HBT_SPONSOR.png
 
Bobby_M's Avatar
Recipes 
 
Aug 2006
Whitehouse Station, NJ
Posts: 23,330
Liked 1765 Times on 1122 Posts


Exactly right. Air has to have an easy escape from the pump head in order for liquid to flood into it. When you dropped the outlet hose down, the water that was in it pulled a vacuum on the pump and evacuated the air.
__________________
Welcome to BrewHardware.com. I love you.
New Stirplates are IN!
Chugger Pumps, Pump Kits, Camlocks, Sightglasses, Clear USA made Silicone Tubing, RIMS, Electric Install Parts, etc.

 
Reply With Quote
Old 04-30-2012, 06:08 AM   #4
beermonkey50
Recipes 
 
Dec 2010
Cape Town, South Africa
Posts: 15

also add a ball valve to the pump discharge. Mount the pump vertically. Using the valve bleed off any air to prime the pump. start the pump with the valve closed then open slowly to the required flow

 
Reply With Quote
Old 04-30-2012, 11:06 AM   #5
Hammy71
Senior Member
HBT_SUPPORTER.png
 
Hammy71's Avatar
Recipes 
 
Sep 2008
, Maryland, The Tax Me State
Posts: 5,899
Liked 531 Times on 404 Posts


Quote:
Originally Posted by l3asturd View Post
Your outlet in the second picture is not providing a path for the air to escape. The air acutally get's the the highest point in before turning downward, which in this case is your pump. If you can orientate the pump so that the outlet is facing up and not allow the outlet hose to sag below the pump the air should escape and liquid should flow.

Notice in your first picture the outlet hose doesn't sag below the pump and it works. I would try that. Another option would be to put a tee on your outlet side and just bleed out the air like you mentioned, but you still wouldn't want the hose to sag below the pump.
Good advice. As a side note, you don't have to remove the whole pump to re-orient it. The motor can stay where it is. Simply remove the four screws from the front of the pump. Turn the pump head and reinstall the screws.

 
Reply With Quote
Old 05-01-2012, 03:00 AM   #6
SamuraiSquirrel
 
SamuraiSquirrel's Avatar
Recipes 
 
Jun 2009
Aurora, IL
Posts: 583
Liked 10 Times on 10 Posts


Just adding a bleeder valve will make life 100 times easier. I wouldnt use a pump without the bleeder valve....... i tried once it was an extremely frustrating brew day.

I have found that orientation of the pump head is not that important. Both ways prime and maintain prime just fine assuming you get the input line flooded.

Maybe if you dont add the bleeder valve it matters more???? Not sure.

I have it mounted horizontally like you have shown and havent had any issues since adding a bleeder valve.
__________________
Up next: Kolsch, Alpha Squirrel, Tripel rebrew, Witbier

Currently Fermenting: Charlie Sheen (barleywine)

Kegged: Tiger Blood IPA, Irish Red, Strict Observance Tripel

Bottled: Dry Stout, Pliny the ..... Squirrel?, Cream Ale

 
Reply With Quote
Old 05-01-2012, 03:06 AM   #7
ekjohns
Recipes 
 
May 2009
IL
Posts: 1,405
Liked 22 Times on 20 Posts


Easiest fix would be to simply lift the hose up above the pump. Someone already mentioned it bug its worth repeating. On My set up I lift the hose till I get it flowing then I'm done.

 
Reply With Quote
Old 05-01-2012, 03:19 AM   #8
IrregularPulse
Hobby Collector
HBT_LIFETIMESUPPORTER.png
 
IrregularPulse's Avatar
Recipes 
 
Nov 2007
Posts: 51,440
Liked 3511 Times on 3325 Posts


Out of all the pump threads I've read, I really think this one is the simplest about just getting to the point of what 99% of people's problems are with pumps. Plain and simple. Good answers guys.
__________________
Tap Room Hobo

I should have stuck to four fingers in Vegas.

 
Reply With Quote
Old 05-01-2012, 10:50 AM   #9
Rbeckett
 
Rbeckett's Avatar
Recipes 
 
Dec 2011
Bronson, Fl
Posts: 995
Liked 70 Times on 49 Posts


A T fitting in the inlet and outlet s of the pump will ease priming to the point of simplicity. I planned this into the overall design and ran the two lines into another T so they combined and could be routed to the drain. No sense having hot sticky water all over the area youre trying to work in. The reason I did it to both sides of the pump is to allow me to bleed the in line, then bleed the out line and minimize waste and time. I used the clear silicone heavy wall tube from Austin Brew supply so I can see exactly what I am doing and again minimize waste. It's very easy to plumb the two T's and related ball valves and will cost arount 20 bucks with brass ball valves and stainless T's. Hope this helps.
Wheelchair Bob
__________________
What do you mean "no Kidneys"???, WTF now I gotta drink less beer...
Join the Automation sub forum in Electric brewing for a discussion of components and control systems. I did!!!!

 
Reply With Quote
Old 05-02-2012, 03:33 AM   #10
ReeseAllen
 
ReeseAllen's Avatar
Recipes 
 
Sep 2009
Seattle
Posts: 368
Liked 4 Times on 4 Posts


Thanks for the responses, everybody. I tested it out and I was able to get it to work properly first try by holding the hoses such that the pump is not at a high point in the circuit. I will probably install a bleeder valve as well, as it seems like the more I search around, the more I find that people are using them.

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Breast pump to replace march pump? instapman Equipment/Sanitation 69 03-21-2012 07:30 PM
March pump losing prime when running pump wide open rockytoptim Equipment/Sanitation 12 09-05-2011 01:42 AM
Dual purpose March Pump as a Rain Barrel Pump nanotigerbrewer Equipment/Sanitation 6 12-01-2010 08:18 PM
March pump wont pump high temperatures. above 190... rshosted Equipment/Sanitation 17 07-12-2010 09:05 PM
How high can a March Pump--pump? jlosbor Equipment/Sanitation 18 07-02-2010 03:13 PM


Forum Jump