How high can a March Pump--pump?
 

I'm using 3/8 inch tubing, (if that makes any difference). Can't seem to get much flow above a 3 foot lift. I've shortened the tubing as much as possible but it appears that the most productive flow is 3 ft or less. Is this normal?

I had high hopes that I could pump hot water up to my HLT which is 6 ft above the pump. No way was that happening. Then I tried pumping to my mash tun, which is about four ft. Nothing doing.

It appears I have spent about $350.00 for pump, tubing, and quick disconnects to pump hot wort through my CF chiller. Whoopee.:(

... and all that fail is completely related to not getting the pump primed.

Max height is 12 ft. Should flow 5 gal/min at 4 ft with 1/2" tubing.

March 809-HS Performance Curve

Thanks for the replys. I'm sure I have the pump primed, I opened up all valves and let it flow downhill for a while before turning the pump on. It pumps great as long as the tubes are not raised up too high. The 3/8 tubing may be my problem.

From experience, 3/8" plumbing on a March suxors...

The small 3/8" tubing is the problem. Replace with larger tubing and keep all tubing as short as is practical, especially on the suction side of the pump. Maintain a positive suction head and the more the better.

I'm using 5/8" ID tubing throughout my system and I pump to an elevated HLT just as you are trying to do. I can pump 12 gallons up more than 6 feet in about three minutes or maybe less. I haven't timed it exactly, so that's only a rough estimate, but it's fairly fast.

You may have trouble moving liquids to any significant height if it's much above 200 F. This will vary substantially depending on specific system configurations, but these pumps are more prone to cavitating at higher temperatures. Having positive suction head makes it a lot easier and faster.

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What he said.

Put an air bleed valve like this and your problem will be solved.
http://img165.imageshack.us/img165/164/img145611.jpg

Pat

What is the deal with all of the air bleed valves I have seen lately? I just drop the OUT line to the same level as my IN liquid and it automatically pushes all the air out, then I connect the hose. Takes about 5 seconds.

I timed mine this morning, 4 gal/min with a 3' rise. 1/2" ID tubing

I just open a valve it takes two seconds.