Author Topic: Pump problems  (Read 3012 times)


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Pump problems
« on: November 19, 2016, 12:50:10 PM »

I have recently changed the pipework on my 2 pumps. I have made each line longer to allow for easier connectivity.

I have come to brew today and for some reason the pumps dont seem to work very well. There seems to be a lot of air in the pipes all the time.

When i open the valve on the HLT the water doesnt even flow out when the pump and pipe is connected, however, if i take the pipe connection off and open the valve the water flows out.

Can anyone shed any light on this. Caused me massive issues today.

Offline Oginme

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Re: Pump problems
« Reply #1 on: November 19, 2016, 02:58:46 PM »
How much longer did you make the lines?  Which side of the pump did you lengthen the line on?   If they are too long for the size of the pump, the friction loss in the piping may be too much for the pump to handle and it would either have a hard time overcoming the friction loss on the outlet side or unable to draw enough on the inlet side causing cavitation.
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Re: Pump problems
« Reply #2 on: November 20, 2016, 06:54:31 AM »
Greetings - Oginme summed it up pretty well. Perhaps you can share some pictures of your setup.  Without seeing your particular setup, it's difficult to predict.  Oginme was referring to "head loss". Pumps are designed to deliver a specific GPM at a specific vertical head.  That said, if your tubing is mostly in the horizontal position, than head loss should not be as much of an issue.

Post some pictures so we can have a look.
« Last Edit: November 20, 2016, 07:09:11 AM by KellerBrauer »

Offline twhitaker

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Re: Pump problems
« Reply #3 on: November 21, 2016, 10:18:39 AM »
 Make sure all your connections are airtight, especially INLETS; and optimum configuration allows for an airbleed. As air bubbles flow up, the inlet of the pump should be same level or lower than inlet vessel , lower than the pump outlet and the airbleed valve on the outlet higher. Turn on valves and bleed air out of the pump head before turning it on. If pump action doesnt happen after a few seconds, turn off pump, and rebleed air bubbles. Sometimes you have to move the hosing around to dislodge air bubbles. Once all air is purged liquid will flow.
 Use a smaller 3/8 or 1/4" valve for airbleed at pump head outlet, teed off of outlet line, direct outlet of airbleed to a small pot. You want liquid to flow out before pump is turned on, close airbleed before starting pump. Look for nice solid liquid flow. Any liquid collected can be returned to batch.
Without an airbleed you have to move the airbubbles manually up to the head by raising sections of the inlet and outlet hose and moving them around a bit. Your inlet line should be short as possible. Solid lines definately require an airbleed arrangement. Hot wort , false bottoms screens and bazooka screens create a lot of air lock bubble issues. You should also have a throttle valve just at the pump head outlet to control flow. CHEERS , search byo pump arrangement for pic

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