Pump not priming correctly, causing oxidation?

[h22lude]

Anyone have issues with their pump not priming correctly? I seem to have an issue where my pump won't prime right especially with something else attached to it (like my CFC). My pump is below my kettle and my CFC is on the same level as my kettle. I think I need to let wort run through the pump before attaching my CFC.

What I have noticed is if it isn't fully primed, the pump pushes a lot of air through. If I'm recirculating the wort while chilling, could this cause oxidation? I have been noticing an off flavor in a lot of my beers that I can't explain. I'm wondering if not priming the pump correctly is causing O2 to be pumped into the wort as it is chilled. Obviously good at pitching temp but could it be causing an issue when the wort is just under boiling temp?

 

[hvjackson]

Try opening the valve to your pump about 30 seconds before turning it on. That will let liquid flow and slowly displace the air in the lines.

Priming really has to do only with stuff before the pump. If there is sufficiently liquid flow TO the pump you should not have any priming problems.

What is the overall shape of your layout? Is the liquid just draining out of your CFC via gravity faster than the pump can keep up?

 

[mredge73]

Are you using a priming valve on your pump? If not it will surely help; tie in a Y at the pump outlet and open it to a sanitized pitcher to fill the pump head prior to turning it on.
Hot side aeration is defiantly a thing but I don't fully understand the effects.

 

[schematix]

Hot side aeration is defiantly a thing but I don't fully understand the effects.

There's a whole site devoted to the subject and related topics now.... http://www.********************/

Arguing about oxidation and HSA on HBT is like arguing Judaism vs Islam in Jerusalem.

Here's one way to configure a pump head to make priming easy... also makes draining afterwards simple so you're not dumping hot sticky wort everywhere.

 

[h22lude]

Try opening the valve to your pump about 30 seconds before turning it on. That will let liquid flow and slowly displace the air in the lines.

Priming really has to do only with stuff before the pump. If there is sufficiently liquid flow TO the pump you should not have any priming problems.

What is the overall shape of your layout? Is the liquid just draining out of your CFC via gravity faster than the pump can keep up?

The wort coming from the kettle is the issue. It trickles into the pump and will only fill up half way. There will be wort at the pump but air half way up the tube.

The kettle is on my table. Tubing goes down to the pump then tubing up from the pump to the CFC on the same table.

Are you using a priming valve on your pump? If not it will surely help; tie in a Y at the pump outlet and open it to a sanitized pitcher to fill the pump head prior to turning it on.
Hot side aeration is defiantly a thing but I don't fully understand the effects.

I am not but that is definitely a good idea. It the tubing from the pump to the CFC isn't attached yet, wort will flow through. So I either need a priming valve or let the pump prime without attaching the CFC then attach it after the wort is flowing.

There's a whole site devoted to the subject and related topics now.... http://www.********************/

Arguing about oxidation and HSA on HBT is like arguing Judaism vs Islam in Jerusalem.

Here's one way to configure a pump head to make priming easy... also makes draining afterwards simple so you're not dumping hot sticky wort everywhere.

View attachment 401607

Yeah this is something I may need to do. I also need to attach the pump to my table. Right now it sits on a shelf near the floor. I have to put it on a bucket when I brew. I should attach it to the leg of the table and make a valve like this.

 

[hvjackson]

The wort coming from the kettle is the issue. It trickles into the pump and will only fill up half way. There will be wort at the pump but air half way up the tube.

OK this is a red flag.

You have a blockage or airlock somewhere, either before or after the pump. Are ALL the valves open? Is your CFC chiller clear? (Is it a clogged plate chiller??). The liquid should completely fill the tubing before you turn the pump on. If the liquid hasn't filled the tubing then don't turn the pump on, you risk damaging it by running it dry.

Check the entire plumbing run, from the outlet of your kettle all the way to the end of the hose. Something somewhere is either shut or trapping air and building up pressure so that liquid cannot fill.

You can test this with cold water BTW.

 

[jrcrilly]

The trick is to always open the pump output valve first so the air has a place to go. Then open the ball valve feeding the pump. Wait until the air is gone in the input line, then turn on the pump. Always works here.

 

[stz]

I go via tap on my kettle to Y filter to pump to plate chiller to length of hose which I fill with or recirculate through. What I do is recirculate sanitiser through the whole system through the kettle while mashing in and once I'm ready to start collecting I run the sanitiser into a bucket stopping the tap and pump just before the kettle runs dry. As such everything is already primed with liquid throughout the boil. Gravity will do this alone, but if I want to speed things along I might suck to start a siphon. Once I've finished my boil and I'm ready to start collecting from the kettle or recirculate is I open the tap, start the pump and run to drain or jug until I get wort coming through, then the hose either goes into the kettle or into a sanitised fermenter. I estimate I lose no more than half a pint doing this, though this might not be for everybody.

You should be able to leave your pipe or whatever is on the outlet of your plate chiller or pump at a low level and with the pump off completely prime the entire run with gravity only. If not you've either got insufficient height, a blockage or an air lock somewhere. If you still get air entering the system then you've got a leaky connection. Don't start the pump until it is completely full because quite a few will run with half liquid/half air just spinning the same air around.

 

[h22lude]

OK this is a red flag.

You have a blockage or airlock somewhere, either before or after the pump. Are ALL the valves open? Is your CFC chiller clear? (Is it a clogged plate chiller??). The liquid should completely fill the tubing before you turn the pump on. If the liquid hasn't filled the tubing then don't turn the pump on, you risk damaging it by running it dry.

Check the entire plumbing run, from the outlet of your kettle all the way to the end of the hose. Something somewhere is either shut or trapping air and building up pressure so that liquid cannot fill.

You can test this with cold water BTW.

All valves are opened and everything is clear. I assume air is stopping the flow of wort, I just don't know why. I'd think as long as everything is below the top level of the wort, it should flow. The wort should push the air out of the CFC....but since the pump is hard to prime I guess my assumption is wrong lol I think I just need a priming valve.

The trick is to always open the pump output valve first so the air has a place to go. Then open the ball valve feeding the pump. Wait until the air is gone in the input line, then turn on the pump. Always works here.

I'll give this a try though would it really matter? If the valve feeding the pump is opened the wort would stay in the kettle as the air is blocking it from flowing. Once the pump valve is opened the air should rush out and allow the wort the flow.

 

[h22lude]

There's a whole site devoted to the subject and related topics now.... http://www.********************/

Arguing about oxidation and HSA on HBT is like arguing Judaism vs Islam in Jerusalem.

Here's one way to configure a pump head to make priming easy... also makes draining afterwards simple so you're not dumping hot sticky wort everywhere.

View attachment 401607

I saw the thread you originally posted in with this picture. Originally you had the inlet elbow right at the pump. Why does there need to be a 3" straight pipe at the inlet?

 

[Homercidal]

If the line is clear, and the pump is below the surface of the wort, then it "should" flow into the pump enough to be able to turn the pump on. I struggled for a few batches before realizing that I'd had the OUTPUT of the CFC sitting in the kettle, below the wort level, and the wort itself was blocking the air from being pushed out. As soon as I lifted the hose from the wort, the pump and most of the CFC filled quickly and I was able to turn the pump on.

Apparently there is enough resistance against the flow of air, since the height of the pump is about even with the kettle spigot. I did not have such issues when the pump sat much lower.

 

[h22lude]

If the line is clear, and the pump is below the surface of the wort, then it "should" flow into the pump enough to be able to turn the pump on. I struggled for a few batches before realizing that I'd had the OUTPUT of the CFC sitting in the kettle, below the wort level, and the wort itself was blocking the air from being pushed out. As soon as I lifted the hose from the wort, the pump and most of the CFC filled quickly and I was able to turn the pump on.

Apparently there is enough resistance against the flow of air, since the height of the pump is about even with the kettle spigot. I did not have such issues when the pump sat much lower.

I would think the same thing. My pump is well below my kettle. I wouldn't think the CFC would put resistance on the flow of air but maybe it does.

 

[Homercidal]

Trust me, it does. I was mildly frustrated when I first started using a pump right up until I discovered that little trick. All I ever heard before was to make sure the pump is lower than the kettle.

 

[h22lude]

Trust me, it does. I was mildly frustrated when I first started using a pump right up until I discovered that little trick. All I ever heard before was to make sure the pump is lower than the kettle.

Glad I'm not the only one that had this issue. I thought the same. It makes sense but I guess the laws of physics don't work like that lol

 

[schematix]

I saw the thread you originally posted in with this picture. Originally you had the inlet elbow right at the pump. Why does there need to be a 3" straight pipe at the inlet?

Rule of thumb for pumps is to have a straight section 5-10x the ID of the pipe at the inlet so you have laminar flow.

It might have worked the original way, but a process engineer (designer for pipe/pump/tank/valve systems) i worked with said "hey do whatever you want, but don't complain to me if it doesn't work because i told you so". So i did it that way.

 

[h22lude]

Rule of thumb for pumps is to have a straight section 5-10x the ID of the pipe at the inlet so you have laminar flow.

It might have worked the original way, but a process engineer (designer for pipe/pump/tank/valve systems) i worked with said "hey do whatever you want, but don't complain to me if it doesn't work because i told you so". So i did it that way.

Interesting. I need to find a good way to attach my pump to my brew stand. I'll be copying your design.

What kind of teflon tape did you use? It looks clear.

 

[hvjackson]

A priming/bleed valve might work around the priming problem but you definitely have an unusual restriction of some type and the pump is never going to work well. You need to find out what is wrong.

Try taking the tubing off the pump outlet and blow through it. Can you blow? If not, work your way down until you find the closed valve or restriction.

 

[h22lude]

A priming/bleed valve might work around the priming problem but you definitely have an unusual restriction of some type and the pump is never going to work well. You need to find out what is wrong.

Try taking the tubing off the pump outlet and blow through it. Can you blow? If not, work your way down until you find the closed valve or restriction.

No I'm positive it is just the priming issue. My two tubes are clean and clear. My valve works fine. I take the pump head apart every batch so that is clean and it moves freely.

 

[schematix]

What kind of teflon tape did you use? It looks clear.

It's gray - premium heavy duty teflon tape: https://www.lowes.com/pd/Blue-Hawk-0-6-in-x-21-ft-Plumber-s-Tape/4751307

It's about 5x the cost of the standard issue teflon tape but it has a number of properties that make it attractive:
1. It only takes about 2 wraps vs 10
2. It doesn't collapse on itself. Its pretty thick and firm.
3. If you have to take it apart it doesn't shred into a million tiny pieces. Usually it comes off in 2-3 big pieces but if its been pushed deep into the threads just wrap a paper towel around the threads and twist lefty-loosy and it'll all come out.
4. It changes color to black upon the application of pressure. If you have a sealing issue, find where the tape is gray when you take it apart.
5. The threads slide together smoother than the white stuff, which gets shredded when the connection gets tight.
6. I can't make the white stuff seal a household water pressure connection no matter what i do. This stuff works every time, so i keep it on hand for household projects.

 

[dyqik]

The priming issue is most likely because you have a dip-tube of some kind in the vessel. That creates an airlock at the outlet from the kettle. Air can't flow down through the liquid, either through the pump or out of the dip-tube.

The best bet is to close the outlet valve on the pump, and squeeze the hose to push the air-lock out into the kettle. This will take a few goes - wait 10s between each squeeze for wort to flow down the tube.

 

[h22lude]

The priming issue is most likely because you have a dip-tube of some kind in the vessel. That creates an airlock at the outlet from the kettle. Air can't flow down through the liquid, either through the pump or out of the dip-tube.

The best bet is to close the outlet valve on the pump, and squeeze the hose to push the air-lock out into the kettle. This will take a few goes - wait 10s between each squeeze for wort to flow down the tube.

Interesting. I'll have to check that out. I'm going to test this with plain water tomorrow. I did have a dip tube that went down to the kettle edge but this batch I just had a 90° elbow pointing down. I guess air would still get trapped in that.

 

[dyqik]

Interesting. I'll have to check that out. I'm going to test this with plain water tomorrow. I did have a dip tube that went down to the kettle edge but this batch I just had a 90° elbow pointing down. I guess air would still get trapped in that.

Yeah, a 90° elbow is enough to cause an airlock if the outlet is horizontal.

 

[dyqik]

Just want to show you my solution to airlocks in the kettle/mash-tun outlet caused by diptubes. These are inline thermometers, attached to tees and camlocks that I use to monitor temperatures at the mash-tun outlet with my RIMS system, and at the outlet of the kettle and CFC during chilling. They use the brewhardware compression fittings to grab the probe of the CDN thermometers (would also work with other probes and thermometers). By pulling the probe out, I can let air out of the airlock formed at the outlet valve until some fluid comes out. I probably only lose a tablespoon of fluid that way, and it seems to allow my pumps to prime without issue.

 

[h22lude]

Just want to show you my solution to airlocks in the kettle/mash-tun outlet caused by diptubes. These are inline thermometers, attached to tees and camlocks that I use to monitor temperatures at the mash-tun outlet with my RIMS system, and at the outlet of the kettle and CFC during chilling. They use the brewhardware compression fittings to grab the probe of the CDN thermometers (would also work with other probes and thermometers). By pulling the probe out, I can let air out of the airlock formed at the outlet valve until some fluid comes out. I probably only lose a tablespoon of fluid that way, and it seems to allow my pumps to prime without issue.

View attachment 402397

I actually built something like this for the output of my CFC. I never thought about pulling out the thermo but didn't want wort squirting everywhere. Does it only drip out?

 

[dyqik]

If you pull the thermometer out very carefully, yes. If you pull it all the way out, it runs out. So be careful.

 

[h22lude]

There's a whole site devoted to the subject and related topics now.... http://www.********************/

Arguing about oxidation and HSA on HBT is like arguing Judaism vs Islam in Jerusalem.

Here's one way to configure a pump head to make priming easy... also makes draining afterwards simple so you're not dumping hot sticky wort everywhere.

View attachment 401607

Is there a good way to make this with as little threaded parts as possible? I'm moving everything over to TC. I already have TC element and everything is connected with camlocks. Just trying to make tear down a lot easier to do. I haven't found thin piping. Everything I find seems to be at least 1.5" wide.

 

[BeerAddikt]

The priming issue is most likely because you have a dip-tube of some kind in the vessel. That creates an airlock at the outlet from the kettle. Air can't flow down through the liquid, either through the pump or out of the dip-tube.

The best bet is to close the outlet valve on the pump, and squeeze the hose to push the air-lock out into the kettle. This will take a few goes - wait 10s between each squeeze for wort to flow down the tube.

I think you just pinpointed the issue I've been having when I whirlpool. I have a diptube and I've been tipping my kettle slightly which releases the bubbles but I'm going to try the hose squeezing method. I was so frustrated when I first started using the pump because priming was a PITA. I've figured out my workaround but it can take me a min or two to get it primed properly. I like your idea.

 

[dyqik]

I think you just pinpointed the issue I've been having when I whirlpool. I have a diptube and I've been tipping my kettle slightly which releases the bubbles but I'm going to try the hose squeezing method. I was so frustrated when I first started using the pump because priming was a PITA. I've figured out my workaround but it can take me a min or two to get it primed properly. I like your idea.

The latter method I mentioned with the inline thermometer/bleed valve at the kettle output works much better, btw.