Discuss: Pump Priming

[flyangler18]

What is stopping the liquid from going to the right side of the TEE where the relief valve and copper tubing is?

The needle valve. When it's closed, no liquid can make it out the bleeder tube.

 

[IrregularPulse]

I was a little more patient last friday, and opened the kettle valve to let the liquid flow via gravity to the pump before turning it on. I had an instant prime...so maybe I was just overreacting in my OP. But to answer your question, the march pump and recirculating whilrpool IC setup was an awesome upgrade. I LOVE my pump (used it three times so far).

Cool. I 'll probably still add one in the future. I would also use it for recirculating through a CFC. But I've also found one pass with gravity chilled my wort down to pitching temps as well. Does the pump just allow you to do it faster?
I have many more things before worrying about a pump. Such as ingredients.Trying to break my Hobby Equipment Whoring this year. Not going to allow myself to by/build anything without at least 10G between each item.

 

[Evan!]

Cool. I 'll probably still add one in the future. I would also use it for recirculating through a CFC. But I've also found one pass with gravity chilled my wort down to pitching temps as well. Does the pump just allow you to do it faster?
I have many more things before worrying about a pump. Such as ingredients.Trying to break my Hobby Equipment Whoring this year. Not going to allow myself to by/build anything without at least 10G between each item.

The pump just allows you to not have to arrange things too much according to where the liquid is going to end up. For instance, I can have my carboy above the level of the kettle and still transfer wort there. You don't necessarily want to go faster, because that means less contact time with cold water in the CFC, and thus, less chilling...unless you recirc it, which is what I do, but with an IC and not a CFC. The pump pulls from the bottom of the kettle, through the tubing, and then back into the kettle via a copper recirculation arm which is attached to the IC with zipties...and it gets shot back into the kettle at an angle, which gets a whirlpool going in the kettle and increases the efficiency of the IC. None of this would be possible without the pump. Now...the final transfer after chilling to the carboy, that is MUCH quicker than it used to be.

 

[fifelee]

Oh and my dip tubes often seem to have air in them (locked in from when it was empty and I filled from the top) so I'm planning on doing a cheap bottom mount drain, look for a how-to thread soon... if it works.

This seems to be my problem as well. I also wonder if steam created when boiling doesn't fill the dip tube even if it was primed. I wish I would have welded an elbow to the bottom of my converted keg instead of a coupler on the side. I'll watch your progress. If it works, it may be time to start looking for some more decommissioned kegs.

 

[dmaxweb]

The needle valve. When it's closed, no liquid can make it out the bleeder tube.

Isn't this only a bleeder valve?

Is there a needle valve in the pump set-up picture that I am not seeing?

 

[missing link]

The PDF instruction sheet on the March web site recommends 3/4 inch input hose and 1/2 inch output hoses. I am thinking you can mimic this by just closing the output valve slightly but I'd like to try a 3/4 in ball valve and hose between the MLT and pump.

Linc

 

[Evan!]

Isn't this only a bleeder valve?

Is there a needle valve in the pump set-up picture that I am not seeing?

The picture of the pump posted above did not have one of those cable-pull bleeder valves. All it had was the needle valve and tubing beyond.

 

[SpanishCastleAle]

The PDF instruction sheet on the March web site recommends 3/4 inch input hose and 1/2 inch output hoses. I am thinking you can mimic this by just closing the output valve slightly but I'd like to try a 3/4 in ball valve and hose between the MLT and pump.

That seems like it would be harder to prime than the reverse of that. Bigger lines on the suction side just make it that much harder to prime and any restriction on the pressure side does the same.

If you had to start a siphon which would be easier to start...1/4" tubing or 1" tubing? Same with priming a pump imo.

 

[FSR402]

That seems like it would be harder to prime than the reverse of that. Bigger lines on the suction side just make it that much harder to prime and any restriction on the pressure side does the same.

If you had to start a siphon which would be easier to start...1/4" tubing or 1" tubing? Same with priming a pump imo.

That's what it's saying, A larger hose going to make more pressure (weight) to push the air out.

 

[SpanishCastleAle]

That's what it's saying, A larger hose going to make more pressure (weight) to push the air out.

It said a larger hose in the suction/inlet side. Take an extreme example; what would be easier to prime: a 1/4" ID tube or a 1 mile ID tube? See how hard it would be to get a good prime on that 1 mile ID tube? But just a little suction on the 1/4" tube would prime it easily.

IMO, it's not really about getting the air out per se...but more about getting pure liquid to the suction side. Once you get pure liquid at the suction side you're golden...the pump will take care of getting the air out (as long as you give it a path).

 

[Bobby_M]

Nope... a one mile diameter inlet has a lot more weight. The pump doesn't provide suction at all. You need the weight of the liquid in the inlet tubing to push the air out of the pump head.

To the point of the siphon tube filling with air/steam and then flushing into the pump's inlet line.... I just ordered a brass schrader valve stem from Mcmaster and I'm going to drill into the elbow of my brass QD and solder that sucker in. A little tap on the valve should let the air escape from the line.

 

[Boerderij_Kabouter]

To the point of the siphon tube filling with air/steam and then flushing into the pump's inlet line.... I just ordered a brass schrader valve stem from Mcmaster and I'm going to drill into the elbow of my brass QD and solder that sucker in. A little tap on the valve should let the air escape from the line.

Brilliant! And to go one up from there, why not use a Presto valve, cut off the base, tap and thread a hole into the output somewhere, and thread the presto into the tapped hole. Also, presto valves can be locked down.

Awesome idea!!:rockin:

 

[FSR402]

It said a larger hose in the suction/inlet side. Take an extreme example; what would be easier to prime: a 1/4" ID tube or a 1 mile ID tube? See how hard it would be to get a good prime on that 1 mile ID tube? But just a little suction on the 1/4" tube would prime it easily.

IMO, it's not really about getting the air out per se...but more about getting pure liquid to the suction side. Once you get pure liquid at the suction side you're golden...the pump will take care of getting the air out (as long as you give it a path).

The only way you would be sucking it would be if the pump was higher then the kettle.
I understand what you're saying but what they are saying is that a higher volume of fluid going into the pump works best.
So with a larger hose in the inlet there will be water/wort "waiting" to be pumped thru.

 

[SpanishCastleAle]

I see what you're saying FSR402. But if the kettle is above the pump then the pump should already be primed. Since people were having problems priming I assumed that wasn't the case.

Just because it's primed doesn't mean it will move liquid though. There could be too much head pressure or the pump could be cavitating, etc...but that's different than 'not primed' imo.

The pump doesn't provide suction at all.

Of course it does. There is suction on one side and pressure on the other. Since it's centrifugal it's not a lot (esp when not primed)...but it wouldn't work if it didn't have a differential pressure across the inlet/outlet. How does the liquid 'know' to move? The pressure gradient.

 

[conpewter]

All my pots are above the pump but I still have to get it to prime, then again mine is not a march 809, it is supposed to be used in conjunction with water pressure (circulator pump)

 

[flyangler18]

I see what you're saying FSR402. But if the kettle is above the pump then the pump should already be primed. Since people were having problems priming I assumed that wasn't the case.

March pumps aren't self-priming.

 

[cdburg]

I think everyone has a plan figured out, but just in case someone else is looking for another idea, I recently added this to my pumps. Opening the side valve until liquid flows through then closing it and opening the top valve it gets everything flowing almost every time.

 

[FSR402]

I think everyone has a plan figured out, but just in case someone else is looking for another idea, I recently added this to my pumps. Opening the side valve until liquid flows through then closing it and opening the top valve it gets everything flowing almost every time.

why wouldn't opening the the top valve do the same thing?

 

[SpanishCastleAle]

March pumps aren't self-priming.

I know...I've been using them at work for years. Often mine won't pump liquid either...but it's not because they aren't primed. 'Not primed' isn't the same thing as 'too much head pressure' or 'impeller cavitating'...both of which will prevent the pump from moving liquid.

 

[missing link]

I think a lot of the trouble with getting the pumps to move liquid is due to the fact the inlet and outlet are both above the pump. As soon as you get the outlet below the inlet you get instant flow. That is why the valve in the picture above is so effective. It lowers your outlet by a few feet creating less resistance to pumping.

Linc

 

[cdburg]

why wouldn't opening the the top valve do the same thing?

When the lines are hooked up to the pump, in my experience, opening the top valve does not do the same thing. I can't explain why, scientifically. Before I switched to this set up, getting the pump to push liquid through my heat exchanger was really tough. Between the air in the lines, exchanger and pump head, it was very tough to not end up with a captivated pump. The new set up makes it simple to get everything flowing.

Just opening the top valve toward the tubing does not allow it to pump. Having the second valve open to let the air out before it hits the tubing makes a difference. I can then switch to the top valve to send the pumped liquid through the tubing.

I got the idea here:
Morebeer's Brew Chat • View topic - March pump "head' question

The set up is described in some detail there. Hopefully it helps someone.

 

[Bobby_M]

Here's what I came up with to vent the air bubble out of the inlet tubing. This is the QD that goes on the vessel I'm pumping from.

For now I plan to leave the valve assembly out of the stem and just loosen the cap to vent. I'll write up more after I test it out.

 

[FSR402]

Here's what I came up with to vent the air bubble out of the inlet tubing. This is the QD that goes on the vessel I'm pumping from.

For now I plan to leave the valve assembly out of the stem and just loosen the cap to vent. I'll write up more after I test it out.

are the seals and cap rated for the temps they will be put thru?

 

[slimer]

Looks like a schrader valve, so the cap is there just to provide some protection. It works like this:

 

[Bobby_M]

I know how a schrader valve works. I unscrewed the valve assembly and decided to leave it out for now because that air pocket isn't going to be under much pressure. I'm pretty sure the cap can handle the temps but if not, I have a metal one. During a brew session, I'll go ahead thread in the valve to see if it works but poking something in to push on the pin would get really annoying.

I actually meant to have the tube sticking up but totally beefed it when I drilled the hole. Having the elbow part disassembled from the QD screwed up my perspective and I was in a big rush.

 

[slimer]

I know how a schrader valve works. I unscrewed the valve assembly and decided to leave it out for now because that air pocket isn't going to be under much pressure. I'm pretty sure the cap can handle the temps but if not, I have a metal one. During a brew session, I'll go ahead thread in the valve to see if it works but poking something in to push on the pin would get really annoying.

I actually meant to have the tube sticking up but totally beefed it when I drilled the hole. Having the elbow part disassembled from the QD screwed up my perspective and I was in a big rush.

I was replying to FSR402.

It looked like you put a schrader valve on your QD. Sorry for the misunderstanding.

But if you're thinking about adding one, the ones on bikes are very easily pushed in. You can do it by hand and there's a second set of threads to tighten it so there's no leaks.

 

[Bobby_M]

No problem. I picked up this schader on mcmaster. It actually had 1/8" NPT male threads on it but I didn't have a tap. An NPT tap and die set is really something I'd love to get my hands on but they're really pricey.

 

[fifelee]

Liked Bobby's idea so much thought I would give it a try.

Have you tested it yet bobby?

 

[Bobby_M]

Niiiiice. No, no brewing in my near future. Kitchen renovations ...

 

[nathan]

if you hook up too much stuff right away, the pump will have a hell of a time priming, so I start with just one section of hose at the pump outflow (where I have a valve as well). Turn on pump, when I prime enough to fill the in and out hoses, I turn off the valve and go put the hose on where I want it (you can kink the silicon to drip less while moving).

You may find that if you have dip tubes in your vessels that air gets trapped in them (all three of mine are like this). I find that the very first time I need to use those valves, those tubes are full of air and stuff doesn't want to prime and start. So I hook up hose from ball valve to pump, and hose from pump to nothing, and I open the ball valve and just give a good suck on it, which will pull the air into the first tube. then angle the tubing up so it's trapped in a high point, and work it down to the pump. Once it rises up through the pump you are usually golden.

One hint for avoiding this issue is to fill your vessles through the ball valves, at least for a second or two, so the tube is full of fluid, not air.