Noisy check valve... any ideas?

So I've built this glycol manifold pictured below (under the VT sign). It works fine, but I'm getting this weird noise out of it I don't understand.

When I first start up the chiller everything is fine. Glycol runs into through the side with the solenoids at the bottom, if the solenoids aren't open it flows up to the top and the top contains a 5psi cracking pressure check valve. That pressure the pump from the chiller can output (checked with a pressure gauge). Once that is cracked open it just goes to the return at the bottom of the left side. If a solenoid opens, there is less than 5psi of pressure at the check valve so it does not open any longer and glycol just flows out the solenoid and in one of the outlets.

But - after a random period of time the check valve starts making a crazy noise. Best I can describe it is a weird buzzing humming - and it's very loud not quiet - louder than my damn glycol chiller! But if I disconnect my return line for a second and then stick it back on, it goes away - for a bit.

The best I can come up with is barely breaking cracking pressure on the check valve but I completely don't understand why it would be ok for a while then.

Any ideas? Is there something wrong with the design of my manifold that I'm missing? Thanks for any ideas!

Hmmmm, temperature change changes the spring rate in the check valve?
I don't see right off where it's located, but if you could change the orientation of it, (vertical to horizontal , etc...), that may help.........But it's doubtful, if it is temp change induced.
If it's plumbed in a "hard line", you may try to cover the line with some more pipe wrap foam.
I'm guessing if it's metal to metal on both ends, the noise will just "telegraph" when it's oscillating, ( check valve).

That's interesting... I mean the glycol I'm sending through is only running about 60F so I wouldn't think it would be that significant but who knows.

In that pick, the top of the upside-down U is the check valve and it's currently wrapped in foam which is why you can't see it. It is a brass check valve. It's all hard line - all pretty much stainless fittings with exception of the check valve.

The orientation idea is interesting. Can't say I can logically understand it but anything is worth a shot.

Only other thing I can even think to try is a lower cracking pressure but lower is 1psi. So it's a gamble if that'll work or not.

I was kinda' unsure about the "random period", as if it was from room temp to design temp.
Just curious , what is the check valve used for, maintaining pump prime?

Ya I'm unsure about the random period too lol.

So the design is such that - when both solenoids are closed (these are the solenoids to the glycol in for the fermenters) - there is enough pressure to open the check valve and let glycol pass through to the return at the glycol unit. The reason for this is the pump uses glycol to keep cool and lubricated. If you don't return glycol the pump will burn out.

When a solenoid opens, there isn't enough pressure to open the check valve and all glycol is pushed through the solenoid(s) and then it is returned on the left side past the check valve.

Make sense? It was the best way I could think to do it.

jcaudill said:

Ya I'm unsure about the random period too lol.

So the design is such that - when both solenoids are closed (these are the solenoids to the glycol in for the fermenters) - there is enough pressure to open the check valve and let glycol pass through to the return at the glycol unit. The reason for this is the pump uses glycol to keep cool and lubricated. If you don't return glycol the pump will burn out.

When a solenoid opens, there isn't enough pressure to open the check valve and all glycol is pushed through the solenoid(s) and then it is returned on the left side past the check valve.

Make sense? It was the best way I could think to do it.

Click to expand...

Can you watch the return flow before and during the buzzing?
Check the data sheet to find the flow rate at 5 PSI.
I have a feeling the pump can not make it.
Try setting the valve pressure to 3 PSI if adjustable.

Look at my bypass flow video, diffrent design.


The noice is a combination off condenser, two CIP pumps running.
Cheers,
ClaudiusB

Hey there Cladius... ok I will take a look at that and I think you are probably right. Unfortunately it is not adjustable and I didn't have much luck finding one that was with 3/8" NPT ends. But I did order a 1PSI version thinking maybe that will help.

I took a look at the video but I couldn't quite figure it out - can you explain?

jcaudill said:

Hey there Cladius... ok I will take a look at that and I think you are probably right. Unfortunately it is not adjustable and I didn't have much luck finding one that was with 3/8" NPT ends. But I did order a 1PSI version thinking maybe that will help.

I took a look at the video but I couldn't quite figure it out - can you explain?

Click to expand...

My video shows the glycol chiller bypass flow when all solenoids are closed.

Cheers,
ClaudiusB

If the solenoids are closed, ( temperature reached, yes?), then why not turn off the pump?
Your glycol reservoir will then stabilize it's temp, and shut off it's chiller, yes?
When your product needs chillin', could you not just signal the pump to start, and solenoids to open?
Lemme' know what I'm missing, please Sir, 'cause it sounds like to this Layman there are some unneeded sequences there if only to keep the pump cool.

Actually to be completely honest that option never crossed my mind!

Reason being the pump is currently being powered by an outlet provided on the chiller so it didn't cross my mind. I'll have to find out if that is stepped down or 110 and then I'd have to add another solenoid to the mix which I was hoping to avoid.

Stealthcruiser said:

If the solenoids are closed, ( temperature reached, yes?), then why not turn off the pump?

Click to expand...

Would not work with multiple fermenters, like in my case.
Most pumps are designed for continues run and not for many start and stops.
Data sheet list start/ stops per hour.

Your glycol reservoir will then stabilize it's temp, and shut off it's chiller, yes?
When your product needs chillin', could you not just signal the pump to start, and solenoids to open?

Click to expand...

With a single fermenter possible.

Cheers,
ClaudiusB

I am running multiple fermenters too so ok back to the drawing board.

Cladius sorry man still not grasping the bypass but my hunch is you do it via solenoid?

Look out!
Here I go thinkin' again!

Why, another solenoid, if when your temp is reached, all chiller functions shut down?

That's an easier one! I only have a 2.5 gallon bath - temp would go up very rapidly. My fermenters take a good amount of time to rise a degree though because they are well insulated.

jcaudill said:

I am running multiple fermenters too so ok back to the drawing board.

Cladius sorry man still not grasping the bypass but my hunch is you do it via solenoid?

Click to expand...

Your method is used throughout the brewing industry with more powerful pumps.
Find the right matchup for your pump.

My method is non conventional and I am a gadget guy.
The system monitors all fermentation controllers.
If no fermenter cooling is on for a fixed time a bypass valve opens the return pad to the 30 gallon tank.
The bypass valve is a motorized spring return, made by ERIE.
I had that valve in stock.

Gotcha! If I can't seem to get the check valve right than I'll add another solenoid to the mix as a bypass instead. I'm hoping maybe the 1PSI version will pull this off - all depends really if when a solenoid is open it is able to pull away all the flow before it hits the check valve successfully. If the whole path of least resistance things plays out it should

So far the new 1 PSI valve seems to be doing a much better job! The only thing I'm afraid of is that the return flow may be getting bottlenecked at the manifold if the check valve isn't closing when the solenoid opens. I have to double-check this closely - if so I have to figure out some kind of solution for that.

Ok so - the check valve is working. However, I've noticed something that I can't rationalize if it's a big deal or not.

One thing I was worried about with only a 1psi cracking pressure is that even with 1 solenoid open, there would still be enough pressure from the glycol chiller pump to pass the solenoid, keep the valve open and let cool glycol pass. I have been suspect this has been happening because one thing I've been noticing is that the return side of my immersion chiller has a relatively weak flow. This either means I'm not able to push glycol through fast enough, or, the return side isn't able to dump it fast enough back into the manifold because of the flow the is bypassing the check valve.

The whole setup has been working relatively well - although I did witness with the solenoid open when I tried to drop my bath temp down to 35 (fermenter is sitting at 60) the chiller was struggling. Once the solenoid closed it managed to get down just fine. This is probably just because I have such a small bath (2.25 gallons).

Any thoughts? I'm just trying to decide if I need to get a stronger check valve or not. One thing I know I need to do is move my manifold lower so gravity can carry the glycol down.

Any advice much appreciated!

jcaudill said:

Ok so - the check valve is working. However, I've noticed something that I can't rationalize if it's a big deal or not.

One thing I was worried about with only a 1psi cracking pressure is that even with 1 solenoid open, there would still be enough pressure from the glycol chiller pump to pass the solenoid, keep the valve open and let cool glycol pass. I have been suspect this has been happening because one thing I've been noticing is that the return side of my immersion chiller has a relatively weak flow.

Click to expand...

I think the 1 psi check valve is a problem.
Look at the data sheet to find the ON/OFF points.

The whole setup has been working relatively well - although I did witness with the solenoid open when I tried to drop my bath temp down to 35 (fermenter is sitting at 60) the chiller was struggling. Once the solenoid closed it managed to get down just fine. This is probably just because I have such a small bath (2.25 gallons).

Click to expand...

I am lucky my tank holds 30 gallons without any cooling problems.

I'm just trying to decide if I need to get a stronger check valve or not.

Click to expand...

Most likely.

I have an idea in case the higher pressure check valve won't work.
What temp controllers are you using?

Cheers,
ClaudiusB

I definitely confirmed the check valve on the cold side is a problem - it's allow too much flow past the solenoid.

Once this glycol pack can't keep up I'll probably do something like you did so I have a bigger bath - to this point glycol pack to fermenter has been one-to-one so it hasn't been a problem but now I can see the effect of how the fermenter heats the bath super quick.

Right now I'm using a spare A419 to test - but I am going to be building a custom Arduino solution to control two fermenters, I'd love to hear your idea!

Prost!