Liquid Ring Pump Setup

[Amber Gold]

Having issues with my Atlantic Fluidics A10 liquid ring vac. pump. It's an issue that's gotten worse over the past year or two, and now I'm using excessive amounts of cooling water (I think, at least compared to year's past) to keep the pump head from cavitating/losing its prime...sounds like marbles bouncing around in the pump. Also, only getting about 20" of vacuum, but that could be due to their being so much incoming water that there isn't much room to move air??

I have the pump sitting on top of its water stock tank and it draws water out of it. I've had it set up like this before in another location and it was fine. It's been recommended to me to set the pump centerline to the storage tank water elevation, but that's going to mean a lot of work to reconfigure the pump shed and plumbing. I was also wondering about putting the pump at floor level and hooking the pump up to the tank drain, so the pump head is always flooded. Not sure what the best setup is.

Looking for ideas on how to set up liquid ring pumps to see what others are doing, or if maybe I'm doing something wrong.

Thanks.

[Brian Ryther]

Put a valve in the water feed line. Start with the valve fully open then close it down until the pump evens out and the vac levels begin to rise.

[GeneralStark]

I have always gravity fed LR pumps from a tank and use a valve in the feed line to control the flow. With my current pump flow rate doesn't seem critical but that is with only about 3' of head and a 1/2" feed line. With a previous pump with higher head, controlling the flow rate was more critical. My current pump only cavitates when it does not get enough air, but I have seen too much water do it as well in the previous setup.

If you are sure you have no leaks in the woods, and nothing else has changed since last season, try a valve as Brian says to control the flow, and then perhaps try gravity feeding it if that does not work.

[OldManMaple]

When I bought my A20 I was told to have the water level in the tub at the center line. It came with a flow meter and a gate valve to fine tune water flow. I find that like the General said water flow directly affects vac level. I deadhead the pump and adjust water flow until I get max vac. Too much water and vac drops off. There must be a reason for having the water at the centerline. I think it has to do with the setting up ideal conditions to make a the seal but thats just a guess
I would start with what Brain said.
And putting the pump low might give you problem at start up if the pump is full of water.

[wiam]

My pump is below the tank and it starts fine full of water. It is a 3 hp Atlantic.

[Amber Gold]

Thanks for the input.

Attached is a pic of the current setup. The blue tubing is from a groundwater well for a cold water source. The ball valve regulates how much water is pulled from the tank. The gate valve regulates how much water is coming into the system. Right now, it's almost wide open. Does anything look wrong in this setup? To start, I'm thinking about putting a check valve between the vac. line and gate valve...idea is it'll keep water from getting pushed back into the tank if there's a slug of air. Also going to pull the pump casing off and look at the internals to see if all looks good.

So I don't need to mess with the plumbing/tank inside the pump shed, I have a second stock tank and can set up outside. I can set the tank high enough, so the tank overflow is set to the centerline of the tank and plumb the pump to the tank drain. I can also raise it higher and get the tank overflow set higher than the pump, so the pump head is completely submerged. If I do either of these setups, should the water feed line be plumbed into pump's service water port? This would keep the vac line just a vac line straight to the pump w/ no water in it. In either situation, what size should the feed line be? For flexibility, would 5/16" maple tubing be big enough, or do I need 3/8 or 1/2" PVC tubing?

13140

[GeneralStark]

In seeing the setup, I would personally suggest using the service water port on the pump instead of the vac. line for supplying and regulating the water supply to the pump. I don't know these pumps but I would think that having a dedicated vac. line and a dedicated water supply would limit the potential issues.

How about just trying that and see if the pump will pull the water up from the existing tank. I would use 1/2" and put a valve in the line to control flow.

[Amber Gold]

Thanks General, I'll get hooking up a water supply to the water service port. Easy enough to do. I wasn't sure if it created vacuum on that side of the pump head and would actually suck water out of the tank.

[BAP]

Your last fitting going into the pump. Is it reducing the input size into the pump? If it is, you might want to change it so you are using the full size available to the pump to get maximum vacuum.

[Risingsweetnesssugarshack]

Bap, the port entering is only 1".

[OldManMaple]

Here's a picture of my set up. One has the flow meter one doesn't. The small line comes from a brook

[Amber Gold]

Thanks for the pics. The setup is similar to mine, except you have the pump at the water level.

I called Goodrich's yesterday to see if they had a port cylinder in stock. I asked them about pump setup. They typically put the pump at the water level, but have heard of others setting the pump above, and below the water storage. He said the service water feed is for if the feed water's under pressure...maybe the pump will not draw the water in...not sure. But if the pump is set at floor level, the height of the water above the pump will push it into the pump through the feed port.

When I got to the woods this morning, the vac. level was at 23.5" and held steady all day. Not sure how it gained 2"+ since even deadheaded before, it wouldn't go any higher. I decided to leave it be since the sap was already running, and I had another mainline to tap in. Finished the day at 23" and knowing I have leaks in the woods. Hoping to have time tomorrow to tinker with the pump

[500592]

When I had problems with mine I called them directly at the factory and spoke with a tech and he gave me specs for the internal part sizes. Mine was an eBay purchase and they guy told me by the name tag that it was a very very old pump. Turned out to be the internals were worn out and I was able to purchase new ones very easily from them and had it pulling 27 inches after that. I'm not sure if you have ever taken one apart but if you have you'll see that there really isn't any parts that touch because it's the water that makes the seal. I think that mine was worn out due to dirty water so I try to make sure I run fairly clean water through mine

[Amber Gold]

That's what I've heard from a fellow producer. He replaced the port cylinder and all was good with his pump. Did you replace anything other than the port cylinder? What'd it cost you? I have taken the cover off the A20 I have, and they are extremely simple.

I moved the stock tank outside the pump shed and raised it so the water's almost centerline with the pump. After filling it, I realized I'm a couple inches short, so need to go a bit higher. This was late yesterday, so no verdict yet if this fixed the problem.

[500592]

I had to replace the front cover the rotor the deal and the port cylinder I believe I think total it was around a grand but I had only paid 200 for the pump and after that it is a brand new pump basically.

[Amber Gold]

Thanks 500592. Not cheap, but if it gets you back to pulling 27" it's worth it. To get the rotor off, do you remove the center bolt and pull it off? Wasn't sure if you needed a puller to get it off the shaft. I wonder what role the cover plays in creating the vacuum.