Aerator ballast pump flow problems

[jbanczak]

Hey guys -

I setup a ballast system in my 230VRS this winter. Basic setup with 2 rear bags for now. I'll be posting a full write-up on my experience once I get it working...

I am using the Rule 1100 pumps - four total - one fill and one empty for each tank. The empty works fine. I put one thru-hull on each side, ran the vent and drain together in a T using swing (not spring) check-valves. It empties perfectly.

Fill is another issue. I teed off the engine coolant intake line. Engine still running just below 160 as always, flow of water there not an issue. Put the same swing check valves at the opening of the bag - so there is no chance of water build up to pressure the pump. I took one off to see if that was the issue, and it made no difference.

The pumps are located below the engine intake line, sitting on hull of boat. They are below waterline, and I verified that water flows freely to them. Here is my issue:

When I start the pump, the flow is very, very slow. It feels as if the pump is starved for water, yet I've verified that it should not be. After about 5 minutes or so the pump picks up speed and then appears to work just fine, filling the 750lb bag in about another 6-7 minutes.

Any idea on why it would take this long to pick up speed? Could any of these be the issue?

* No swing check-valve on the intake hose between the T for the pumps and the engine intake - thus the pumps are actually sucking backwards against the engine intake and getting some air in there? Doesn't really make sense though since if that were the case, it would never pick up speed.

* The pumps are about 2.5 ft of tubing away from the actual thru-hull - is this just too much hose in advance of the pump even though they are below waterline, thus taking some time to truly get primed?

Any other ideas? Feel like there must be an "ah-ha" moment coming - just can't seem to find it.

[Jesus_Freak]

...

* The pumps are about 2.5 ft of tubing away from the actual thru-hull - is this just too much hose in advance of the pump even though they are below waterline, thus taking some time to truly get primed?...


Dont know much about your system, but you could easily ballpark how much time this would take: Divide the hose volume by some estimate for the pump volumetric throughput. Since it eventually catches up, it is not likely a pump NPSH problem (too much hose for the pump).

[swatguy]

At first guess I would tink that the fact your hose is 2.5 ft away from the actual intake is a proble. They should be right in line and an actual T in the line. You should have not added any hose except from the pump to the bag. The should be t'd right intpo the line. Here is the problem if I read your wording right......Pics would help me be more specific but if your pumps re on the hul of your boat and not actually in direct line with the intake the water has to go up and then back down to the pump. I think what happens is the suction from the water pump is preventig that water from actually "falling back down" to the pumps. Again hard to determinw w/o pics.

Secondly are you filling while standing still or while underway?

[jbanczak]

Thanks for your responses guys - once the pump catches on - it fills really fast. I disconnected the hose from the bag to watch it. It starts with a trickle for a few minutes, gathers pressure, then eventually is like a hose.

I think the water not falling down issue could be the issue, but seems like if they are below waterline, it shoudln't. I teed them there because of the room in the compartment, and in theory as long as they are wet they should work. They do eventually work - so I kind of ruled that out.

I have tried filling when running and standing still. Both seem to be same.

I had another thought - I have a stand-alone tsunami for filling random bags - I have noticed that from the pump to the bag when filling cannot have any water in it - it needs to be clear between the pump and bag - for it to work properly. That could be happening with the rule - the line AFTER the pump is under waterline.... so in theory it could have water in AFTER the pump - creating pressure that the pump cannot overcome very easily. I think the way these things are supposed to work is that the intake of the pump should be below waterline, but the output needs to be above it - could that be it?

[jbanczak]

Actually - I think I might have figured out the problem. I have the pump mounted horizontally, with the output line horizontal as well. I just read that the rule pump must be vertically mounted, OR the output line must be pointed vertically. Unless this is done, air bubbles form inside the pump and it cannot fully prime.

I will try this out in the next few days unless someone has other thoughts?

[TallRedRider]

Actually - I think I might have figured out the problem. I have the pump mounted horizontally, with the output line horizontal as well. I just read that the rule pump must be vertically mounted, OR the output line must be pointed vertically. Unless this is done, air bubbles form inside the pump and it cannot fully prime.

I will try this out in the next few days unless someone has other thoughts?

DING DING DING!!!!!!!!!

We have an answer.

I have spent a lot of time reading about and installing a ballast system in another brand's boat. The manufacturer even had some major problems with this exact issue. I know it sounds like it makes sense to have the water trickle DOWN to your pump, but with your setup, it simply will trap an air bubble in there and you get your experience. I bet if you actually put the pump a little HIGHER than the T on the intake, it will prime better, as long as it is still below the water line. That allows the air to escape.

You have an air pocket trapped between the intake and the T.

Reach in there and lift the pump up and you will get a good flow. I would also shorten that hose if possible.

[jbanczak]

Going to try it this weekend - thanks for all the input. Will report back then hopefully post the final project/pics/parts list assuming I have a working setup!

[jbanczak]

Tried changing the orientation. That did not help - although ultimately I think it is the right way to lace them.. I think flow is actually the issue. Going to run a dedicated manifold lower to the hull/closer to the thru-hull. Will keep everyone posted.

[jbanczak]

Finally - success. Ultimately this was a priming issue. The inbound line to the pumps was at one point partially higher than waterline. So the pumps would get a little flow, but not enough. I re-routed that by creating an elbow out of hose and bronze pipe - it lowered the highest point by a good six inches.

The pumps (Rule 1100's) now have no hesitation at all. Running them while running the engine results in no engine temp increase either - engine still runs between 150 and 170 depending on rpm's.

I have 750lb bags in both lockers now setup automatically, and they fill or drain in roughly 5 minutes. Very fast. 300lb in ski locker, 400lb in box, then depending on people in boat, throw a 400lb across back seat or not.

I'm going to take some pics post a better description of the system online once I get a chance. It is based on the Rich_G description and setup. I more or less copied that system, except for the thru-hull.

[leetudor]

DING DING DING!!!!!!!!!

We have an answer.

I have spent a lot of time reading about and installing a ballast system in another brand's boat. The manufacturer even had some major problems with this exact issue. I know it sounds like it makes sense to have the water trickle DOWN to your pump, but with your setup, it simply will trap an air bubble in there and you get your experience. I bet if you actually put the pump a little HIGHER than the T on the intake, it will prime better, as long as it is still below the water line. That allows the air to escape.

You have an air pocket trapped between the intake and the T.

Reach in there and lift the pump up and you will get a good flow. I would also shorten that hose if possible.

Mr Know it all guy! ;):D