Check Valves ?????

I am installing a ballast system where I have reversible pumps to fill and empty thru the hull, and the overflow is thru the side of the hull. the check valve I am using doesnt seem to flow very good, and causes the sac to fill very tight. It is the PLastic one 3/4" from Home depot.
Which one should I be using for better flow?

I don't use check valves on my over flows, because I had the same problem. It works fine with out them.

(Message edited by analdine on October 16, 2008)

Sounds like they are the plunger type, I have the same problem with them.

You will need to swap them out for a flapper type check valve. you can find them online

www.mcmastercarr.com
www.plumbingsupply.com
www.flexpvc.com

One thing we did in the early days of ballast systems - with these check valves - is the following:

If it is the plunger type we worked with before - there should be a screw holding the plunger in. The screw should hold the plunger - then a spring under the plunger. We used to take the spring out for better performance.

See if that helps.

Analdine, Do your sacs drain all the water and air out?

mbouchard, I thought about cutting the spring to make it lighter. I might try what you said.

You need to use a swing check valve.

Note that if you get a brass swing check valve try and mount it at an angle where the valve is "dangling open". If it is mounted so the valve is closed all the time the valve will tend to get "sticky".

Dont use brass, although they'll work. Pick up a plastic swing check at your local plumbing supply house.

I installed a a bow sac using a reversible pump. I tried going without a check valve and it never emptied well. Always left quite a bit of water in there. I put check valves in the over flows now. With the spring check valve it sucks the bag completely dry.

So with reversible pumps like the Jabsco unit, I dont need any check valves on the fill/drain lines, just on the vent line?

correct

Actually, you should use the Jabsco pump to fill only and then use an aerator pump on your vent line for draining. Eliminates check valves and keeps the impeller from having to reverse direction al the time (reduces chances of getting stuck).

The bags will also drain a lot faster.

Centurion does it this way.

Just my $0.02

Tuneman why wouldn't he just use two aerator pump, one to fill and one to empty if he's not going to reverse his Jabsco pump. It sure would save him alot of money.

Tuneman,

I agree with the thinking behind that 100%, so I ask this question to the group: What would be the advantage of using the $170+ reversible pumps then, when a $35 aerator will move just as much water??? Vapor-lock, the aerator's most common problem, can be prevented with proper manifold/pump orientation.

I love the simplicity of the reversibles, but cant get past the cost and high number of impeller failure.

My $.02 - you need to use a CV on the vent line so the pump will draw a vacuum on the sac, 2 reasons why this is needed = if the sac is allowed to draw air while draining it will allow the pump to draw air when the water level gets low and you will have an incomplete drain. 2nd, once the pump draws air, it is now running dry leading to impeller wear. If I'm not mistaken, the Ballast Puppies have a run dry protection based on load to shut the pump off when running dry, but, I believe this same protection circuit will trip when the sac empties and the pump begins to draw a vacuum (here's where the CV comes in) as the load with go up, but the pump is not dry yet. If you're using a pump without run-dry protection, it will run till you either turn off, blows fuse, impeller grenades, battery's dead.

Any other thoughts on this???

I like the simplicity of a reversible pump system, thats why I am going that route. the idea of having 2 pumps instead of 8 just seems more palatable to me. Time will tell if I get fed up with impeller issues or not. I agree that check valves on the vent lines are prudent to a full drain.

Just keep in mind that impeller pumps are veeery slow, compared to an aerator pump. A jabsco ballast puppy will do 540 GPH, at best, and cost about $170. An Attwood aerator pump will do 800 GPH and cost about $35.

Also, an impeller pump makes noise. If you have a lot of ballast to fill, you're going to hear a whirr sound for some time. Aerator pumps are virtually silent.

One more thing. Only the Jabsco Ballast Puppy is ignition protected. So be careful which impeller pump you buy. Aerator pumps are completely sealed.

(Message edited by tuneman on October 23, 2008)

Bought both Jabsco pumps new off ebay for $140 (thats for both). I'll see how they work next spring after I get the install done over the winter. Still lots of planning to do before I start drilling holes.

(Message edited by drknute3 on October 23, 2008)