Ballast Pump Flow Comparison

[chpthril]

Why to go Chpthril! You saved me some time and also assured me that the T-800's are an ok choice.

What isn't solved for me is am I building a manifold or individual thru-hulls? I keep going back and forth but after all the threads I have read it doesn't seem right to mount the T-800's in the vertical position.

My electrical is 90% done just need to cut holes in the dash and mount/connect the switches. So I will need to decide pretty quick on my manifold vs. individual thru-hulls. Maybe I will flip a coin!

From a feeding the pumps standpoint, a 1-1/4" common manifold with support 3-4 pumps with know issue.

Individual 3/4" thru-hulls will work just fine. You can even add an elbow to the ball-valve so the pump lays on it's side.

Putting the pickup in the transom works fine, the only downside IMO, is that you cant fill on the fly.

I've done the common manifold and the single shrooms, and it really comes down to which setup will fit best in the bilge so you can orient the pumps in order to avoid vapor-lock.

[Timmy!]

@WABoating - The data above supports the 1" > 3/4" hose theory. I think what you need to do next is weigh the cost of making everything 1" hose vs 3/4" hose. Tsunami 800's are cheaper, 3/4" hose is cheaper, 3/4" thru hulls are cheaper, smaller hose clamps are cheaper, etc.

[IDBoating]

@WABoating - The data above supports the 1" > 3/4" hose theory. I think what you need to do next is weigh the cost of making everything 1" hose vs 3/4" hose. Tsunami 800's are cheaper, 3/4" hose is cheaper, 3/4" thru hulls are cheaper, smaller hose clamps are cheaper, etc.

What I'm trying to do is overcome the inherent limitation imposed by those small 3/4 inch fittings on the sacs themselves. Many of the sacs have multiple top and bottom fittings. I agree that a one inch system (pumps, hoses, fittings, etc.) is somewhat more expensive than a 3/4 inch system, but it's way less expensive than dual pumps.

Maybe we can get a "poor man's speed increase" with a hybrid of the two. Spend a little more on a one inch system, then right at the sacs split it into two hoses each connecting to a separate 3/4 fitting. Now you'd have a full one inch system, with no artificial restrictions to limit the pump's throughput, and instead of it running into a 3/4 restriction at the sac it would see two 3/4 fittings.

Let's presume some easy numbers. A one inch aperture (hose, fittings) has 0.79 square inches of cross-sectional area. A single 3/4 aperture (fat sac opening) has 0.44 square inches. In other words, the sac's opening is about half that of the system driving it. That is serious restriction. But if the one inch system was driving TWO fat sac fittings, then the 0.79 aperture would see a combined cross-section of 0.88.

And you can have this reduction for the cost of a little bit more hose and one extra Y fitting. No wires, no pumps, no valves. You'd want to be sure to use a Y fitting, and not a T, because Y's have significantly less insertion loss. Something like this:



If I had the equipment I'd run the test myself, but I don't. (hint hint hint)

[IDBoating]

But for those of you who insist on manifolds...

...here's a $13 solution:



Check these guys out - I had no idea you could get PVC fittings like this.

http://flexpvc.com/cart/agora.cgi?product=PVC-Manifolds

[chpthril]

[QUOTE]

I originally thought to go with a single huge inlet (1.5 or 2.0 inch) into a manifold, from which all pumps would draw. However, after extensive research, and discussions with Jason at WakeMakers (disclaimer: no connection), I'm convinced separate intakes are the way to go.

First, it simplifies layout. A manifold requires a lot of open space, particularly when you're trying to keep the pumps oriented to avoid trapped air. Multiple single inlet+pumps are a lot easier to tuck into available space.

1st, 1.5 is more then enough to support 3-4 pumps, 2" is way overkill. I use 1-1/4" for 2 reasons, its more then enough to support a typical 3-4 pump system, and there is a considerable price difference between the 1.5" and 1.25" bronze hardware.

Second, it minimizes turbulence which increases flow and thus decreases time. Multiple pumps drawing from a single manifold will cause turbulence, and the downstream pumps will likely be poor stepchildren compared to the upstream pumps, leading to annoying dissimilar fill rates.

At present I'm leaning toward 1.5 inch mushroom intakes on the hull driving one T1200 each.

A 3/4 thru-hull will support a single T1200 pump and 1" is enough to support two.

The biggest question on MY mind right now is whether the effort to use anything larger than a T800 is worth it. Why? Because after 1.5 inch inlets, and 1+ inch pumps, and one inch hose, the fittings on the bags themselves are only 3/4 inch. I understand keeping things larger to reduce the inline turbulence and wall friction, but perhaps "one inch all the way to the sac fitting" is enough. It would certainly avoid dealing with the T1200's weird threading.

How are you getting down from 1.5 to 1.125"? The Tsunami's oddball 1.125 (1-1/8") is not very common in the plumbing world, so fittings are not that common. 2nd, the more fittings added in is more places to leak as well as it's moving the pump further away from the water source.

At the end of the day, the sacs 3/4 threaded port is the bottle neck in the entire system, so 1" all the way will be plenty. Keep in mind that aerator pumps are meant to move water, not create pressure. The only way to overcome the smallest orifice in the system, would be to go with a pump that will provide pressure as well as volume.

The alternative is to fill into two sac inputs. Hey, there's a test for chpthril: Does having a T1200 driving into TWO 3/4 inputs yield a noticeable reduction in fill time? Inquiring minds want to know!

Yes, it would be 2x one pump. This will be the only way to overcome the sac's 3/4 port if filling speed is a top priority.

[Timmy!]

Wow! Those manifolds are crazy! If you could pressurize the system, you could increase flow through the existing fittings

[chpthril]

...here's a $13 solution:



Check these guys out - I had no idea you could get PVC fittings like this.

http://flexpvc.com/cart/agora.cgi?product=PVC-Manifolds

Those dont allow enough room between the outlets to mount pumps side by side, but I like the way yur thinking

[chpthril]

What I'm trying to do is overcome the inherent limitation imposed by those small 3/4 inch fittings on the sacs themselves. Many of the sacs have multiple top and bottom fittings. I agree that a one inch system (pumps, hoses, fittings, etc.) is somewhat more expensive than a 3/4 inch system, but it's way less expensive than dual pumps.

Maybe we can get a "poor man's speed increase" with a hybrid of the two. Spend a little more on a one inch system, then right at the sacs split it into two hoses each connecting to a separate 3/4 fitting. Now you'd have a full one inch system, with no artificial restrictions to limit the pump's throughput, and instead of it running into a 3/4 restriction at the sac it would see two 3/4 fittings.

Let's presume some easy numbers. A one inch aperture (hose, fittings) has 0.79 square inches of cross-sectional area. A single 3/4 aperture (fat sac opening) has 0.44 square inches. In other words, the sac's opening is about half that of the system driving it. That is serious restriction. But if the one inch system was driving TWO fat sac fittings, then the 0.79 aperture would see a combined cross-section of 0.88.

And you can have this reduction for the cost of a little bit more hose and one extra Y fitting. No wires, no pumps, no valves. You'd want to be sure to use a Y fitting, and not a T, because Y's have significantly less insertion loss. Something like this:



If I had the equipment I'd run the test myself, but I don't. (hint hint hint)

I can test that theory, but it will probably be sometime next week after we get back from Vegas. I will do it with both 3/4" 1-1/8" Y's.

[IDBoating]

Those dont allow enough room between the outlets to mount pumps side by side, but I like the way yur thinking

I know, but the spec sheet for T-series pumps shows them using short hoses on their inlet side. (They caution against permitting dips in the hose to prevent air entrapment.) Using hoses you COULD use a manifold like this one with multiple pumps. Your reliability would go up, too, since this is a monolithic piece instead of a bunch of joints screwed/glued together.

So I was only sort of joking when I posted that photo. {grin}

[IDBoating]

I can test that theory, but it will probably be sometime next week after we get back from Vegas. I will do it with both 3/4" 1-1/8" Y's.

Excellent, thanks! I suspect we may find a relatively inexpensive speed boost waiting for us in there.

Next week..? If it was me, the thrill of discovery would keep me up all night running the experiment. Looking forward to the results!

[talltigeguy]

Thanks Timmy! Bakes is just down the street and they actually use those on all the Malibu's and pepper the bottom of the hull with them. The pumps they use thread right into them. My arms are way too short to be able to get to them and shut them off if mounted in the tansom in an emergency which is why I have drifted away from that idea.

Mike, thanks for doing that. Did you post this on WW yet? I would like to see it.

The best thing I see is that the T800 is not 2/3 the speed of the T1200.

A poor man's math suggests that a 400 pound sac = 50 gallons of water. If you push that in 5 minutes, then they are all pretty close to 10 GPM, give or take. I really want to see what the Jabsco ballast puppy does. The newer ones are supposed to be 11 GPM. Be sure to let us know what model you are using when you do it. This says 11 GPM: http://www.ittflowcontrol.com/marine...last-puppy.htm

[talltigeguy]

I definitely will test it. It has a 9.0 GPM, which actually puts it slower then the T800, but, the impeller type pumps are supposed to have less flow drop then the aerators due to head pressure and lift. So in reality, the flow at the sac with an aerator, could actually be less then impeller pump, even though the ballast puppy starts out with a lower GPM rating at the pump.

See which one you have.

[chpthril]

I know, but the spec sheet for T-series pumps shows them using short hoses on their inlet side. (They caution against permitting dips in the hose to prevent air entrapment.) Using hoses you COULD use a manifold like this one with multiple pumps. Your reliability would go up, too, since this is a monolithic piece instead of a bunch of joints screwed/glued together.

So I was only sort of joking when I posted that photo. {grin}

No joke, the concept is a great idea. I have looked at having someone mold one for me, I just cant swing the cost of the mold plus the initial order. Too much upfront right now.

[majestic]

Why can't Fly high just upsize the inlet to meet customer demand?

[chpthril]

See which one you have.

The one I have I got in just last week, so it's not an old one. I grabbed that spec off Fly High's website, which was stated at 540 GPH. If I remember right, the Puppy does have a 9.0 GPM flow rate are 3.3ft of hose.

Either way, the lab results for the rated flow rate are irrelevant once it's installed in a boat's ballast system.