Ballast System Design and Flow Rate Questions

After many days of research and actually installing my very own ballast system I am ready for an upgrade and was hoping you folks could give me a little advice. Currently I have a 2 Simer pump 3 bag system that runs off of the Raw water intake. The two pumps run in parallel feeding a PVC manifold. Ball valves control flow to each bag. This has been a great system and has saved me oodles of time and frustration. But there are a few things I always said I wanted to do differently. Below is what I would like to do.



As you can see it will be a 3 pump (Simer Reversible) system in which each pump will control a single bag. I will have 3 DPDT switches to run the pump in Forward and Reverse.

I plan on installing a 1 1/4" Bronze Thru Hull Scoop Strainer. I will connect this Intake to the 1 1/4" inlet side of my manifold. Then I will connect each 3/4" outlet to the suction side of each pump. And then obviously connect the discharge side of the pump to its own bag.


The manifold, I plan on having machined out of aluminum (I know a guy).

The question I have is this, will the 1 1/4" inlet on both the manifold and the thru-hull be large enough to supply a sufficient amount of water to the 3 pumps? And on the flip side, should I expect the draining to be slower than filling or will it pretty much be the same as filling? I was thinking that pump performance would go down since all 3 pumps would be creating pressure inside the manifold when draining, but I guess the same could be said for the fill side as well. I just don't know. Any thoughts?

I also have one other question about line size and fittings. It seems that when using an ID of 3/4" (which seems like the obvious choice being that the Simer pump connections are 3/4") sets the stage for some major restrictions in the plumbing. For instance any time a 90 is placed in the line, significant restriction occurs. I've read several posts referencing Flow-rite valves and fittings. Are the Flow-rite fittings somehow less restrictive than what I can buy at Home Depot?

So really my question is, what does everyone recommend in terms of line size and fittings when using the Simer pump?

From all the research I've done it seems that the type of line really doesn't matter that much. PVC pipe, Flexible PVC, Spa tubing, it all seems to perform pretty much the same. But what does seem to matter is the size. So if you've been through this I would love to hear about your experiences.



Sorry for the length and thanks for any help you can offer.



-Bo

I know Craig will put his .02 in about the Flow Rite valves, they are the best thing going, but IMHO you don't need any valves with that setup. The Simers don't flow when they are off. I'm way to lazy to do the math, but I would think you would be fine with 1.25 inlet, even with all three pumps running. Even if you burn an impeller, they're only six bucks for those pumps. As for tubing, you need to use reinforced hose or you'll suck it flat with flexible impeller pumps. FYI, Toyota used a flow switch with their ballast setup on the X22, it was basically the same thing you have, but only one bag. They had a through-hull overflow to prevent overfilling and a flow switch that turned on a buzzer when the bag was empty. They used that setup in '99 with Water Puppy pumps. I'll find out what kind of switch they used and post it.

Psyclone,

I also believe I don't need any valves, with the exception of the Emergency shutoff of course. I'm not too worried about over flow since in my current system I have to watch them anyway. So I'm used to it. As an additional enhancement I'll probably hook up a small micro switch next to each bag that will either set off buzzers of some sort of LED.

Thanks for the post.


-Bo

i think you'll be fine with 1-1/4. your drain time may slow down if you're underway due to the scoop intake. also, when Simer pumps get a little worn, they can flow a little water when turned off.

Trace,

Thanks for the tip on the Pump. What kind of volume are we talking about. Does it take a couple of years for a small trickle. Or, is it more like a stream.


-Bo

Trace,


What would you suggest to take care of this problem? I don't really like the idea of putting in electric valves (too bulky and restriction a plenty) and the Flow-rite valves are...well... too manual for me. Any ideas?

By the way, thanks for the article on the automatic ballast system. I would never have gotten my first one built without.

Have you had significant problems keeping your valves open all the time?


Regards,

-Bo

I wouldn't worry about it. I happen to use aerator pumps for speed, I use sprinkler valves to seal the water inlet when I am running without turning a hand valve. If I were using impeller pumps, I wouldn't use valves. Either method will restrict flow ENOUGH. Boats always leak a little, that's why you have a bilge pump. You could replace the impellers every season if it bothered you. A bigger problem is what happens if you have a failure of your system inside your boat, if a bag or hose splits you will have lots more water in the bilge from inside the boat than from outside it. I use high quality hose in the bilge, not the clear stuff from Home Depot, but bilge rated stuff from a marine store. You can use all the fancy pumps and valves in the world, if you skimp on hose, you could sink your boat. The hose that came on my Toyota was so tough I had to cut it with a hacksaw. I know Trace used garden hose and pvc in his excellent article, that works fine if you're on a budget and if you take the time to inspect the condition of the components over time, but if you have the means to buy a 50k boat and 100$ valves, and spend 1k+ for speakers, buy some good bilge rated hose!

Psyclone,

Point taken regarding line quality. Thanks for the input.

Even though I think the PVC line I've used will hold up, I've been pondering the thought of using a better grade hose. How much should I expect to pay for good hose?

And by the way, if the hose was that tough how in the world did you get your fittings in?

Thanks,


-Bo

my pumps are about a year old, and if i leave a valve open it will drain a 550 in about 3 hrs. and don't use cheap hose.

and for the record, i recommended heavy duty garden hose or reinforced vacuum hose, and PVC pipe (not hose).

and i don't know of any better valves than the Flow-Rites

Trace,

That's interesting. So I take it you Manually close your valves between uses? How long would you say you run your pumps on average?

Sounds like I might be back at square one again. If I'm going to have a problem keeping my bags full without the manual valves and the valves are still neccesary then the system is no good to me. The whole point of this excercise is to get rid of those manual valves.

Thanks for the info.


-Bo

Hey Trace, I didn't mean to insinuate that you were a cheapskate or anything, just cost conscious There is a huge gap in the people that post on this site, some are people struggling to make ends meet, some have more money than God. I try to do it inexpensively (and safely) when I can, as I know you do.

When you say that your Simer leaks 66 gal over 3 hours, you mean that it is running back through the pump out the fill through-hull due to the pressure and gravity, right? Is that also true when the boat is moving? I would guess that If the worst happened, and your bag supply hose split, you'd have a lot more water coming into the bilge from your sacks than from outside the boat. Thats my point. I think Bo hears "leak" and thinks that it is coming into his boat from outside. IMHO he is in fine shape with no valves, as long as he has a cutoff when the boat is not in use. BTW, I appreciate all your help over the years.

Here is a link to the expensive stuff, over 2$ a foot. It sucks to put fittings in, heat gun helps.
http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&classNum=146&subdeptNum=145&stor eNum=11&productId=

It is 148 series hose in case the link doesn't work, rated for critical bilge applications.

If you want to see a factory schematic for a similar setup, look at the How_To page on my site, there is a large PDF with details on the Toyota system. They used the same setup, no valves other than a hand valve.
www.cyclone-cj.com

nah, i'm a total cheapskate. i just found (to my dismay) that cheap hose wouldn't work.

i shut off the valves manually when full. i probably run my pumps an 45 min a day at most between filling, draining, and tuning.

the unintentional draining actually occurred while doing pretty much back-to-back sets, so it was likely sucked out by the impeller. (Bernoulli again)

anyone else running Simers without valves?

anyway, i think where the water comes from if a line leaks depends on many factors... engine running or off, location of the leak in relation to the waterline, etc.

also, i have to say thanks to CJ, Ty, Dane, JumboJoe (where's he been?), and many others on this board for all the help & insight over the years. i feel the love!

nice site too, CJ.

Very cool. I use the simer and don't have any drain as of yet. I don't think there will be any issue as when the engine is running faster and the impeller is pulling more, more water will be pushing up into their from the scoop. it should cancel each other out.

i don't know if you want to change out your sacs but letsgoride.com can use 1 inch nozzles.

I've used a simer pump with no valves for one year. One pump for three sacs. No leakage (backflow) here.

Trace,

So, do you think that the water leakage is actually caused by the engine impeller sucking the water out of your bags and not so much that the impellers are leaking from use?

Since I'm adding a new thru-hull for the Intake what do you think the chances are that water will be PUSHED through the pumps and into my bags. This would be very bad since I'm using the Fly High bagless sacs. They would probably explode before I noticed them getting larger.

Backflow = empty bags small wake. Flip switch and viola problem solved.

Forwardflow = exploded bags and possible engine damage. Not to mention the possibility of hull damage. Yikes!!


-Bo

how large is a normal drain plug fitting. can you use this as your through hull fitting or is it too small?

Where is the best place to pick up a thru hull water pickup? Cheapest?

i bought some stuff from marinehardware.com. seemed to be mfgr-direct sales, very nice people, good product, $25 min order.

Bo- i don't know, Matt & Ty's work fine, but i wouldn't do it myself just due to that incident. it may have something to do with a leak in my circuit too, because i'm getting air bubbles in my fill lines from somewhere i haven't found yet. i agree with all your concerns. good luck.

http://www.marinehardware.com
word

Bo, if you are using any type of impellar pump you should always use a vent hose off the bags. Those pumps can produce enough pressure to do major damage when the sac is in an enclosed area and being filled beyond capacity. There was a post a while ago about a new Supra Outback factory ballast system that had the vent hose blocked and it cracked the deck of the boat when the bag overfilled, nasty. Supra being the awesome company they are replaced the boat from memory.

Darren,

The overflow idea is sounding more and more like a neccesity. Thanks for the input.

The only problem is how do I control when the bag starts overflowing? If it overflows too soon then I don't get a full bag. Of course if the pressure inside the bag never becomes great enough then the bag will never overflow and only expand. Sheesh, what a headache!!

Does anyone have any experience in this area using the fly high "bagless" sacs?



Trace:

I'll bet you have Nightmares about ballast questions from Newbie's. Sorry to add to your horror. But, I very much appreciate the advice.


Based on this new information I think I'll re-think this thing a bit.

But, to sum it up here's what I think I've learned. The design in the pic is fine as long as I use good bilge rated hose and add overflow's to all reservoirs. I might have a problem with back flow(eventually) but to me that's ok. I just need the overflow's to keep from bursting a sac (Don't laugh that's not funny - ). Is that about it?


Again thanks to everyone for the input.


Regards,

-Bo

Bo as long as the overflow pipe rises above the bag it will be fully filled, in my boat the front sac will still pop up the bow filler cushion as the vent is flowing. My vent comes out next to the driver so I can see when the bag is full and I can turn the pump off.

Darren,

Currently I fill and drain my bags with the Openings facing down. From what you are telling me with the new configuration I should have the bags turned back over facing up. Is that right? Are there any problems draining with the bags facing up?

Thanks,

-Bo

Yes, but there is a cheap fix. (thanks Pete from Letsgoride!) Buy some cheap 1" OD clear vinyl tube from Home Depot. You can stick a long 12" or so piece onto a 3/4" barb fitting and jam it into the sack. The barb fitting expands the tube just enough so it makes a secure watertight fit if you stick it in a standard fat sack inlet. I have used a short piece on the inlet to a Fat Seat (lower rear) with kids jumping on it and my fat butt lounging on it and it hasn't leaked in two seasons. Talk about extreme duress. Makes it easy to remove the seat or sack, give it a twist and it comes right out. No more blue waterbed thingys for me! You could put a hose clamp or wire tie on it if it were in a remote location and you didn't want to worry about it popping out, but it won't.

I don't believe Supra was using an impeller pump, I think that the damage was done with an aerator pump. Even scarier. That is why I abandoned my idea of sacks under the front seats. Full sack in the walkthru for me! It's cheaper than the factory bow filler cushion, or so I tell my wife.

less than 1 psi over the area of even a smaller sack could be over 1000 lbs of outward force.

the hose-in-sack thing works great too, esp if you perforate the hose. 3/4 barb fitting into 3/4 ID x 1 OD perfd hose, and all that into the 1" nozzle on the sack. put a hose clamp over the whole thing & it'll never come out again.

also, the height of the overflow to the top of the full sack determines how much pressure will be in the sack before it overflows. it's hard to make locker sack overflows work well because of this.

did that make sense? - it's gettin late -

i think i actually stole that perforated hose idea from you, CJ!

The only thing I have come up with on my own is the idea of sucking string through your tower with a shop vac to run tower speaker wires, and I probably wasn't the first. I was ONE of the first, anyway. The rest is all totally, willingly and gleefully plagiarized.

Trace, just though of something after reading your post about the locker sack thing, I don't have a ski locker, or a ski, so this is totally original. If you used one of those cheap Home Depot (I love that place) ABS check valves that is basically a tube with a ball and spring in it, and just let the overflow dump in your bilge, that may work as a pressure relief for a locker sack. They suck as check valves for other reasons because of the pressure that must be overcome to push the ball off the seat, but they probably would leak enough to prevent overfilling. Until the bilge pump gives out.
I'm still going to find out what switch Toyota used for the low flow alarm.

Trace, CJ: Thanks for all the great help. You guys have pointed out a lot of things I wouldn't have thought about and probably would have cost me in the end.

One last question about the over flow vents.

In your opinion what should the maximum rise be?
And does hose size matter? Would 1" hose be more likely to overflow than say a 3/4" hose?

Well, I guess that's 3 questions. Sorry.


Thanks again,


-Bo

I personally think maximum rise issue is a bit of a red herring, so I don't think a dangerous amount of pressure could be generated in a vented sac.

Was the Supra ballast system feed with a scupper type intake? That could generate an enormous amount of force and is probably more likely to do the damage rather than the force from the pump.

The vent doesn't have to come off the top of the sac as long as the hose rises above the level of the full sac it will only vent once the sac is full, but a vent off the bottom will not automatically burp air out of the bag which is a bonus.

I put new connections into my bags using skin fittings like you would use through a hull, just cut a hole 50% smaller than the shaft of the fitting and stretch hole in the bag around the head fitting and tighten the locking nut down, I put 1&1/2 threaded fittings into my bags this way, it was easy and no leaks.

No the size of the hose does not matter as long as the pipe can keep up with the rate of flow from the pump, I will do some calcs at work tomorrow to work out how much pressure the sac would carry with different sized vents, I use 1/2" with a 3800 GPH areator pump, it's probably a too small but the pressure created by that type of pumps is small and I can see the vent running when the sac is full.

Can you post a pic of the bag modification? sounds like a great idea, worthy of theft and exploitation.
The Supra/Moomba systems I have seen were fed with a scupper, to a Rule 1100 feeding a PVC manifold with sprinkler valves feeding each sack, Drain pumps on each bag. I don't know if there were separate vents or they were using the drain pump and line as a vent. Aerators are wide open when not running, for those that didn't know that already.

Darren,

Thanks for the post. I'll be looking for your results.


Thanks,


-Bo

WARNING: This is long, boring & has some maths......

Ok, I’ve had a think about the vents and this is what I have come up with:

Using a simer 8512 pump and pipe with the following specs:

Peak flow 10 GPM @ 0 foot head
Max Head 17PSI •••••• GPM

Pipe between pump and sac 3/4” ID 20 foot section
1. Pipe between sac and vent 3/4” ID 10 foot section
2. Pipe between sac and vent 1/2” ID 10 foot section

Vertical rise from Pump to vent 3 foot

The pressure in the sac is found by calculating the pressure generated by the pump at
the flow rate of the system. The flow rate is found by intersecting the pressure of the
pump vs the total loss of the system.

Total loss = flow loss from the pump to the sac + vertical rise from pump to vent +
flow loss from sac to vent. Losses in the pipe sections varies with flow rate, vertical
rise loss is static.



From the table we need to find where the pressure from the pump = the total loss in
the system.
With a 1/2” Vent about 7GPM @ 5PSI.
With a 3/4” Vent about 9 GPM @ 4PSI


Note: These figures only hold true once the sac is full and the system is venting, vent
pipe size will have no effect on speed of sac filling.

With No vent the flow rate will be 0 so the pressure in the sac will be 17PSI

nice! i assume the blue squares are the range you would expect to see in normal operation? (total loss = pump head) do you still think you couldn't generate a dangerous amount of pressure? 4 psi in my locker sack would be around 8000 lbs!

Ralph, back to your bag modification. Did you use a typical through hull fitting and jam the fat part into the bag, then tighten down the nut to make it watertight? This is very interesting, as it would really make a big difference to those of us cheapskates that don't want to buy custom sacks.

Trace, what do you think that 8000 pounds actually means? If you drove your truck onto your sac would it lift the truck off the ground? Do you think an 80 watt low pressure high volume pump can produce enough energy to produce a load that high?

Psyclone, yes exactly, except it's not so much jamming it in as stretching the hole in the bag around the head and it then forming back around the shaft. I've got 1&1/2" fittings in my bags, I cut about a 1 inch hole and streched the head through (about 2" diam) leaving the thread part hanging out of the bag. I might have a photo at work, I'll post it tomorrow.

Here's a pic of the fitting, it's not a good shot but gives an idea.

Jeez, that thing looks like a firehose! That's got to help fill times. I'm going to mod my extra Fat Seat the same way!

Darren - the way i see it, pressure is pressure, and the problem is when the sack fills a rigid area and has nowhere else to expand. so yes, i believe that (given a constant volume) my little pumps could lift my truck. my ski locker is ~1900 sq in exposed to the underside of the floor; when you apply 4 psi over that much area, that's 7600 lbs bursting pressure trying to separate the floor from the hull. you have some things working for you like the weight of the floor, deck, and any sacks on top of the locker, and the presence of the access door. my access panel is about 10"x42" - would take over 1600 lbs to hold it closed at 4 psi. in reality what happens (i've seen it) is the sack will probably push the access door open, find a sharp edge, rupture, and you'll be pumping water into your bilge.

great idea for adding a nozzle to a sack, BTW!

The Simer 8512 actually puts out 8.5 gpm max not 10 gpm as advertised! I tested it. The 10 gpm is just marketing *&&^%%#@ trying to keep up with Jabsco….

Think about it... 8.5 gpm and runs on 12 Vdc... model 8512? Coincidence?

I think not! Bastards! Do they think that I have the time to wait for their pump?
Did you try it on 14.4 VDC? That seems to be the "stereo dude" voltage that they rate all the amps on, closer to what the alternator actually puts out, no load, ideal conditions. Like you said, marketing BS.

I hit 8.6 gpm with open discharge, really short intake hose, no lift, and the charging system running (so about 13.75~14 Vdc)

I phoned Simer and asked to talk to their test engineering so thatI could learn from his "skill" at getting the pump to do 10 gpm. No one returned my call...

I would be very interested to know what they had to say.

-Bo

where can I buy a reversable simer online?

I dont know where online, but I stumbled upon them at blain's farm and fleet 53$. they are packaged as a floor mini-vac pump.