Design Question

[bobbysky]

I'm working on designing my ballast install. If I just have a fill and drain line and no dedicated vent line, will this idea work???



My pump will below the back so I don't think I will have any priming issues even though it's not connected directly to the bag.

[majestic]

I am by no means a ballast expert by my first pass would say air will get trapped and the bag will not fully fill.

[bobbysky]

The arrows are check valves too I meant to put that up to.

[chpthril]

What's this line for?

2 things I see: The sac will accumulate air without a vent line located off the top of the sac. 2nd, that diagonal line i'm asking about looks as if it would act as an over-flow when the sac is full. This is a good thing, but with a sac a large as a 750, the sac may begin to purge water before the sac is full. Will the thru-hull be higher then the top of the sac when filled? If so, then you may net experience pre-purgeulation If you are using aerator pumps on the drain line, then you may not need that diagonal line bypassing the pump, the aerators will pass water when off.

[da.bell]

Are you going to be bringing in warm/hot engine water?

Don't think the bag will do well with that.

[bobbysky]

Basically I'm trying to make this as clean as possible. The diagonal line was there to try and bypass a top vent. My buddies supra has two lines coming into the middle of his bag and no top vent. I'm trying to make mine so you can't see hoses all over the place when you open the back compartments.

And chp, I hope my through hull is going to be above the bag. I'm wondering if I should get a mini enzo sac made that holds 750lbs. To keep the height down a bit.

[chpthril]

What year is his Supra? If it uses reversible pumps, then I see why it would need a line like that. Also, I read a lot of post from Skiers Choice owners who complain about their sacs filling with air and not water. End result, the add a vent on top of the sac and a thru-hull.

I like the way ur thinking, having a clutter free, clean install, is definitely a worthy goal. If you switched to reversibles, this would allow for a 2 connection setup like you have drawn - fill/drain from bottom, vent from top. You can do a system without a vent, i'm just worried about blowing the sac up like a balloon and it bursting. Heck, even the aerator pumps will pressurize the sacs, and they are not a positive displacement pump like the Puppy's are.

[bobbysky]

I figured out how I can make it clean(er) with using 3 hoses.