I was going to take the plunge this weekend and drill a hole to install an intake strainer for the ballast system. I was of course going to put a ball valve first to beable to shut off the intake if needed. I was wondering if anyone has had any problems with amount of pressure coming in. I got a 600psi ball valve. Also I was thinking of using pvc. Is the joints going to be strong enough?

mph PSI <BR>10 1.4 <BR>20 5.8 <BR>30 13.0 <BR>40 23.2 <BR>50 36.2 <BR>60 52.2 <BR> <BR>I think these numbers are right. Anyway, 600 psi will more than cover it!!!

Ops... <BR> <BR>Should have said use bronze valve with bronze intake. You should have strong fiitings on your hull incase you have to shut it to prevent a flood. <BR> <BR>Once you're past the first valve go ahead and use PVC valves

I ran 1" PVC up under the gunnel to the back tanks and sacks and the pressure has blown a couple joints when driving over 30 mph. Granted i am no plummer and probably used the wrong glue or something. Now i just only open the valve about 3/4 when traveling over 30mph. The flex lines up to the valve I used 10 feet of 1.5 " spa hose and that has held up fine for 300 plus hours. <BR>The first ball valve is mounted directly to the intake strainer, and i close it before i pull the boat out so the pump will hold the prime. I dont like the PVC valves because they take a lot of leverage to turn.

Well the hole is drilled. And I am ready to start plumbing. I am thinking I am going to use metal pipe up to the pump then flexible radiator hose from there. Anybody else have a better idea. The spa hose if a good idea Troy I am going to check that out.

Will a intake strainer creat enough pressure and flow to sill sacks without the need for a pump then? I realise that I would need to drive along at 20-30 to fill them but it would be easier than messing around with a pump.

I don't know Jay, I will am going to hit the water this week with my new install. I will try to get a feel for how much pressure there is. I don't think there would be enough. You would have to get a ball valve to shut when you get the water in. I don't know if there would be enough pressure to open a check valve. If you going to go thru the work of putting in a strainer, throw in a pump too.

With a scooper-type thru-hull fitting, the water pressure will fill the sacks without a pump. I have the hippo system with the electronic solenoid valves and the water pressure will force past the valves at speeds above 25-30 and slowly fill the sacks without the pump on. If you use the scooper intake, you definately want a valve at the hull.

My scupper intake strainer fills at speed as fast as with the pump on.

Where do you get the scupper intake from? <BR>

Craig - marinehardware.com has the best selection i've seen. <BR> <BR>James - interesting numbers, much higher than i would've expected. are those empirical or theoretic pressures?

That's static pressure (I hope...lol). <BR> <BR>Obviously, the scoop wouldn't be as bad as a static tube. The only point I was trying to make was that 600 psi plumbing should be fine unless you are running a boat like this. <BR> <BR><a href="http://news.bbc.co.uk/1/hi/uk/1568630.stm" target="_blank">http://news.bbc.co.uk/1/hi/uk/1568630.stm</a> <BR> <BR>reference for non-engineering people <BR><a href="http://www.howstuffworks.com/question597.htm" target="_blank">http://www.howstuffworks.com/question597.htm</a> <BR> <BR>The following site has similar numbers (mine were based on metric water...lol) <BR><a href="http://www.tflx.com/pdf/marspd~1.pdf" target="_blank">http://www.tflx.com/pdf/marspd~1.pdf</a> <BR> <BR>Oh right, the question you asked.... theoretical! <BR>

Well I was going to tee into the raw water intake to run to a pump to fill my fat seat and fat sac but I might just fit a scoop intake and give that a try as its a 5 min run at 25-30 mph to our ski zone anyway so that should force enough water in with out the need for a pump and then it will drain nice and easy when on the trailer.