Check valve for 3/4" plumbing

Doug · Posted: Dec 12, 2005 8:29 am Post subject: Check valve for 3/4" plumbing

Where is the best place for check valves that are small in size for ballast system. Using 3/4" plumbing.

Doug · Posted: Dec 12, 2005 4:24 pm Post subject:

I just came back from Home Depot and Lowe's. On all the DIY ballast threads, I have seen both spring and swing type check valves. I will be using a Simer pump to fill and empty. I will be using the configuration to fill from thru hull, empty thru overflow, and vent through overflow. What is the best check valve for this?

gmarkham1 · Addict Joined: 10 Sep 2003 Posts: 505 City: janesville

Doug,
with a simer reversible pump you can fill and empty through the same hole(I have the same pumps and I fill and empty through the thru-hull. Just an fyi

Doug · Posted: Dec 13, 2005 5:12 am Post subject:

The sacks in the back are on the floor in the open, so I can watch them fill and empty. Both fill and empty will be through the thru-hull fitting. In the front of the boat I will have a sack under the front bow seating. Since I cannot see when it is full/empty, I would like to have overflow and empty thru a side hull fitting.

gmarkham1 · Addict Joined: 10 Sep 2003 Posts: 505 City: janesville

The overflow is a good idea.
When emptying, the pumps make a notable difference in noise when the sacs still have water in them and when they are empty, I think you may need an additional pump or a extra plumbing in able to to empty through your overflow(which would make the case for using two aerator pumps instead of a reversible pump). Just some food for thought.

SuprAir · Outlaw Joined: 10 Jul 2003 Posts: 180 City: Columbus

Cracks me up when folks assume you don't know what you're doing when you ask about check valves in a primer pump system.

Anyway, I'd steer away from spring-type check valves. The pressure required to open them will cause serious drag on emptying and venting your system. A "swing-type" check valve offers less resistance and should be more durable.

I've seen a lot of the brass 3/4" swing checks in systems, including those from manufacturers. My 01 SAN has a couple of them, plus I think the multi-pump system from Make-A-Wake utilizes brass checks.

I'm seriously considering putting pvc swing checks in my system. (http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/8242/cid/2083) I don't know if they'd be as sturdy as brass, but it seems like they're better suited for boat ballast systems.

make-a-wake · Newbie Joined: 18 Nov 2004 Posts: 25 City: bowling green

SuprAir

You are right we use brass check valves on the RCII and RCIII. They allow auto swith to fill from below and empty out another line out the side. The same ones we use are sold at Lowes, they must be mounted flat to work properly. We use 3/4 whale flap check vlaves in the overflow lines for bags, they can can be hung in line with the hose at any angle. The same ones we use are sold at www.boatersworld.com 3/4" whale check valves.

Cyclonecj · Soul Rider Joined: 12 Jan 2003 Posts: 338 City: Atlanta

Home Depot sells the same one for five bucks