Plumbing and Valves

After figuring out which system you want to use and sizing the pump(s), start looking around your boat's interior. The layout of your boat will help you decide what size and type of ballast reservoirs you need and where you will be able to fit them. The location of your ballast should have nearby access to areas where you can hide the plumbing lines. Making holes in your boat's floor, hull or deck to accommodate the system can be risky and should only be done by a professional. This can decrease the boat's resale value, compromise its structural integrity and cause other problems.

Run all plumbing as low as possible in your boat. Keeping everything low makes life easier for your pump because it won't have to lift the water as much when filling or draining, and it helps your system stay primed. If your pumps are below the reservoirs, siphon effects will maintain prime in the system.

Make use of regular white PVC pipe as much as possible; it's cheap, durable, and doesn't kink or collapse. Where you must use hose, use heavy-duty garden hose or spiral ribbed vacuum hose and route to minimize kinks. Vacuum hose is designed to withstand negative (vacuum) pressure. It usually has plastic spiral ribs as shown here.

Check Valves

Diverting Valves

A 3-way diverting valve switches flow from one inlet to one of two outlets. It is used only on the non-reversible, single-pump system show in Schematic B. These valves can be a little pricey, but they are required for this system.

Reservoir Lines

It's a good idea to label all inlets and outlets at the reservoir so you are not trying to determine what pipe does what if you have to disconnect something a few months later.

The hose sections should be just long enough to allow the ballast to move around a little without pulling the hoses loose. The blue fitting shown is a waterbed-to-garden hose adapter, which comes with most water ballast and is available at any waterbed store or Wal-Mart. They sometimes have to be purchased as part of a kit.

Note: ¾" NPT male fittings will seal to female garden hose fittings (right), but garden hose male fittings will not seal to female NPT fittings (left).

Fill Lines

For the water pickup line, tee into the raw water intake in the bilge as close to the hull as possible. This connection can pretty much be anywhere upstream of the engine, but the closer to the through-hull fitting the better. The flow is also less restricted if it is placed upstream of the transmission cooler. The tee fitting used here should have barbed hose connections to fit the raw water intake hose (usually 1-1/4" ID) and an appropriately sized threaded fitting on the side.

Place a ball valve in the pickup line very close to the existing raw water line as shown. This will allow you to isolate the system from the engine in case there is a problem. This valve is only intended to be an emergency shutoff, and will remain open unless there is trouble. Be sure to use a ball valve here because it is much freer flowing than other valve types. Standard water spigot valves are not recommended.

If you install the reversing-pump system, this will be your fill and drain line. During draining, the water will either exit the boat out through the raw water intake if not running, or be pulled into the engine as cooling water if running.

There is a remote possibility of starving your engine of cooling water if you have an extremely large fill pump, but this should not be a problem in the majority of systems. You may want to test for this before going any further with the installation by connecting your fill pump to the raw water intake and pumping water overboard while the engine is running. Regardless of whether or not you perform this test, you should always watch your engine temperature gauge whenever you use the system to be sure there is no overheating. This is very important because overheating can seriously damage your engine.

CAUTION: Do not place the tee downstream of the engine. This will fill your ballast with extremely hot water and may damage it.

Some boats are manufactured with onboard ballast systems built in. For example, the Malibu Wakesetters have the Malibu Launch System (MLS) set in the ski locker with independent fill and drain pumps already in place. These systems may already have a water intake and draining system set up. In these cases, you can utilize some or all of the built-in system instead of performing some of the tasks outlined in this article.

Manifolds

Schematics A, B and C each show shut-off valves right before the reservoirs. These are valve manifolds as indicated by the black dashed boxes around them. A two-pump system has two manifolds, one fill and one drain. A single-pump system has only one manifold that serves both functions.

The valve manifold allows the controlled filling and draining of each reservoir independently. You can completely shut off circuits you do not want to fill or drain, or you can throttle circuits down so that all the reservoirs are full at about the same time.

To change the number of reservoirs, just add or subtract reservoirs and corresponding valves in the manifold(s). Locate your valve manifold(s) where you can reach it from the driver's seat, but also where they are somewhat hidden. A good manifold location is shown here. Be sure to label which reservoir each manifold valve controls.

Drain Lines

If you are installing the reversing-pump system, you will not need a separate drain line. The reversing-pump system uses the fill line for both functions.

If you're not using a reversing-pump system, tee your drain line into the existing bilge drain near the hull outlet. Place a check valve on the existing bilge hose, upstream from the tee, to keep water from draining back into the bilge as you drain your reservoir. If you did not spring for the self-priming pumps, you may also need to place a check valve on the drain line downstream from the drain pump, but upstream from the tee, to help it stay primed.

Previous

Next