Teeing into Plumbing for Katadyn 40e Watermaker

[Matt Johnson]

I'm installing a Katadyn 40e next week and need to tee into an existing 3/4" thru hull after its strainer below the waterline (after a seacock). The 3/4" line will be reduced on one side for the 1/2" water line to the 40e.

I was looking on Mcmaster Carr's website at a bronze tee, reducing bushing and three barbed fittings, but wasn't sure if bronze was the best choice. Would you use bronze or plastic?

Also, do I need to worry about any of these fittings and hoses being for potable water? I have never heard anyone mention anything about what issues the hoses may cause.

Anyone else have any suggestions for teeing in?

[daddle]

Bronze or plastic (Marelon) doesn't make much difference. I'd use plastic for weight savings. Tubing ned not be for potable water...but why not?

One problem with tee-ing into and sharing a thru hull is that one device may suck water away from the other device, then air, rather than from the sea. You should evaluate this possibility. I would not tee into an engine cooling inlet without careful designing (engineering).

[sailorchic34]

Either would be fine. I would tend to lean toward bronze, as I trust it more below the waterline.

[Tellie]

Teeing into an existing thru hull is done a lot with smaller water makers. What is important as daddle mentions is what other devices the thru hull serves. Many water makers production is effected by sharing a thru hull with a device that demands a lot of flow like an A/C. With such a small water maker as the 40E it can make a difference. Tapping into an engine intake is just not a good idea at all. As far as bronze or Marelon I would think it a minor issue and a personal choice. It's more important of course to have a quality seacock that is maintained and works. There are no issues I've ever had with decent quality braided hose and fittings for the intake plumbing.

[Matt Johnson]

I can run from an old sink thru hull instead of where I was going to tap into, but this would require the hose to be about 35' long and rise about 4'. Would this be an issue with the 40e? Also, this thru hull is less on center than the 1" engine thru hull I was going to use.

With all the solar I'm installing, I don't think I'll be running the engine and the water maker at the same time, but until I'm actually out there, I don't know how I will want to use this.

[donradcliffe]

Again, don't use the engine intake for the watermaker--in spite of all your solar, you will want to turn on the watermaker when you are using the engine and have abundant power. Sink drains are not too good an idea either, as the membranes can be killed by oil, chlorine, or iodine. Make damn sure that any bronze fittings are really bronze and not brass, which self-destructs in salt water.

[Tellie]

Many sink intakes are located high on the hull. The deeper the intake the better for watermakers. I'd be curious how you are using 35' of feed line hose on a 34' boat. Even with a few turns and such you may want to revisit your planned installation route. A 4' lift is relative to the waterline. It would seem to get 4' above the waterline would be unlikely. Definitely make sure you use bronze not brass. Also as Don suggests, many times a sinks drain is very close to it's intake because it's easier to plumb originally. Cleaning chemicals used in sinks can damage a membrane. Again, I'd advise against tapping the engine intake. But I know the manual for the 40E actually states using the engine intake I still think the best method is always a dedicated thru hull.

From the manual...

"4. Install Seawater Intake Plumbing: There are two common approaches to providing the seawater intake circuit:
• Tee into an existing seawater intake (e.g., cooling water">engine cooling water or manual seawater pump inlet).
• Install a dedicated thru-hull for the watermaker."

[Jon4399]

I'm planning to install a watermaker with a "T" off the AC thru-hull. I have a 16K AC unit and can not run it while at sea. Conversely, I would never operate a watermaker while at a dock. (I only have a Honda EU2000 generator and don't believe it will start the AC). The possibility of both operating at the same time could be solved by a switch which only allows one or the other to operate, but in my case, I'll just know better.

[sailorchic34]

In a perfect world the water maker feed wants to be at the bottom of the hull. This places it away from the surface where oils and other stuff tend to collect.

So use the engine seawater connection for the time being (when the engine is not running) and put a dedicated thru hull in next time you haul out. Of course you could put a larger engine thru hull connection in at haul out and keep the holes in the boat to a minimum.

Ditto, brass should not be used as the zinc content is too high. The zinc will leach out and cause brittleness in the remaining copper.

[Matt Johnson]

Tellie,

35' may be a bit of an over estimate, but unfortunately it would have to run from the opposite side of the V-berth to the rear lazarette via a strange maze. Sabre ran a half fiberglass pan that makes running any wire or hose a bit difficult on this boat.

I'm thinking installing a dedicated thru hull maybe the best option. I could mount it right by the engine's one close to the center line. I just wanted to avoid as many holes as possible. I'll give Spartan a call about getting another seacock tomorrow.


Thanks for the help,

Matt