Watermaker & two tanks

[hoppy]

If you have more than one water tank, how do you setup you watermaker for them?

Do you have it set up so you can fill either tank?
Fill just one tank and have a transfer pump/hose?

When you are coastal cruising do you perhaps just use one tank so that the WM gets regular use and leave the other empty?

For water transfer or even wash down, has anyone added a "garden hose" connection to the boats freshwater system?

[Tellie]

This is a good question with an easy answer. Whenever we install or help an owner install their watermaker on a boat with multiple tanks we use simple 3/way valves. Usually I recommend that instead of routing your product tube to your fresh water tank, you instead route it to an easily accessed area under your galley sink. Here we would install two 3/way valves. The input from the water maker feeds the first valve, the output of one leg of the first valve feeds the input to the second valve. You now have three out puts, one left over from the first valve and two on the second valve. Use the second valves two out puts to route one line to each fresh water tank. Route the second unused output from the first valve to either, a coiled line for testing or to a simply installed small faucet at your galley sink. This way when you operate your watermaker you can simply reach under your galley sink and divert water to either tank individually or divert the water made directly to your galley sink. The galley sink is a much easier place to test the watermakers product quality before diverting to your tanks and is also a great place to easily fill individual water bottles or pots etc. for cooking or coffee, etc. This is certainly worth the extra effort during initial installation.


Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators
(954) 515-7077

[Tellie]

People with watermakers often add a fresh water wash down pump. I highly recommend that you do. This is one of the most often over looked benefits of having a watermaker on board and where the cost of watermakers start to make even more sense. Adding equipment to a boat is not cheap, taking care of a boat properly is not cheap either. NOT taking care of a boat is usually a LOT more expensive. Many of us have tens of thousands of dollars worth of equipment on the decks of our boats, winches, blocks, sails, sheets, etc., as well as fishing, diving, equipment, outboards, etc. If you can fresh water wash these items two or three times a week you will most likely greatly extend the life of these valuable pieces of equipment. This alone will pay for a watermaker many times over. Look at it this way, if you could just extend the life of the above and save, at the least, 20K in repairs and equipment replacement over a five year period, the drinking water and personal showers most people associate watermakers with are free.

Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators
(954) 515-7077

[Miguelso]

I'm also in the process of installing a watermaker and I have three water tanks. Does it make sense to connect the product water line to the line between the tanks' manifold and the input side of the water pump? I would be filling the tanks through the opposite side, but I can easily select which tank or tanks to fill. Just a thought...



Sent from my iPhone using Cruisers Sailing Forum

[contrail]

Originally Posted by Miguelso

I'm also in the process of installing a watermaker and I have three water tanks. Does it make sense to connect the product water line to the line between the tanks' manifold and the input side of the water pump? I would be filling the tanks through the opposite side, but I can easily select which tank or tanks to fill. Just a thought...



Sent from my iPhone using Cruisers Sailing Forum

I have three tanks. I have a valve under the sink which allows me to sample. The other output goes to the portside tank and the other two tanks fill from that one via a siphoning action through the tank selector manifold and its valves.. My boat is a cat, so it stays level which helps! Usually, I run the two larger tanks, the port and starboard, together in parallel, like one large tank, and keep the third, forward tank, in reserve. Very simple to install and operate. I agree with Tellie about the washdown. First thing I installed! I joke that the watermaker is actually for the boat, not the humans, but it's only partly a joke.

[carstenb]

Hoppy


your boat will ahve the same setup mine does. I plumbed the pressure hose from the watermaker into the waterline before the electric pump. I have a ball valve there so I can shut off the line to the pump and turn on the line from the watermaker.

The made water now flows backwards through the system and I can use the valves on the lines from my two tanks to switch filling from one tank to the other.

I can send you a picture if you drop me a PM with your real mail address

carsten

[leftbrainstuff]

Originally Posted by hoppy

If you have more than one water tank, how do you setup you watermaker for them?

Do you have it set up so you can fill either tank?
Fill just one tank and have a transfer pump/hose?

When you are coastal cruising do you perhaps just use one tank so that the WM gets regular use and leave the other empty?

For water transfer or even wash down, has anyone added a "garden hose" connection to the boats freshwater system?

Our liberty 458 has 4 x 60 gallon watertanks. We have a five way manifold (1 inlet = water maker outlet and 4 outlets = to each tank top).

We also have a 5 way manifold that allows us to draw water from any combination of the 4 tanks. (4 inlets draw from the bottom of each water tank and one outlet to the suction side of the freshwater pump)

We open sometimes fill one tank at a time. Other times we'll fill 2 tanks or all 4. Depends what we've consumed and how we want to balance the boat.

We monitor the tank tender to avoid overfilling. If we do overfill each water tank has an overflow through a header tank which also primes the suction side of the freshwater pump. Any overflow drains to the bilge.

The only gotcha is sizing your suction side hoses to the freshwater pump. (Not the watermaker circuit) There is extra pressure drop through the manifolds which can cause cavitation.

We have a freshwater pressurized outlet at the rear of the center cockpit. We also have a sea water washdown on a completely seperate circuit, and pump up forward for anchor washdown. Both take a garden hose.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[hoppy]

Originally Posted by carstenb

Hoppy


your boat will ahve the same setup mine does. I plumbed the pressure hose from the watermaker into the waterline before the electric pump. I have a ball valve there so I can shut off the line to the pump and turn on the line from the watermaker.

The made water now flows backwards through the system and I can use the valves on the lines from my two tanks to switch filling from one tank to the other.

I can send you a picture if you drop me a PM with your real mail address

carsten

That sounds like a good idea using the existing water hoses. I wonder though whether there is the need for the 3 way valve? Maybe just a backflow valve to the watermaker to stop the pump trying to suck water from the WM?

[carstenb]

Originally Posted by hoppy

That sounds like a good idea using the existing water hoses. I wonder though whether there is the need for the 3 way valve? Maybe just a backflow valve to the watermaker to stop the pump trying to suck water from the WM?

The valving setup I have shuts off the line from the WM to the system, so the pump can't suck water from the WM

[hoppy]

Originally Posted by carstenb

The valving setup I have shuts off the line from the WM to the system, so the pump can't suck water from the WM

I was thinking about a backflow valve but now I realise the stupidity of that idea

I wonder if having a shutoff on the hose from the WM would be sufficient. I wonder if there would be a problem trying to suck water from both the tank and WM at the same time when the WM is operating.

[carstenb]

Originally Posted by hoppy

I was thinking about a backflow valve but now I realise the stupidity of that idea

I wonder if having a shutoff on the hose from the WM would be sufficient. I wonder if there would be a problem trying to suck water from both the tank and WM at the same time when the WM is operating.

I admit I had not thought of that - Tellie?????

[hoppy]

My guess would be that the water pump would just take the WM water and the rest from the tank. Maybe if both tanks are shut off the water pump suction it might cause the WM some stress???

[SV THIRD DAY]

Originally Posted by carstenb

The valving setup I have shuts off the line from the WM to the system, so the pump can't suck water from the WM

Yes, but if you ever run the water maker with that valve shut...pop...spray...
You can not block the product water output line from the water maker during operation or you will blow apart the weak link in your product water outlet line plumbing. You have 800psi on one side and ambient on the other...block the ambient and it will rise up up up until pop.

It's just a bad idea to complicate the plumbing and suck from the water maker outlet line, the safest install is to not plumb the water maker product water into the line from the outlet of your tank to the inlet of your boats fresh water pump. Remember you have Chlorine in your tank and if ANY of that Chlorinated water gets back into the RO Membrane ...zap..Pow...Boom...your membrane is dead.

Next as your tank fills the head pressure will put back pressure on the product water line...another bad thing.

The best install approach to avoid drama down the road and that "oh **** moment" is to have your product water line go into the top of the tank, either from the fill line, vent line, or port in the top of the tank. If you have multiple tanks, you can use a couple of non-blocking 3-way valves to easily make a small manifold to select Starboard Tank, Port Tank, or Bow Tank.

[hoppy]

Originally Posted by SV THIRD DAY

Remember you have Chlorine in your tank and if ANY of that Chlorinated water gets back into the RO Membrane ...zap..Pow...Boom...your membrane is dead.

Couldn't you use a back flow valve to prevent water flowing to the WM?

[SV THIRD DAY]

Originally Posted by hoppy

Couldn't you use a back flow valve to prevent water flowing to the WM?

Sure but what happens when it fails?
Dead membranes from Chlorine or blown apart low pressure fitting spraying water on your electrical stuff?

To me it's too big a risk, because remember I take phone calls 7 days a week with the "oh **** stories" and preventing them is a lot cheaper than fixing them sometimes.