Tag Archives: powersurvivor 80E

watermaker

Powersurvivor 80e out of the box

Ok the book isn’t included in the box but everything else is plus a user manual. I’ve put the book (standard paper back – and a good read) into the photos to try and give an idea of scale as in most other photos I couldn’t work it out myself. I was surprised how substantial the pump and motor are. They are by far the heaviest items in the box and although I was thinking the canister would be the hardest to stow its the pump that I’ve got to think about. Its not just its size but also weight and how much vibration it will cause.

The unit comes with plenty of chemicals to get you started as well as fixing mounts and a gadget for measuring the salt content of the product water.

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Kataydn powersurvivor 80E

watermaker watermaker

In my ealier post I covered the options I had in terms of buying and fitting a water maker for my yacht. In the end I went for Kataydn’s powersurvivor 80E. The balance of price, power consumption and output was right for me. I imported the unit from West marine in the US. These units are very heavy and west marine offered the best postage to the UK and price – to make the deal even better use this dicount voucherwatermaker to get 10% off this and all orders at WestMarine.

In all I saved around £1000 against the local prices meaning I went for the 80E over the 40E.

Its worth keeping an eye on the prices on offer the unit I bought 3 months ago is now listed at a huge $840 more than I paid for it. Most likely due to currency flutuations but I’m sure mine was on special offer, its likely to be again.

The powersurvivor does have some draw backs, principally the price of the replacement membranes (non standard in the RO industry) and motors etc should there be any problem outside of the 3 year warranty. Second hand prices seem to stand up well so as long as its looked after I’m sure I could get 50% of my money back should I want to.

There is some excellent information covering installtion and maintenance and even a repair video for the powersurvivor 40e over at Ishipaco’s website, if you buy one its well worth checking it out. You can find the offical manual for the powersurvivor 80e here on the downloads tab.

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diy watermaker

What about a DIY water maker for your yacht ?

There are plans on ebay which give you parts list for building your own engine driven or 12v water maker. I have bought these and they do give you a good run down on the construction process, a list of parts etc. RO units are popular in the US and not just at sea, homes in the US also make use of the technology so there are lots of US suppliers to the market.

To give you an idea of how simple an RO unit can be I’ve created the following diagram. Its without pressure gauges, sea cocks, selecting values, Y values for diverting supplies etc but the main components are there.

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A great thing about building your own would be the supportability (you build it you can fix it from industry standard parts) is the fact you can tap into this well developed market for membranes, filters, canisters etc.

How does a Water Maker work ?

A water make is actually very simple. It just requires sea water to be pumped through a membrane such that product water is extracted and waste brine discharged. What brings complexity is the fact that this is done under pressure (circa 800 psi) which requires both energy and some engineering (to support the pressure).

Sea water has a has a salinity of about 35,000 parts per million drinking water is under 500 ppm (parts per million). The membrane blocks the larger salt particles from passing through thus filtering out the salt from the water. Membranes produce around 10% product water with 90% reject (or brine).

What do the different parts do ?

The water strainer and pre filter simply strain out organic mater and large particles from the system. As you go from left to right the filter targets smaller particles for removal. You can employ a number back to back going from say 10 micron to 5 micron, to try and protect your membranes from debris.

Supply Pump

The supply pumps job is to keep your high pressure pump primed and to keep water flowing such that the high pressure pump doesn’t run dry. The supply pump should be rated to exceed the flow rate requirements of the high pressure pump. On commercial water makers the pumps are often self priming (so this could well be an option) and capable of drawing water directly from the pre filter.

High Pressure Pump

The high pressure pumps is where it gets interesting. These are triple plunger (triplex) positive displacement pumps. Google them up and you will see they are used in everything from high pressure car washers to the oil and gas industry. Manufacturers such as Cat (models 277, 241, 271) and Wanner are worth checking out. The pump needs to match the requirements of the membrane, so the GPM (Gallons Per Minute) of output needs to be right.

Also you need to get the pump material right (and at the right cost).

The pump needs to be driven. Hence the motor. And a decision, 12v, 240v, 120v or engine driven pump ? All have there pros and cons and you need to decide how complex a system you want verses the old problem of power management and cost!

Pressure Vessel and Membrane

Simply a vessel that contains the membrane and pressure! For membranes check Filmtec Membrane SW2540 (SW stands for sea water). These are pretty much stock and of course need to match the length of the housing (pressure vessel).

To Build a DIY water maker ?

Matching the pump, motor and membrane with your desired ((or acceptable power consumption) is one of the key challenges. Particularly If like me your trying to match match a 12v motor to a suitable pump. If you look at Ech2OTec’s entry level unit it requires 19.8AMP’s at 12v which is very good for 32Lt output at $4490 but many other motors require twice that power. For a diyer and noting that the pumps and motors aren’t cheap I decided it wasn’t worth the risk of ending up with a motor pump combo that required too much power. One way 12v RO units save on power is by reusing the reject water which is already under pressure this makes the system more efficient but it increases complexity.

If you can use engine power or even AC this may well be the worth investigating as most if not all the parts are of the shelf. Someone has taken the thinking even further and demonstrated how to use the pressure pump from a High pressure washer. Power is the problem and has meant the owner upgrading the alternator to recharge the house batteries quickly and having to add a big enough inverter but it shows how simply these units can be.

For free taster outline plans for a 120v or engine driven water-maker look here for lots of pics and advice.

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Which Water Maker ?

A water maker or RO (Reverse Osmosis) unit makes use of a high pressure pump to force sea water through a membrane. Water that passes through the membrane is known as “product” the rejected water in brine. Its as simple as that. With high pressures does mean that the units need to be well made included all hoses, connections and the canister that houses the membrane.

The chief problem on a boat is how to drive the pump efficiently.

The most efficient way to do it is to use a flywheel off the engine, this does bring great output without the need for a 12v/115V/230V motor. But it does mean if the engine goes down, so does your water maker. It also means putting hours onto your engine when you could be sailing, so it can add to servicing costs. If you have an engine it makes most sense to start with this option.

Pelican only has two outboards so clearly this isn’t an option.

Next up is to use an electric motor to drive the pump. Its possible to drive the pump with 115V or even 230V clearly you’ll know if that an option for your yacht. This most likely means you already have generator or are happy taking power out of the batteries and converting it via an inverter. Not terribly efficient but 115V and 230V pumps are easier and cheaper to come by than 12V, they also tend to be Much more powerful so you generate more product water quicker. I have seen a semi diy 115V RO unit for sale and it was certainly a lot cheaper than a 12v version when you took into account product output but you have to have the power generating capability.

ECH2OTec Waters is a good place to the different options: engine, 12v, 115v or 230v I decided that 12V was right for me. I don’t have an engine capable of driving a pump, I don’t want the extra weight or hassle of running a generator and felt that the inverter route meant relying on more electronics and battery capacity (i.e. A bigger amp draw) than I would like to. Another reason was that Id rather invest more in 12v i.e build a bigger battery bank and add more solar which will both contribute to the power generating and storage capacity of the boat.

As with everything I had to find the right price/output/power consumption for me. There are some highly efficient 12V RO units on the market. But they come at a price. Schenker watermakers claim to be able to produce 30lt’s of water at 12v needing only 9 amps but they are expensive. Kataydn’s Powersurvivor 80E draws similar power (8 amps) but only manages 12.9lts of water during the hour its running but its cheaper.

You also need to consider how often you will need to run the unit. The membranes need to be used regularly so if you generate a weeks worth of water in one go, you may end up preserving the unit (with a mixture of chemicals and product water to stop growth) or running it without real need just so its used. My final choice is covered in a later post.