See our video at: http://www.youtube.com/watch?v=jT0p9XstVx4
4. ARTICLES OF INTEREST
- From 'Ocean Navigator' July/August 2007
Watermaker Installation and Maintenance
by Nigel Calder SEE MORE
- From 'Blue Water Sailing' June 2007
Choose Wisely a Watermaker
by Sam Mazza SEE MORE
- From http://www.cruising-newcaledonia.com
A Desalinator for your yacht -
EchoTec Watermakers Versus Sea Recovery Watermakers
- Silent and cool high pressure pump - the best built! - All ECH2OTec pumps are triplex (three cylinder) ceramic (hardest cylinder walls) plunger style pumps made of duplex stainless steel - low revolution - designed to be quiet and cool - known to be the most reliable on the market today.
- No circuit boards - vulnerable in salt water environment - failures are unsolvable
- Simplicity of entirely mechanical controls - only switches, handles and gauges
- Over engineered - truly robust components - all of highest quality
- Membrane - The most expensive, best quality
- Modular - Space efficient installation - each of the three major components (control panel, pump/motor and membrane) can be installed in separate locations - helps solve those installation surprises
- Completely Assembled - All components are delivered in a completely assembled state - need only connecting
- No Proprietary Parts - Parts and especially consumables are generally available worldwide
- Warranty - Five year limited warranty on high pressure pump
- Not temperamental or finicky
- Confidence in easy reliable operation
- Fresh pure water .... and lots of it
SWEET WATER FROM SALTWATER - The technique to make drinkable or 'sweet water' from saltwater is simply to force, under high pressure (800 TO 900 psi), large quantities of water past a special membrane. By the process of reverse osmosis (RO), which is the same phenomenon that puts oxygen into our blood from our lungs, clear drinking water emerges on the other side of the membrane.
TWO TYPES OF WATERMAKER - FOR SMALLER DESALINATION SYSTEMS
Conventional systems, like ECHOTec, that use relatively big pumps and motors - requiring lots of power - similar to large desalination plants - weigh 100 to 150 lbs. (45 to 70 kg.)
'Energy Recovery' systems - use smaller plastic pumps - derived from a survival device - systems weigh 25 to 75 lbs. (10 to 35 kg.)
PUMPS - Pumps are the weakest link - suffer from over-working - excess load for size of pump - challenged pumps are hot and/or noisy. Plastic pumps are not designed for 800 to 900 PSI.
PRESSURE - Inconsistent or fluctuating pressure, especially from pulsating pumps, reduces the life of the membrane
MOTORS - Big, cool and quiet solves all issues.
LEAKAGE - Fittings and connections must be suited to the high pressure requirements. Dripping or, worse, spraying salt water causes enough problems...... dangerous if near electrics.
CIRCUIT BOARDS - Electronic circuit boards - 'Black Boxes' - and their anciliary mechanisms designed to achieve 'automatic' controls are added complexity - additional vulnerability to failure. Making water is not much more difficult than filling your tanks with a hose: switch the water on, run it for a bit, taste it, then when it tastes OK switch the flow into the tank. The backflush is simpler: just a matter of switching a 'Y' diverter to re-direct tank water to flush/clean the membrane/filter. ECH2O Tec's YACHT SERIES watermakers do not incorporate any such automatic controls to handle those simple procedures. Sailors tend to be 'around' when making water. The process is too easily monitored and managed by a human .... afterall .... only filling a tank. The sounds of saltwater splashing overboard, a starved pump, overflowing tank or lack of product flow are always self evident. The electronic minding of circuit boards and their ancilliary 'automatic' devices are not necessary and, most importantly, not worth their increased risk of failure.
MEMBRANES - Clogging of membrane caused by low flow rate of water because: 1) water impurities become too dense and 2) missing the scrubbing action of high volume water flow. An ECHOTec membrane should last 5 to 7 years of heavy usage. A membrane on a 'power recovery' system might not have half that life and with much less usage.
AIR - Only the 'energy recovery' systems suffer from build-up of bubbles causing air 'shock absorbers' in the chamber that prevent achieving proper pressure. Conventional systems all easily flush air bubbles right through.
The ECHOTec systems are engineered specifically to address all these issues - resulting in cool and quiet systems that simply 'just work'.
SAMPLE HIGH PRESSURE PUMPS
Made of duplex stainless steel alloy
Triplex/three cylinder - plunger style
Ceramic lined cylinders
.... designed to run silently and always cool - known to be the most reliable on the market today. The following selection is a sample of our eleven different models - note the weight - these are substantial units:
DC - 12 Volt - Powered from Batteries
ECH2OTec 260-DML DC Pump and Motor - weighs 47 lbs. (21 kg.)
ECH2OTec 500-BML Belt Drive Pump with electro Magnetic Clutch - weighs 24 lbs. (11 kg.)
AC - 115 or 230 Volt - Powered by Generator or Inverter
ECH2OTec 500-AML AC Pump and Motor - weighs 66 lbs. (30 kg)
WATERMAKER INSTALLATION AND MAINTENANCE
On our first boat, on which we cruised around the Caribbean for 15 years and raised our children, I installed a noisy fresh water pump under the saloon sole where it could be clearly heard all over the boat whenever it was running. We were effectively able to enforce water discipline. To this day, all members of the family never leave a faucet running!
We had other water conservation measures, which some guests found to be rather repulsive (notably using the dishwater until it was pretty disgusting and obliging anyone who took a shower to tromp up and down on the laundry.) We had the decks organized such that in a squall we could flush them and then divert the rainwater to the water tanks. We never came close to running out of water, but we had to engage in active water management.
The combination of a near-silent water pump and the watermaker on the last boat encouraged a certain degree of reckless water use. With the family, old habits die hard, but guests are another matter. They'll wallow in the shower for extended periods, and run the faucet while brushing their teeth or washing a teacup. I find it hard to take (and to keep my mouth shut) but it's really not a problem. It's all part and parcel of cruising lifestyle that has changed dramatically over the past 20 years.
Installing a watermaker
Watermakers can be bought as an integrated unit mounted on a common base plate (a "compact" unit) or as component parts, which are mounted individually in the boat (a "modular" unit). There is generally little difference in the purchase price, although there will often be a significant difference in the installation cost because of the added work required by the modular units. The choice of which to use will be driven by the available spaces on the boat, bearing in mind:
The raw water intake must be as low in the boat as possible (in order to ensure that the system receives a constant supply of water with no air entering the feed line). It must be located well away from toilet discharges, and sink, shower and bilge pump drains. Flat hull inlets should be avoided because they can cause a vacuum; a forward facing scoop is recommended. The through-hull inlet should be dedicated to the watermaker alone to avoid the risk of air entering from another system, and to ensure adequate flow to the watermaker.
Hose runs should be kept as short as possible, with as few restrictions (e.g. bends) as possible, in order to minimize friction in the system. This is especially important on the low-energy systems, where every extra foot of hose or additional bend absorbs pump energy and lowers performance.
It is a good idea to place the through-hull for the brine discharge above the waterline so that the discharge can be monitored
All components, especially filters, need to be readily accessible.
Some salt water will inevitably be lost when changing filters so the filter housings need to be placed where the water will not drip on sensitive equipment.
The high-pressure circuits may develop a drip.
All connections need to be located where they also will not drip on sensitive equipment (at any angle of heel).
Traditional watermakers are noisier than the low energy models: they need to be located where they will not disturb the crew.
Following installation, it is an excellent idea to log as much benchmark data on the performance of the unit as can be measured with the available instrumentation. This data will provide invaluable reference points for future monitoring and troubleshooting (in particular, giving early warning of filter and membrane fouling). It should include such things as:
The source water (sea water) temperature.
The feed water pressure (if there is a booster pump) upstream of the filters (on the inlet side of the main pump).
The operating pressure on the system (at the membrane housing).
The product water flow rate (if no gauge is available, this can be measured by diverting the flow to a bucket and timing how long it takes to collect a measured amount).
The salinity of the product water (if there is a salinity meter).
The brine flow rate (this can be measured by holding a bucket below the discharge through-hull and timing how long it takes to collect a measured amount).
The amp draw on a DC system.
Filter and membrane care are the two principal maintenance issues with watermakers. In addition, most high-pressure pumps, have an oil-filled sump that needs checking from time to time.
The addition of some kind of monitoring device (such as a pressure gauge on the suction side of the main pump) that will warn when filters start to plug is recommended; more sophisticated watermakers also have an automatic shut-down circuit that will not allow the watermaker to be run with plugged filters.
Raw water strainers are cleaned as with an engine raw water strainer - most have a removable basket that is washed out with seawater.
Additional filtration generally consists of some kind of removable pleated filter. These can often be cleaned by careful flushing of the filter surface. Each time it is hosed off will yield approximately an additional 50-percent life expectancy (e.g., if the new filter runs 100 hours, and after the second another 25 hours, etc.). At the first sign of damage, the filter must be discarded (some manufacturers recommend to clean no more than once and then discard).
Depending on how the watermaker is used, membrane care can be the major part of the needed maintenance. The extent of the work involved varies markedly from unit to unit, principally as a function of the quality of the source water filtration, regularity of use, whether or not there is an automatic flushing circuit, and the extent to which membrane maintenance is rendered unnecessary by a Z-Guard or Z-Brane unit.
Flushing a membrane
As noted previously, if a membrane is left unused for more than a week, it will be susceptible to bacterial fouling. The best way to minimize watermaker maintenance is to use it often: in other words, do not fill the tanks and then shut the watermaker down for two weeks; instead, top off the tanks at least every three days. If the unit is to be left unused for more than a week without Z-Brane protection, it either needs to be put into storage mode or else flushed with fresh water at least once a week.
Note that long distance passage-makers confronted with an approaching storm may find it advantageous to top off the tanks before the storm hits. This way there will be plenty of water on board, and the system will not need to be run, flushed or maintained in any way for several days.
Typically, the water used for flushing (somewhere between five and seven gallons) is drawn from the boat's water tanks. However, traces of chlorine will do permanent damage to membranes. For this reason, some installations include a separate tank into which product water is diverted and held for flushing purposes, while others include an activated charcoal filter between the water tanks and the flushing circuit. The charcoal filter removes any trace of chlorine. Note that once wetted, charcoal filters only last about six months.
Bare-bones systems have to be flushed manually, which is one by switching to a couple of valves on the inlet and discharge sides of the watermaker and then turning it on. Sophisticated systems have automatic flushing controls powering solenoid-operated valves. The flush interval can be set by the user. This enables a watermaker to be left idle for some time without the need to pickle the membrane (so long as the unit does not run out of flushing water).
On some units, the flushing water also passes through the feed pump, while on others it does not, which leaves salt water standing in the pump. If the pump is made of plastic (e.g. the Shurflo pump used by Spectra and others) this is not a problem, but if it is made of stainless steel it may lead to corrosion.
Pickling a membrane
Special biocides are used for pickling a membrane. These are mixed with product water and then pumped through the system, leaving the membrane cylinder full of the biocide solution. When it comes time to put the unit back in service, the biocide is flushed out by running the unit in an unpressurized state (to achieve maximum flow through it, with no product water production) for some time (generally 15 to 20 minutes) before restoring pressure and production. The initial product water will still be high in dissolved solids, and so must be discharged overboard via a bypass line (this is the case any time a watermaker is first stared). On cheaper units, this is done manually; on more sophisticated units, a salinity meter controls an automated bypass circuit.
Note that some watermakers (notably Spectra) include parts that will be degraded by some pickling agents. It is essential to use only the pickling agent recommended by the manufacturer.
Winterizing takes the form of pickling the membrane (it must never be left dry), draining the filter and the rest of the plumbing (filters should not be left wet) and, in some cases, adding potable antifreeze (propylene glycol, such as sold for winterizing RVs and caravans) to the high-pressure pump (the low-energy pumps, in particular, can trap water that is hard to drain out; this can crack the pump in a hard freeze). Spectra also recommends pickling the membrane with propylene glycol, and in fact suggests this for pickling in general, because "this seems to do less damage to the membranes than other storage compounds".
In general, it is best to backflush the system every week, if this can be done, rather than pickle it during a relatively short-term lay-up.
Cleaning a membrane
Over time, a membrane will inevitably become fouled. A watermaker will exhibit higher than normal pressures and lower than normal product water flow rates. However, before assuming the membrane is to blame, check the feed salinity, feed temperature, operating pressures and filters. Also, check the operating voltage (DC or AC) at the pump under load. DC systems, in particular, will be significantly affected by low voltage.
Membranes need cleaning on average once every two years (membrane life on average, is five years). There are two types of membrane cleaner - alkali and acid. The alkali is most effective on biofouling and is generally used first (some firms recommend using the acid first). The acid is effective on mineral fouling (e.g., calcium), but is generally only used if the alkali fails to restore product water flow rates.
To clean a membrane, it is first flushed with clean water and then the alkali solution is mixed with the clean water in a bucket (preferably hot water to improve the performance of cleaning agents). The unit is run for an hour or so to circulate the solution through the membrane, then allowed to rest for an hour or so, and run again for 15 minutes or so.
If performance is still poor, the same procedure is repeated with the acid cleaning solution. Cleaning membranes is hard on them and something of a crapshoot. It should only be done when other measures do not restore output or operating pressures.
When operated with properly filtered source water, traditional watermaker high-pressure pumps will need the valves and seals replaced approximately every 2,000 hours of use. The manufacturers provide rebuild kits and instructions. Booster pumps and the feed pumps on the low-energy systems will also need an overhaul at similar intervals of use. Additionally, those pumps that have an oil-filled crankcase need an oil change every 500 hours.
Almost all large-capacity watermakers require an AC power source (i.e., an onboard AC generator). For lower capacities, AC, DC and engine driven units can all be used.
AC watermakers: On a boat with a continuously operating AC generator, a relatively small AC watermaker can run long enough hours to meet the overall load on the generator demand This helps to keep the overall load on the generator down, minimizing the size of generator needed, and the size and weight of the watermaker. When a generator is only run intermittently, the watermaker needs to have the capacity to meet the demand in the restricted running hours. This may result in a large watermaker that then requires a larger generator to run it. Longer generator running hours may have to be accepted in order to downsize the watermaker and generator. Alternatively, it may be possible to employ load-sharing technology to run a larger watermaker from a relatively small generator by managing the other AC loads on board.
DC watermakers: DC watermakers are run off the batteries. Typically, the demands of the watermaker are low enough, and the capacity of the battery bank large enough, to be able to run a relatively small watermaker long enough hours to meet the boat's needs. The batteries are then recharged during normal charging periods. (Note that most DC watermakers will have somewhat higher output when batteries are being charged because of the higher voltage on the DC system: it often pays to include battery charging periods in the watermaker run time). The net result is a relatively small and lightweight installation that can meet a substantial water need. The precondition is a DC system that has capacity to handle the demands of the watermaker.
Engine-driven watermakers: Although watermaker pumps can be driven off a boat's main propulsion engine, this is not generally recommended. The variable engine speeds when the boat is underway may cause problems, and in any case most times you don't want to have to run the main engine at anchor to make water. If the boat has an AC or DC generator (both of which typically run at fairly constant speeds), it may be possible to configure the system to directly drive the watermaker pump. However, it generally makes just as much sense, and is a more versatile installation, to use an AC- or DC-powered watermaker. In any event, if an engine-driven watermaker is used, it needs to be sized to provide the necessary output during normal engine-running hours.
The Zeta Guard (Z-Guard) Protection System from Spectra consists of a filter housing containing an electrode that generates a powerful electrostatic field. It is placed in series with the raw water supply to a watermaker (or any other device using raw water). The theory is that the Z-Guard puts a positive charge on any particles (mineral or bacterial) in the source water. This positive charge is said to keep the particles from binding together, and from sticking to surfaces in the system, including the membrane. In this way, biofouling and scale formation is minimized.
Spectra claims that a Z-Guard (or Z-Brane, an adaptation of the Z-Guard specifically designed for membrane protection) eliminates the need for pickling watermakers when they are not in use, but others in the industry believe that the effect of the electrostatic field is short lived, after which the water reverts to its natural state, rendering the system ineffective. The Z-Guard and Z-Brane units run on 12 volts, pulling 150 mA (3.6 Ah over 24 hours).
A mid-Atlantic problem
On our recent trans-Atlantic passage (High pressure makes for a smooth passage," Nov./Dec. 2006, Issue No. 158), the hose from the feed pump to our watermaker split at the hose nipple (as a result of a combination of using the wrong hose, and then not securing it adequately, which allowed the hose to flex under pressure from the feed pump). Salt water sprayed all over the engine room, including the fresh water pump, which destroyed the high-pressure shut-down circuit on the pump. The fresh water pump went into full continuous operation, drove the pressure on the fresh water system above the setting for the pressure relief valve on the hot water tank, and dumped all the fresh water from the tank in service into the bilges.
Unfortunately, we had previously drained the other water tank dry, so now, mid-Atlantic we had no fresh water on the boat. We were able to re-supply from the watermaker, but had this failed we would have had a problem we would never have had on our previous boats precisely because we had a watermaker on board!
I learned a couple of lessons from this. The first is to never run one water tank dry before switching to the next, but rather to run one down half way and then switch, and to then refill from the watermaker once the second is half empty. This way, there will always be an emergency supply of fresh water on board. The second is that even with a watermaker, it's important to keep track of water usage. Our next boat will have some kind of an alarm that goes off if the fresh water pump runs for more than a certain length of time.
Troubleshooting a watermaker
System will not start: The problem is probably electrical. Check for voltage at the motor. If not present, check all fuses and breakers, and any shutdown circuits (the unit may have shut down because of high or low pressure). If there is a voltage at the motor, check the motor itself.
System starts but shuts down after a while: The high- or low-pressure protection devices are sensing plugged filters or abnormally high operating pressures.
Pump is operating but there is no product water: Check the high-pressure gauge to ensure that the system is operating at the required pressure. Make sure the suction side through-hull is open, all valves are in the correct position (you may be sucking from a flushing intake or discharging the product water overboard), and the pressure relief valve is not open.
Reduced product water: A traditional watermaker operating in cold water will experience a substantial drop in its product water output. Otherwise, suspect a fouled membrane (the membrane housing pressure will be unusually high on a low-energy system, but may not be on a traditional unit; the amp draw will be high on the low-energy system); on a low-energy system plugged filters may also cause a reduce output (check the inlet pressure/vacuum to the main pump to see if it is low), as will low voltage at the pump when operating. There may be leaks in the high-pressure hoses. If none of these are the case, the high-pressure pump cylinders may be leaking past the pistons. In all such cases, the amp draw on a low-energy system will be lower than normal.
Normal water production but with high pressure: The seawater is colder than normal and/or the membrane is fouled.
Normal water production but with low pressure: The seawater is warmer than normal or the salinity is lower than normal.
Water production is high but poor quality: There is a membrane failure or an O-ring failure in the membrane housing.
Low-energy watermaker exhibits uneven pressure and flow readings: One of the seals in the shuttle valve, on the piston rod or in the cylinders, is leaking by, or one of the cylinders is scored and leaking by.
Low-energy pump locks up: The shuttle valve is broken. The pump may, in fact, run when unpressurized, but lock up under pressure. On some of the earlier Spectra models it can be repaired by drilling a hole through the shuttle valve and screwing the pieces back together!
Article from BLUE WATER SAILING - June 2007 issue
....the response from Spectra's President in the August issue of Bluewater Sailing magazine - 'Letters to the Editor'
Watermaker solutions for cruisers
A Desalinator for your yacht -
EchoTec Watermakers Versus Sea Recovery Watermakers
A reliable desalinator can make your cruising in the South Pacific much easier and also much safer.
Do you need a water maker aboard your cruising yacht?
Your health is THE most important thing you need to worry about when sailing far from civilized medical services. Drinking contaminated water is one of the most common ways cruising sailors get sick - and believe me, you can get extremely sick from water that is contaminated with a cocktail of viruses, bacteria, protozoa, microscopic nematodes, yeasts and fungi. You can never be sure if shore water is safe to drink - tap water might be fine for locals who have drunk the water since they were a baby, but that doesn't mean your system is ready for it.
As a research scientist on environmental problems in the Pacific Islands I learned all about island water supplies a very long time ago and the systems have, in many areas, degraded even more.
It's not just the biological contaminants you have to worry about either. My wife and I once got lead poisoning in PNG from drinking rain water from a catchment tank that had, years before, been "sealed" by painting the interior with a red lead paint. When we started cruising 30 years ago we relied on catching rainwater and purification filters - but in PNG there was a 4 month drought and the lead got through our filtration system. I nearly died from acute lead poisoning
How much water does a cruising yacht use?
My wife and I use between 20 and 30 liters of water a day for showers, washing dishes, cleaning, and rinsing. We use another 9 liters of water a day for drinking and cooking. The Moira's tanks hold about 400 liters of water which means that we would run out of water in 10 days - although we can stretch it to two weeks if we are careful. We use Whale tip-toe foot pumps in the shower and galley to conserve water and although we have pressure water aboard we rarely use it.
Even during the rainy season in the tropics we used to have to find shore water somewhere about once a week or carry drums ashore to fill. This is a royal pain after a few years of continuous cruising and can be a serious problem if there isn't a handy source of potable water around. I guess in a pinch we could have survived on just 8 or 9 liters of fresh water a day but who wants to?
Which is the best desalinator for a cruising yacht?
If you are thinking of buying a watermaker our recommendation is to get an ECHO Tec unit. ECHO Tec watermakers are designed and built for cruising yachts. ECHO Tec is a yacht-friendly company based in Trinidad. Their desalinators cost half as much as the big name Superyacht brands.
I bought the ECHO Tec 500-BML-1 unit with a low pressure gauge, maintenance kit, extended maintenance kit, boost pump and dual prefilters and had it shipped to New Caledonia for half the price that I paid for a Sea Recovery Ultra Whisper a couple of years ago (more about that mistake later).
We installed our ECHO Tec watermaker ourselves aboard our 44' cutter Moira. It was easy to set up and when we turned it on, I was (and am still) astonished by the stream of water it puts out. It is "rated" to put out 20 Gallons (76Lt) per hour but in fact it gushes out 31 gallons (120 liters) an hour. Every other watermaker I have heard about invariably puts out less than factory specs - especially after it has been in use for a long time.
The ECHO Tec desalinator has been easy to maintain. In fact, we've done nothing at all but use it and change the prefilters since we installed it six months ago. We use it every day and it has kept our tanks brim full since day one of operation. With our normal water use, we only need to run it from 20 to 30 minutes every day. We've even started using our pressure water system for showers!
About Yacht Watermakers
Desalination of seawater using reverse osmosis membranes became a reality in 1959 when a team of researchers at UCLA made a breakthrough in cellulose acetate polymer membranes. The first commercial reverse osmosis plant began operation in 1965 in the California town of Coalinga. By the mid 1970's, when Freddy and I began our cruise of the Pacific, boat sized desalination units were just appearing on the market. But they were a nightmare of plumbing and power problems - after all, in order to desalinate seawater you need to create a constant flow of seawater through the membrane element at between 40–70 bar (600–1000 psi).
The Power Survivor Watermaker
In the late 1980's a small company in Canada began making a little 12 volt desalinator called the Power Survivor. It was the first desalinator I had seen that was engineered as a single, integrated unit to desalinate water. It only made about 4 liters an hour but that was enough to keep us in drinking water. I bought one immediately and used it for more than a decade, changing the membrane unit every 2 or 3 years (we found that staying in a marina and pickling the membrane invariably shortened the life of the membrane).
Unfortunately, Pur bought the Power Survivor technology. They did a re-design which looked good on paper. I bought one and the new "updated" unit worked about 2 months before it began to have serious problems. We found the Australian service center for Pur to be hopeless. We continued using the old Power Survivor while trying in vain to get the new one repaired.
Pur sold the technology to the Katadyn water purification company. Katadyn service and support was so poor we decided the era of the wonderful Power Survivor had ended - at least for us. Anyway it would be nice to have more output and after our experiences with the Pur technology and Katadyn's "service" it was not going to be one of their larger units.
Sea Recovery Watermaker Problems
I did a great deal of research - but alas not enough. I missed a 2001 post in www.sailnet.com that read "Avoid "SEA RECOVERY" like the plague. Send me an email if you want a list of problems - too long to list on BB." Oh how I wish I had seen that posting before I dropped AUD$12,000 on a Sea Recovery Ultra Whisper modular unit.
The dealer in Australia had just switched to Sea Recovery after having a series of problems with Spectra watermakers. His showroom model looked fantastic so we ordered one. When we started to install it our problems began. The installation and service book that came with the unit was the most confusing document I have seen in a long time - for example, the high pressure pump described in the handbook wasn't even the correct model. Eventually, after nearly 10 days, and with the able assistance of the dealer in Australia, we got it set up and turned it on.
The Sea Recovery Whisper 400 is a 12 volt "energy saving" desalinator. To paraphrase that 2001 post I mentioned earlier, Avoid energy saving 12 volt desalinators like the plague.
It worked fine when we first ran it, although it did not put out as much as it was rated for. So we sailed off to New Caledonia and Vanuatu with our high tec water maker. After three months of cruising the output gradually fell off to a pathetic trickle. Mysteriously sometimes it would put out almost half of it's rated capacity and then the next day, for no obvious reason, it trickled out less than our old power survivor.
The unit was still under warranty but we in New Caledonia on our way to Vanuatu so we could not call the Aussie dealer and tell him to come by for a look. The Sea Recovery Dealer in New Caledonia - Alto marine - told us that since they didn't sell the unit they were not obliged to help us get it fixed. I sent emails to the Australian dealer who sold it to us with copies to Sea Recovery in California asking what they thought was wrong. I finally got a reply from Sea Recovery and they diagnosed the problem as a faulty feed pressure pump head. They sent a replacement under warranty (I had to return the faulty one).
That didn't fix it. So they decided the seals in the Energy Transfer Device needed to be replaced.
When the new Oring seals and valve kit arrived, Sea Recovery had valued it for Customs at US$410 - and I had to pay 40% customs tax on that which was, I thought, pretty expensive for a package of seals. I managed to get the new seals in place without too much trouble but as I replaced them I began to realize there was a major flaw in the concept of "energy saving" devices that relied on two double-ended pistons moving back and forth inside a cylinder with high pressure sea water. There are 11 sliding seals and 26 o-rings in the Sea Recovery Energy Transfer Device. The sliding seals are a special plastic but they wear as they slide back and forth in the stainless housing trying to build up the required 600psi to squeeze fresh water through the reverse osmosis membrane. At US$410 a pop plus a day's effort to disconnect, dismount, take apart, reassemble, remount, reconnect the unit (which is really heavy, by the way) this is a major problem if it needed to be done once a year. Replacing them every couple of months would be- and turned out to be - a nightmare.
Sea recovery high pressure piston at 120 days of use.
The new seals began to wear out after another 60 days - but meanwhile another problem popped up. At the ends of the two lower cylinder housings for the Sea Recovery Energy Transfer Device there are two stainless plugs. They serve no obvious purpose. One of them developed a pin-hole leak through the threads. This sprayed atomized sea water throughout our engine room.
Out comes the Energy Transfer Device, take it apart, remove the leaking plug, and screw it back with the very hardest high pressure thread compound we could find. I noted that the plug was not "pipe thread" that could be expected to seal OK under pressure and there were very few threads to hold back the pressurized sea water and the plug wasn't even a very good fit. Such a tiny bit of inconsiderate engineering for such a complex and expensive bit of gear. Anyway, got it back in place, waited 48hrs to be sure the thread compound was fully hardened, fired it up and hey - it leaked again. I repeated the process with another brand of high pressure sealant and this time it sealed OK. in another two weeks the plug on the other end let go. I suppose I should have anticipated that. Disconnect (that means removing 4 high pressure connectors and sponging up the sea water that goes everywhere), Dismount (remove the 4 mounting bolts, heft it down and out of the engine room), remove the plug, redo the bedding compound, let it sit for 48 hrs to assure complete cure, remount, reconnect.
The mini-inconsiderate-engineering-stupidities of Sea Recovery engineering extend even further. On a weekly basis we changed our two prefilters. This simple changing of two filter cartridges was a major effort. The filter housings have a raised ridge with rounded plastic tabs on them so you can unscrew them. Good luck. Their engineers somehow managed to design and build the filter housings so they screw in and jam. Getting them to unscrew was a violent struggle. I bought steel strap and rubber strap and jawed filter removers. Finally I resorted to using a big screwdriver placed against the ribbed part of the housing and tapping it loose with a hammer.
After a year (and another set of seals and orings) we again had sea water atomizing in the engine room. This time it was a pinhole leak in one of the very small elbows on the Energy Transfer Device. Before trying to repair it, I needed some replacements. In December I sent an email to the woman in charge of parts for Sea Recovery asking for replacements. No reply. However it was the cyclone season in New Caledonia and we were in the marina - the desalinator was in storage mode. Sometime in February I realized I had not had a reply so I sent another email. No reply. In June, when we were ready to fire up the desalinator again I wrote emails to everyone in Sea Recovery plus the Australian dealer explaining that my $12,000 desalinator was sitting idyll because of a little elbow fitting. I had tried to find a replacement myself without success. The shot-gun spread of emails found its mark and in another 30 days a package arrived with 4 replacement elbows. Right, by now it was a routine, disconnect, dismount, remove the faulty elbow. Oops. When trying to take the elbow out it broke off flush with the Sea Recovery Energy Transfer Device unit. The reason it broke off was because the elbow was chrome plated brass screwed into the stainless housing. Electrolysis had turned it into a sponge. Next, get a screw extractor and try to remove the rotten brass without hurting the threads in the housing itself. This only took a few hours. When I opened the bag with the replacement fittings I was astounded, really amazed, to find that the replacement elbows were not only salvaged from an old unit but whoever took them out damaged the threads so they were useless! And they were also plated brass. I used the least damaged one to replace the one that had leaked and sent off some blistering emails to Sea Recovery about sending crap replacements of such a cheap but vital part.
And so the story goes. I finally got replacement fittings and went through the process of replacing them (yes, the others also broke off when I tried to remove them). At the end of the cruising season my Sea Recovery watermaker was barely trickling out water again. We also had to replace our steering cables because of their repeated exposure to the salt water from the desalinator.
I hated to admit it but I had thrown away $12,000 when I bought the Sea Recovery watermaker. I doubted it would ever work properly. All the safety and automated product water testing features were screwing up. The electric relays for the feed motor had blown and were replaced. The membrane salt detection system was cleaned twice (not easy either) and I finally simply disconnected it. I started looking for a replacement desalinator.
ECHOTec Watermakers comes to the Rescue
ECHOTec had very good online reviews with satisfied customers. The more I saw, the better I liked their unit. I also liked their reasonable prices. I ordered one and ECHOTec shipped to me in Noumea. I unpacked the crate on a Tuesday. I got the model that mounts on the front of the engine and is belt driven. I had to get a new pulley turned to fit on the motor and that took a couple of days - during which time I installed the rest of the modules. Unlike the Sea Recovery experience, installing the ECHOTec was a breeze. It actually took me longer to remove the Sea Recovery modules than it did to install the ECHOTec. The ECHOTec uses "standard" fittings, not special made-to-order-impossible-to-find parts. I was ecstatic that the prefilter housings were clear (so I could see when the filter needed changing) and Sooooo easy to change the filter. Silly as it sounds that little comparison between the ECHOTec and the Sea Recovery watermaker was enough to really delight me. When the engine pulley was ready I bolted it on, connected it all up and fired up the diesel. WOW. Product water came out in a really healthy stream and within 30 seconds tasted perfect.
After six months of every day use I have come to love my ECHOTec watermaker. Simple, efficient, powerful, perfect. I especially like the fact that when my diesel engine spins that high pressure pump the pressure goes right up to 800psi and product water comes gushing out. Every time I start it up I remember watching the high pressure gauge of the "energy saving" Sea Recovery unit struggling to make 500 psi. Don't let anyone sell you on the idea of an "energy saving" 12 volt system. We had to run our diesel to make enough juice to operate the watermaker anyway so why worry about a big, expensive, complex energy saving unit when you are going to run the engine anyway?
We now enjoy more water than we need and a trouble free system that is a pleasure to maintain.