Foto's
van de dagtank
Installing a daytank
and fuel scrubbing system May,2005
I installed the Fuel Scrubbing System with Daytank for two reasons:
1. Problems with a brand new Espar dieselheater
2. To improve the boat's safety by avoiding fuel problems.
1. In May 2004 I installed a brand new Eberspaecher (Espar) D2 Airtronic dieselheater.
I had a D3L heater before, installed in 1982, that worked fine until finally,after
intensive use, the ventilator motor gave up and other breakdowns could have
been expected. Besides that, I found that the D3L, operating without a thermostat,
was dimensioned too big for the boat.
The D2 was sold to me with a small simple in-line fuel filter and since the
D3L had also functioned with a similar filter, direct from the main fuel tank,
I installed the D2 in the same way.
After about three and a half months the D2 gave up the ghost. It wouldn't ignite
anymore. The diagnosis was a complete coaled burning chamber. Roton Industries
on Granville Island in Vancouver offered a warranty repair. The D2 functioned
again. To prevent future problems I was advised, either to modify the thermostat
or to run the heater on Kerosene.
I could not accept the proposals. Modifying the thermostat would have meant
no regulation anymore , i.e. running on high all the time only. Burning Kerosene
would have meant a separate tank with a complicate and messy refilling procedure.
The heater is now running on Racor (2 micron) prefiltered and dry fuel since
May 2005 and worked flawless until the end of September. For testing purposes
it actually ran more and longer than the beautiful summer in British Columbia
required.
I was also aware of the fact that the smaller D2 could be more sensitive to
it's environment and therefore made some changes. The main improvement was to
minimise the resistance in the exhaust system.
2. The thought about an engine that quits at a moment you need it most is a
horror vision to me. In the articles I red on this subject in most of cases
the cause was a clogged fuel filter while sailing in rough weather with a nearly
empty fuel tank. Under these circumstances , switching to a second (spare) filter
,may sound logic but how long do you think it will take this filter to be blocked
as well. If you are lucky you are still able to enter a safe harbour.
Even more articles I red on the subject fuel treatment.Translating these articles
to the fuel consumption on a Fisher 30 (maybe 200 litres per season) I came
to the conclusion that in the first place I am always using detoriated diesel
and in the second place I can forget about having a clean tank (despite biocides
etc.).
I do have a sump with a drain valve on the main tank and at every start and
end of the season I drain about a litre. Most of the times there is only a few
drops of water and some undefined flakes in the glass.
Triggered by an article on this subject by Robert Chave on the Yahoo Fisher
Group Website I started to look for a concept.
I bought a transparent 25 litres dieselfuel tank from Vetus because this tank
fits perfect beside the engine ( 55cm long, 40cm high and about 20cm deep).
The price was about 160 Euro. As I received the tank I was a little sceptic
about the fittings. Simple grommets pressed into the holes of the tank and barbed
hose connectors just pressed into these grommets. For reasons I will explain
hereafter I was not sure whether the system would build up a small pressure
in this tank and was afraid that these connectors would start to leak. The Vetus
people in Schiedam (Holland) assured me that the connections would be OK. I
took the safer way and, also because I had the possibilities, I made my own
fittings out of brass with NBR (Nitril) O-ring sealings. If you do not have
a lath or somebody who knows somebody who has a lath than you maybe better look
for a custom made nylon tank with rigid welded connections. Do not forget to
have an opening of about 5cm diameter made, which will be capped after you have
mounted the micro floatswitch into the tank. The tank was supplied with nylon
fabric belts to wall-mount the tank but I replaced them by 2 mm thick copper
strips which made the mounting easier.
I already had a new Racor 220R2 filter with a capacity of 20Gph and a 2 micron
filter element.
The next step was to find a suitable additional fuel transfer pump. Most of
the pumps I found on the internet were too big (rated around 90 Gph) . I finally
found one in the NAPA (automotive parts) U.S. catalogue in the range of abt.
30 Gph. As I wanted to order this one from NAPA Canada ,I was told that the
pump was not available in Canada but I could have the type E8153 which is a
12V continuous duty pump with 30Gph (equivalent to about 2 litres per minute)
with a max. pressure of 10-14psi ( 1bar = 14psi). The price was about C$85 and
came with 14NPT to 3/8" hose barbs.
My main concern was ,that in the system I could not mount a separate connection
on the maintank for the fuel return hose of the daytank. On the Fisher 30 you
can hardly reach the top of the tank, not to mention the attempt to mount a
fitting.
The fuel return of the daytank, with a rate of 2 litres per minutes, had to
go in addition to the already existing engine fuel return via the existing return
hose. On my boat this hose has quite an outer diameter but inside measured 1/4"
only. To be sure, I made a test and poured the content of a 2 litre cola bottle
into a 1/4" funnel. Just by gravity it passed the funnel in about 50 seconds.
I have an Isuzu 40HP 4LC1 engine and I think that the injectors are not cooled
by the diesel fuel, supplied by the fuel pump on the engine, so I could expect
that the fuel return of the engine is not that much. Albeit, I am using the
existing fuel return hose for both returns. I built a hose connector in which
the overflow of the daytank is injected in under an angle of about 30 degrees
and the engine fuel return in a straight line to prevent eventual whirls that
could obstruct the free flow of the engine return fuel. You may also use a simple
"Y" hose connector with the base of the Y pointing to the main tank.
You may think that this is a bit thinking too far but I don't have my boat next
door and, coming on board and installing new systems, it should possibly function
right away.
I do not think that under these circumstances there will be overpressure in
the daytank. With this NAPA pump the 200 litres of the maintank will pass the
Racor prefilter in about two hours time , so while underway your are continuous
cleaning your fuel. If it is true that the Racor filter also spins the water
out of the fuel it will now certainly do so with the NAPA pump going over the
capacity of the filter. The former, lower fuel flow trough the Racor filter
by the engine fuel pump may not have shown this effect.If it is also true that
the bacteria in the maintank, who live for about 6-8 weeks, will now be "stored",
dead or alive in the filter cartridge since they are about 2 microns big.
The principal of the system is shown in the attached schematic, which I think
explains itself. The two service valves are implanted for the air bleeding of
the whole system. One valve closes the overflow of the daytank to the maintank
and the other one acts as a bypass valve for the pump. I planned this bypass
valve in the system because I did not know in advance of what type the pump
finally would be. As I checked the NAPA pump, I learned that you can blow through
the pump (in flowing direction) with no 12Volts applied. Blowing in the opposite
direction you find the path blocked. With this type of pump you do not need
the bypass because you can pull the fuel out of the maintank with the priming
pump on the Racor filter, right trough the NAPA pump, until the Racor filter
is filled. If you pull the piston of this little pump (which is built in the
filter) slowly back and forth in a straight line it works fine.
You might want to have this bypass valve installed if ,the pump you are using,
goes far above the capacity of your fuel return hose. By opening the valve you
will be able to regulate the Gph actually flowing to your daytank. The rest
of the fuel than circulates in the bypass circuit.
Coming so far I thought it would be a good idea to have a vacuum meter connected
to the second output of the Racor filter so that money can be saved by changing
the cartridge of the filter when it is necessary only. I did not buy the vacuum
meter from Racor (abt. C$120) but a normal 0 to –1 bar vacuum meter from
Conrad Electronics in Europe. A hydraulic shop will have them as well and you
will pay around C$20. I used the West Marine catalogue to copy the values Racor
recomments for the cartridge exchange and marked those values with coloured
tape on the dial of the meter.
If you start the system with a new cartridge you may notice that the vacuum
meter shows a low reading. In my case –0.12 bar (abt. 1psi). This is caused
by the fact that the pump capacity is higher than the Racor capacity. If you
want to have a zero reading with a new cartridge you can adjust this by slightly
opening the pump's bypass valve or, you simply add the initial vacuum reading
to the vacuum value for cartridge replacement.
On the small system's control panel you find the components to control the fuel
transfer pump as well as the alarm circuit and the vacuum meter. Since the daytank
is mounted under the Pilothouse floor boards there must be some kind of alarm,
indicating that the daytank's fuel level sinks. All the components were obtained
from Conrad Electronics (which I think is also represented in Holland). Using
LED's in circuits now a day is simple because steady or blinking LED's are made
with built-in resistances for a voltage range from 9-15Volts.
On the panel you find two switches. One for the fuel pump control (automatic-off-manual)
and one for the alarm circuit (automatic-off-test). Normal position is both
on automatic. In this position the fuel transfer starts as you start the engine
and the alarm is ON. The position "manual" is used for the initial
filling of the daytank as well as topping of the daytank since the Espar heater
also uses fuel out of the daytank. In port, the alarm will sound about every
second or third day while using the heater.
An old rule in electronics is: the more components in a circuit , the higher
the probability of failure will be. Translated into the above it means that
the fuel transfer pump may show a failure and here I want to point out that,
with the system I still can be trapped by a clogged filter but I will still
have 6 gallons of clean and dry fuel on which I can steam 6-9 hours, time enough
to look for a safe harbour or anchorage or if the weather permits, to look after
the problem. The fuel transfer pump is a cheap off-the-shelf product and despite
the label reads "not for aviation or marine use" it will do the job
on a Fisher.
You can meet engine problems for other reasons, like belts and rawwater pumps,
but that is a matter of maintenance.
Bleeding the complete system
After the system is installed and connected to the maintank, you have to fill
the daytank. The NAPA fuel transfer pump may not run dry .
Proceed as follows:
Open the main valve on the main fuel tank, open the bleeding valve on the Racor
filter and start to pump until you see the Racor is filled. Close the vent screw
and continue to pump fuel into the Fuel pump. A few strokes more and you might
see the fuel flowing in the daytank. You may now switch the fuel transfer pump
to manual and wait till the daytank is full and the overflow to the maintank
starts.
Switch the pump off and close the overflow service valve on the daytank. If
you continue to pump the priming pump on the Racor filter you will start to
build up some pressure in the daytank, forcing the fuel to flow to the fine
filter on the engine. Therefore the output of the fine filter should be opened
by disconnecting the hose to the engine fuel pump. Reconnect this hose as soon
you see some fuel is coming out of the fine filter.
Bleeding the hose from daytank to Espar can be done in the same way by opening
the Espar fuel valve and disconnecting the fuel hose from the metering pump
on the heater and pump the fuel until here. Reconnect the hose again. Finally
close the priming pump on the Racor Filter and do not forget to open
the return valve on the daytank.
In my case the engine started
at the turn of the key, the Espar took a second cycle to start
Attached you will
find the system as a principle, the wiring diagram and some pics.
Feel free to contact
me for further questions.
I want to say thanks
to Robert Chave and Cees Roos for their inputs and advise.
Pieter van Wingerden
Seepaert
1976 F30, hull 136
Snug Cove
Bowen Island (49
23N, 123 20W)
Fuel
Transfer and daytankpanel (download Worddocument)
Schematic Fuel system
(download Worddocument}
Wiring Diagram
Control Panel (download Worddocument)
Foto's
van de dagtank