Navman DIESEL MULTI FLOW SENSORS User Manual

DIESEL FUEL

F L O W S E N S O R S

Installation and

Operation Manual

English .................... 3

Español ................. 38

Português ............. 73

www.navman.com

NAV MAN

FCC Statement

Note: This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a normal installation. This equipment
generates, uses and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If
this equipment does cause harmful interference to radio or television reception, which can
be determined by turning the equipment off and on, the user is encouraged to try to correct
the interference by one or more of the following measures:

Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an output on a circuit different from that to which the
receiver is connected.
Consult the dealer or an experienced technician for help.
A shielded cable must be used when connecting a peripheral to the serial ports.

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Diesel fuel fl ow sensor kit Installation and Operation Manual

Contents

Contents ................................................................................................. 3

Important ................................................................................................ 5

1 Introduction .................................................................................. 6

1-1 Diesel fuel flow sensor features ................................................. 6

1-2 A typical system ........................................................................... 7

A diesel flow sensor .....................................................................................7

1-3 The bypass valve ..........................................................................7

2 Understanding boat performance data ...................................... 8

Boats ............................................................................................................8

Fuel Consumption ........................................................................................8

Engine RPM .................................................................................................8

Boat Speed ..................................................................................................8

3 Plotting a fuel consumption curve ............................................. 9

3-1 Fuel consumption table ............................................................. 12

Notes on filling out this table ......................................................................12

3-2 Understanding the fuel consumption curve ............................ 14

A typical fuel consumption curve ................................................................14

Understanding your fuel consumption curve ..............................................14

Note on fuel usage .....................................................................................14

4 Measuring your propeller’s performance ................................ 15

Propeller size .............................................................................................15

Slip factor ...................................................................................................15

Calculating the slip factor ...........................................................................15

Understanding your slip factor ...................................................................16

5 Measuring engine performance ................................................ 17

5-1 Engine power and propeller curves ......................................... 17

The theoretical propeller load curve ...........................................................18

5-2 Specific fuel consumption curve .............................................. 19

6 Diesel fuel flow sensor hardware ............................................. 20

6-1 What comes with your diesel fuel flow sensor kit .................. 20

6-2 Options and accessories ........................................................... 20

Filtering the fuel ..........................................................................................20

6-3 Sensor fittings ............................................................................ 21

Diesel fuel flow sensor kit Installation and Operation Manual

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7 Installing the diesel flow sensor kit .......................................... 22

Installation sequence .................................................................................22

7-1 Twin engine installations ........................................................... 22

7-2 Notes on pipes, fittings and installation .................................. 23

7-2-1 Pipe ..........................................................................................................23

7-2-2 Flare Nuts ..................................................................................................23

7-2-3 Flexible Hoses. ..........................................................................................23

7-2-5 Threadseal tape or paste ............................................................................23

7-3 Planning where the parts of the kit will be fitted ..................... 25

7-3-1 Overview ....................................................................................................25

7-3-2 Mounting a sensor ......................................................................................25

7-3-3 Locating the sensors in the fuel lines .........................................................26

Locating the supply sensor ........................................................................26

Locating the return sensor .........................................................................26

Sensor mounting positions .........................................................................26

7-4 Installing the temporary straight through pipes ..................... 28

7-4-1 Installing a through pipe with flare joints into a copper pipe run ................29

7-5 Test running and installing the sensors ................................. 31

7-6 Installing the tachometer pickup .............................................. 33

Locating the tachometer pickup .................................................................33

Installing the tachometer pickup .................................................................34

7-7 Installing the cables ................................................................... 35

7-7-1 Link and tachometer cables .......................................................................35

7-7-2 Connecting to a DIESEL 3200 ...................................................................35

Appendix A Specifications ................................................................. 37

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Diesel fuel flow sensor kit Installation and Operation Manual

Important

It is the owner’s sole responsibility to install and use the instrument and its sensor(s) in a manner
that will not cause accidents, personal injury or property damage. The user of this product is
solely responsible for observing safe boating practices.

Fuel type: Navman diesel flow sensors (metal) and DIESEL 3200 instruments have been
specifically developed for use in marine applications with diesel engines and are not warranted
for any other type of application. These sensors and instruments must NOT be used with petrol
(gasoline) engines.

Fuel formulation: Every effort has been made by the manufacturer to ensure that the materials
used in the Navman fuel flow sensor(s) will operate reliably with different fuel mixtures. The
manufacturer or its distributors can not be held responsible for fuel formulation or any affect this
may have on the performance and durability of the fuel flow sensor(s).

Back pressure: A diesel fuel flow sensor will create additional back pressure in a fuel system
of an estimated 0.3” of mercury at 25 US gallons /hour (100 litres/hour) and 1.5” of mercury at
80 US gallons per hour (300 litres/hour).

It is the owners responsibility to ensure that fitting the fuel flow sensor(s) does not cause fuel
starvation which may lead to poor engine performance.

Fuel Computer: Fuel economy can alter drastically depending on the boat loading and sea
conditions. The fuel computer should not be the sole source of information concerning available
fuel onboard and the electronic information should be supplemented by visual or other checks
of the fuel load. This is necessary due to possible operator induced errors such as forgetting to
reset the fuel used when filling the tank, running the engine with the fuel computer not switched
on or other operator controlled actions that may render the device inaccurate. Always ensure
that adequate fuel is carried onboard for the intended trip plus a reserve to allow for unforeseen
circumstances.

Specific requirements: Your boat’s fuel installation boat might be subject to specific requirements
(such as USCG, NMMA and ABYC guidelines or local laws), particularly if the boat is licensed,
surveyed, charted or inspected. It is the owner’s sole responsibility to install and use the instrument
and its sensor(s) in compliance with these requirements.

NAVMAN NZ LIMITED DISCLAIMS ALL LIABILITY FOR ANY USE OF THIS PRODUCT IN A
WAY THAT MAY CAUSE ACCIDENTS, DAMAGE OR THAT MAY VIOLATE THE LAW.

Governing Language: This statement, any instruction manuals, user guides and other information
relating to the product (Documentation) may be translated to, or has been translated from,
another language (Translation). In the event of any conflict between any Translation of the
Documentation, the English language version of the Documentation will be the official version
of the Documentation.

This manual represents Navman’s Diesel fuel flow sensor kit as at the time of printing. Navman
NZ Limited reserves the right to make changes to specifications without notice.

Copyright © 2004 Navman NZ Limited, New Zealand. All rights reserved. Navman is a registered
trademark of Navman NZ Limited.

Diesel fuel flow sensor kit Installation and Operation Manual

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1 Introduction

The Navman diesel fuel flow sensor kit
measures the fuel consumption and RPM of
your diesel engined boat. But that is a gross
understatement of the capabilities of this
powerful diagnostic tool. This manual is written
to help you understand the many functions the
system can perform, and to help you interpret
the numbers it can provide. We also give some
basic information on some of the factors which
can influence boat performance, and what the
various readings from the sensors can reveal
about your boat. Hopefully, by understanding
more, you will no longer think of the engine as
just a noisy and expensive mystery.

In the end we should be able to help you make
your boating experience more relaxing, safer,
more economical and better informed.

This manual describes:

How to install a diesel fuel flow sensor kit
onto a diesel engine (sections 6 and 7).

How to understand and interpret the fuel
sensor readings (sections 2 and 3).

How to use the fuel flow readings to
understand and optimise your propeller
and engine performance (sections 4 and

5).

Note that this fuel flow sensor kit does not
have a display. The kit must be installed with a
Navman marine instrument to display the fuel
readings, such as the DIESEL 3200. A second
sensor kit can be fitted for twin engine boats.

It is vital to read this document and the Navman
display instrument’s installation and operation
manual before installing or using this kit.

1-1 Diesel fuel flow sensor features

A positive displacement flowmeter, with
one moving internal part - there are no
fine pointed shafts and jewelled bearings
to get worn or hammered by diesel
pulsing.

Diecast aluminium housing.
A direct flow bypass valve, to take the

sensor out of the fuel line if required.
Low pressure drop across the sensor.
Simple, in-line installation, much like a

primary fuel filter.
The inlet and outlet ports have a

commonly-available thread: a ¼ NPT
parallel female thread on sensor is used
with a ¼ NPT taper male thread on the
fitting.

No restrictions on pipe geometry on entry
or exit from sensor.

Supplied with temporary straight through
pipes to make installation safer.

Factory tested and calibrated - sensors

do not normally require calibrating again.

Each engine is fitted with two fuel flow sensors.
One sensor, in the the fuel supply line measures
flow from tank to engine. The other sensor, in
the fuel return line measures flow from the
engine back to the tank.

The flow sensor system calculates the engine
consumption from the supply and return flow
rates. It compensates for:

Reverse flow pulsing from diaphragm lift
pumps.

Different fuel temperatures in the supply
and return lines - as fuel heats up it
expands and its viscosity changes

The flow characteristics of the sensors.

The system also has a tachometer to measure
the engine RPM with digital accuracy.

The system reports the fuel flow, total fuel
consumed and engine RPM over a serial digital
information link to the Navman instrument to
display the fuel data.

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Diesel fuel flow sensor kit Installation and Operation Manual

1-2 A typical system

Other wiring and

connection to sensors on

a second engine (optional)

Primary

filter

Diesel

tank

Return fuel line

A diesel flow sensor

Bypass valve (see below)

Fuel inlet / outlet port

Display unit,
such as a
DIESEL 3200

Other connector(s)

Sensor cable

Supply

flow

sensor

Link cable

Supply fuel line

Return

flow

sensor

Tachometer cable

These parts are included
in a diesel flow sensor kit

Mounting bracket

Fuel inlet / outlet port

Diesel

engine

Tachometer

pickup

Two electrical connectors

LED, blinks when fuel is passing

(underneath)

through sensor (underneath)

1-3 The bypass valve

Each flow sensor is fitted with a bypass
valve:

Diesel fuel flow sensor kit Installation and Operation Manual

Bypass valve
Normal position, fuel

flows through sensor

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Identification band:
Blue: Supply line sensor
Red: Return line sensor

Bypass valve
Bypass position, fuel flows

directly from the sensor inlet
to the outlet and does not
pass through the sensor

- bypass the sensor if you
suspect the sensor is not
working properly

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2 Understanding boat performance data

As with all measurements, you will get no
meaningful data if you do not have accurate
instruments. Once you have accurate fuel
consumption, boat speed and engine speed
figures, then the true power of the diesel flow
sensors can be used.

Boats

All boats are different - even consecutive boats
off a production line can be quite different
in performance. So there is no real ‘generic’
data that can be applied to your particular
boat/engine/propeller combination.

Fuel Consumption

The simplest set of information you can get
from the diesel flow sensors is fuel consumption

- US Gallons per nautical mile or Litres per
mile. This figure will depend on many factors

- the condition of the hull (clean or fouled), the
loading and trim of the boat, wave and wind
conditions. Over time you will get an idea as to
how different conditions affect the performance
of your boat.

Engine RPM

Engine revolutions per minute (RPM) is the
single most important item in any instrument
package, as it is the base line against which
such things as boat speed, fuel usage, and
propeller efficiency are measured - if your base
line is inaccurate all the readings using it are
inaccurate. Accuracy is all important.

Many rev counters supplied with engines are
not very accurate, and should be recalibrated
after they have been installed in your vessel.
Navman have designed a tachometer as part
of the diesel flow kit. The tachometer measures
engine RPM digitally, with timing derived from
the highly accurate crystal running the whole
system. This digital tachometer never needs
calibrating.

Boat Speed

Check that your boat speed instrument is
reading correctly. If necessary, recalibrate
boat speed as described in the instrument’s
operation manual.

Remember that there are two distinct ways
to describe the movement of a boat - speed
through the water, and speed over the ground.
In still water with no tides or currents then
these two speeds produce the same reading;
otherwise they are quite different, and you need
to be sure you are using the correct one:

Speed through the water is usually read
from a paddle-wheel sensor. Use this
speed to check your boat’s performance
and fuel consumption.

Speed over ground is usually read from
a GPS receiver. Use this speed to work
out maximum range, fuel reserve and
time of arrival.

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Diesel fuel flow sensor kit Installation and Operation Manual

3 Plotting a fuel consumption curve

A fuel consumption curve gives a picture of how
fuel consumption varies with engine RPM, and
allows you to select an economical cruising
speed for the given conditions. By plotting
fuel consumption curves for different boat and
weather conditions, you can understand how
fuel consumption, economy and range vary with
different conditions.

When you first get your Navman diesel flow
system installed on your boat, perform a test
run and plot a fuel consumption curve. For your
first test run, choose a calm day, with light wind
and little current; have a typical load aboard and
a freshly cleaned hull.

Then you can plot other fuel consumption
curves for different boat, weather or sea
conditions. Compare these with your first curve
to see how your boat’s performance changes
with conditions. These curves will be the
reference curves for your boat. As time goes by
you can refer back to this set of reference data

- you can plot another fuel consumption curve
under the same conditions and compare it to
the reference curve to check how your boat’s
performance is changing over time.

To plot a fuel consumption curve for given
conditions:

1 Take a series of readings of the fuel flows

and boat speed at different engine revs
and fill out the fuel consumption table
(see section 3-1)

2 Plot the data from the fuel consumption

table on a graph. Either photocopy the
graph on the next page or download a
copy from www.navman.com. On the one
graph, plot:

a Boat speed (column 5) against engine

RPM (column 1)

b Economy (column 6) against engine

RPM (column 1)
Section 3-2 shows a typical graph.
3 Interpret this curve to understand your

boat performance (see section 3-2).

Diesel fuel flow sensor kit Installation and Operation Manual

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1.2

Economy - L / nautical mile

1.0

0.8

0.6

0.4

0.2

0

Displacement Craft

18

10

15

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9

6

3

Speed - knots

Diesel fuel flow sensor kit Installation and Operation Manual

0 500 1000 1500 2000 2500 3000

0

Economy - L / nautical mile

6

5

4

3

2

1

0

Planing Craft

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Diesel fuel flow sensor kit Installation and Operation Manual

25

20

15

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10

Speed - knots

5

0 500 1000 1500 2000 2500 3000

0

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3-1 Fuel consumption table

Photocopy this page or download a copy from www.navman.com

Date Weather Conditions
Vessel Sea State
Displacement
Load aboard
Gearbox ratio Passengers aboard
Engines Water Tanks
Fuel Tanks
Propeller
Max. Fuel Capacity
Working fuel capacity (max x 0.9)

Notes on filling out this table

Start at a slow speed. Allow a minute or two for
the boat to settle to its speed and trim and for
the display readings to stabilise. Then write the
displayed fuel flow(s) and boat speed in a line
of the table on the right, as described below.
Then increase the engine revs by another
100 or 200 rpm, wait a minute or two for the
readings to stabilise and repeat the readings.
Take readings up to the maximum service RPM
of your engine.

Column 1 - Engine RPM

Use the Navman tachometer reading if
possible, to be sure of accurate results. Write
the engine RPM in column 1.

Columns 2 and 3 - Fuel consumption

Units are litres or gallons - we presume you will
want to work in the units you are familiar with,
and that you have set-up the system display to
work in gallons or litres.

For a single engine boat, write the flow rate in
column 2. For a twin engine boat, write the port
engine flow rate in column 2 and the starboard
engine flow rate in column 3. The numbers for
each engine on a twin engine boat should be
very similar.

Column 4 - Total fuel flow rate

This is just the sum of the port and starboard
engine figures. Add together the flow rates
in column 2 and 3 and write the sum in
column 4.

Column 5 - Boat speed

Write the boat speed through the water in

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column 5. Remember that speed through the
water is not the same as GPS speed if there
are any tidal or other currents.

Column 6 - Economy

If there is a speed instrument connected to the
display then this number can be read directly
for each rpm setting. Write the economy in
column 6. Otherwise, to calculate gallons
per nautical mile divide the consumption in
gallons/hr (column 4) by the speed in knots
(column 5); or to calculate Litres per nautical
mile divide the consumption in L/hour (column

4) by the speed in knots (column 5). Write the
answer in column 6.

Column 7 - range

This is for future reference. Note - please use
the range calculated as an indication, rather
than as a range that you know you can achieve.
For safety’s sake it is strongly recommended
that the calculation is done using 90% of the full
fuel capacity - that will leave 10% of the tank
as a reserve. Call this 90% value the working
capacity of the fuel tank. Also note that the
range would apply only in calm conditions

- difficult wind or sea conditions will drastically
reduce the distance you can go on a full tank.
A more heavily loaded boat will also have its
range reduced.

To get the maximum range for each engine
rpm setting, take the economy (the number
in column 6) and multiply it by the working
capacity of the fuel tank. Write the range in
column 7.

Diesel fuel flow sensor kit Installation and Operation Manual