VAF Instruments Viscosity
and Flow Meter Parts
VAF Instruments of Dordrecht in the Netherlands makes the ViscoSense sensors behind fuel viscosity control, PT2 fuel flow meters and the T-Sense and TT-Sense meters on the propeller shaft. Each instrument is quoted from its own label: the type, the serial and the box or controller it reports to.
VAF instruments met in engine rooms
VAF Instruments is based in Dordrecht and has been part of the Aalberts group since 2018. On board its name turns up in three places: the viscosity sensor and controller ahead of the engine, the meters that count the fuel each consumer burns, and the torque meter on the shaft line. The cards follow those three places, because each place has its own labels and its own parts list. For the viscosity controller, the fuel viscosity-temperature calculator gives the heating temperature for a set viscosity from two measured points of the fuel, and the viscosity units converter turns an older figure in Saybolt seconds into cSt.
ViscoSense 3 · ViscoSense 3D
In-line sensors that read fuel viscosity from a small pendulum vibrating in the fuel. The ViscoSense 3 reads viscosity and temperature; the 3D reads density as well. The sensor is wired to an interface box, and the viscosity controller uses the reading to trim the fuel heating. Sensor and box carry separate labels and part numbers, and a ViscoSense 3 box is not read as a 3D box. Older ViscoSense 2 installations are still met in service and are quoted from their own labels.
Viscotherm
Viscotherm is the name of VAF's earlier fuel viscosity control equipment, in which a controller holds viscosity by regulating the fuel temperature. For Viscotherm installations VAF offers a retrofit: a housing of the same shape that takes a ViscoSense sensor. Whether a ship still runs the original unit or the retrofit is read from the labels and the housing, not from the name in the machinery list.
J5025PT2 · J5040PT2 · J5050PT2
Positive displacement meters with sliding vanes, made for measuring fuel consumption on board. The full type is stamped on the meter body and is copied exactly, together with the serial; two meters on one fuel line are often of different types. The meter body and the pulse sensor that reports its count are separate lines on a request.
T-Sense
An optical torque meter on the propeller or drive shaft that reports torque, shaft speed and shaft power. Some of its parts turn with the shaft and some sit beside it, and each carries its own label. The fault shown on the display and those labels decide which part goes on the request.
TT-Sense
The same optical approach with propeller thrust measured as well as torque. A TT-Sense is quoted from its own labels and parts list, never from a T-Sense list, even though the two meters look alike on the shaft.
VAF ShaPoLi
A shaft power limitation system for EEXI: it compares the shaft power read by a torque meter with the limit set for the ship and raises an alarm when the limit is passed. The torque meter and the ShaPoLi units on the bridge are separate lines with separate labels.
VAF Instruments · Aalberts
VAF Instruments is a Dordrecht company that became part of the Aalberts group in 2018. Labels and manuals read VAF or VAF Instruments; either is enough to start, with the type and serial.
KRAL OMP · Nakashima Shaft Horsepower Meter
A KRAL OMP fuel flow meter is read on the KRAL page, and a Shaft Horsepower Meter on a Nakashima propeller line on the Nakashima page. Their parts share nothing with a VAF instrument.
What usually brings a VAF instrument onto a request
These instruments seldom wear out the way a pump does. A request usually starts with a reading that no longer makes sense, and the first job is to decide whether the instrument or the system around it is at fault.
Viscosity that will not hold
When the controller cannot keep the set viscosity, the heater, the steam or thermal oil valve, a fuel change and the sensor are all suspects. The trend on the controller display and the fuel in use at the time show whether a sensor line belongs on the request at all.
A reading that does not match the fuel
If the reading disagrees with the bunker analysis, the sensor is cleaned and checked as its manual describes before it is condemned. For the delivered quantity itself, the bunker quantity calculator turns the volume at tank temperature into the volume at 15 °C and tonnes from the density in that analysis. Send the reading, the analysis and the sensor label together, so the reply can tell a sensor fault from a fuel question.
A consumption figure that drifts
A worn measuring chamber, a blocked strainer upstream or a failed pulse sensor all show as a wrong total. Say what was found, since the meter body and the pulse sensor are ordered separately; the fuel consumption calculator helps compare the total with the engine's specific consumption.
A power reading lost after shaft work
Work on the shaft line at docking can disturb a shaft meter. Note what was done to the shaft, what the display shows and when the reading was last plausible before any part is ordered.
VAF items that appear on RFQ lines
Grouped by instrument; each line should name the instrument it belongs to and carry the label of the part itself.
- ViscoSense 3 and ViscoSense 3D sensors, by type and part number
- Interface boxes for ViscoSense sensors, by the label on the box
- Viscosity controller units and their displays
- Viscotherm retrofit housings for ViscoSense sensors
- PT2 flow meters by full type, and their pulse sensors
- T-Sense and TT-Sense parts on the shaft and beside it
- Cables and connectors from the instrument's parts list
- Seals and gaskets for sensor housings and meter bodies
What to send for a VAF instrument
These items tie the request to one instrument and one parts list before anything is priced:
- Instrument type and serial number from the label, photographed as they read
- For a viscosity system: the sensor label, the interface box label and the controller type
- Software version shown by the controller or display unit, where it shows one
- For a flow meter: the full type stamped on the body, such as J5040PT2, the serial and the line it measures
- For a shaft meter: T-Sense or TT-Sense, the serial, and the fault or reading on the display
- The fuel grade in use and, for viscosity questions, the latest bunker analysis
- Whether the shaft meter also feeds a ShaPoLi or performance monitoring system
- Photographs of the labels, the display and the instrument as installed
How a VAF request is worked
Each line is reviewed as a genuine part or a checked alternative, and the route is confirmed before the quote. For sensors and electronics that review stays on the OEM-route.
OEM-route for sensors and electronics
Viscosity sensors, interface boxes, controllers, pulse sensors and shaft meter electronics are quoted on the OEM-route for the type and part number on the label. No other make's sensor is proposed in their place.
Standard items on a checked path
Gaskets, O-rings, cable glands and fixings can be catalogue items behind a VAF part number. Where the owner accepts it, they go on a checked alternative path once size and material are confirmed from the parts list; the O-ring size finder helps with the line.
One instrument, one set of lines
A sensor and its interface box, a meter body and its pulse sensor, the turning and fixed parts of a shaft meter: each is a line of its own with its own label, kept under the instrument it belongs to.
Figures you can check on board
A ViscoSense 3D reads density and viscosity, the two inputs of the CCAI calculator. Torque, speed and power from a shaft meter should agree in the shaft torque calculator; if they do not, say so in the request.
VAF instrument parts — questions engineers ask
Our machinery list says Viscotherm. Can a ViscoSense part be quoted for it?
Only after the labels are read. VAF offers a retrofit for Viscotherm installations, a housing of the same shape that takes a ViscoSense sensor, but changing the sensor type is a decision for the ship. Send the plate of the unit on board, the controller type and photographs; the reply states which parts belong to what is actually fitted.
Is a ViscoSense 3 interface box the same as a 3D box?
No. The 3D also reads density, and its interface box carries a different part number. Copy the label on the box and on the sensor exactly, and say which controller they report to.
Can a flow meter be quoted from the pipe size?
No. The full type stamped on the meter, such as J5025PT2, and the serial fix the meter; the pipe size does not. If the meter feeds a fuel monitoring system, name that system as well.
Our shaft power reading disagrees with the engine figures. Where do we start?
With the display and the labels. Note torque, speed and power at the same moment and check them against each other in the shaft torque calculator. Then send the meter type, T-Sense or TT-Sense, its serial and any fault on the display.
Can you offer a cheaper sensor from another maker?
No. A viscosity sensor or a shaft meter works with the electronics it was built for, so only the part for the type and part number on the label is quoted, on the OEM-route. If it cannot be found, the reply says so plainly.
Is Vessel Core connected to VAF Instruments?
No, and there is no agreement of any kind. Vessel Core holds no distribution, representation or partnership agreement with VAF Instruments, and quoting a component against one of its designations implies no approval by the maker and no claim of interchangeability.
Start with the label on the instrument
Send the instrument type and serial, the label of each sensor, box or meter on the order, the controller or display type with its software version where shown, and what the display reads. If only part of that is to hand, send what you have.
