Daviteq fuel flow meter

Visual Inspection of Fuel Flowmeter

Before installing the flowmeter, it is essential to perform a visual inspection to identify any potential defects that may have occurred during transportation, storage, or handling. Check for the following:

• Visible damage to the case, fittings, mounting plate, display, interface cable, and/or connectors.

• Backlash or gaps between constituent parts.

  
  

Prior to installation, it is recommended to verify the connection of the fuel flowmeter to the power supply:

1. Supply a minimum flow of fuel or air (10-40 l/h, 0.3 bar) to the flowmeter.

2. Check if the signal LEDs on the flowmeter case blink during fuel/air supply.

If any defects are detected, contact the supplier.

Preparation for Installation

Before installing the flowmeter, thoroughly inspect the vehicle/engine/genset to ensure that the installation is feasible.

1. Inspect all fuel lines for damage or fuel leakage  and make sure that there is no leakage ;Otherwise, customer eliminates leakage 

2. Check engine operation for 5-10 minutes at idle  and make sure that the engine runs evenly and does not stall and there is no air in the fuel system ;Otherwise, customer eliminates malfunctions 

3. Check engine operation for 5-10 minutes under load or when vehicle is moving  and make sure that the engine runs evenly and does not stall ;Otherwise, customer eliminates malfunctions 

4. Check the onboard voltage with voltmeter  and make sure that a 12-v onboard power system has operating voltage of 10-18 v and a 24-v onboard power system must have operating voltage of 18-32 v ;Otherwise, customer eliminates malfunctions 

5. During the installation of flowmeter check the presence of gases in the return line  and make sure that no foam or air bubbles in fuel ;Otherwise, deaerator installation or elimination of malfunctions required

6. Check the amount of excess fuel removed through the return line from injectors  and make sure that the measurement error increases with a significant amount of excess fuel, since excess fuel flows back into the tank and is re- counted by flowmeter ;Otherwise, change the connection of the return line from injectors so that the measurement is correct

7. Check the pressure in fuel system with manometer  and make sure that hydraulic resistance of the chosen flowmeter in the nominal mode does not reduce the pressure by more than 5% ;Otherwise, compare the values of pressure in fuel system before and after flowmeter installation

8. Check the “ground” of the vehicle/engine/genset and make sure that the resistance between connection point and clamp “-“ of a battery terminal does not exceed 1 ohm; Otherwise, customer eliminates malfunctions

• The vehicle/engine/genset inspection protocol should be completed and signed based on the inspection results. The customer must address any malfunctions indicated in the protocol before installing the flowmeter.

• The maximum and minimum fuel consumption values in the supply and return lines can be found in the technical specifications of the vehicle's pump or by measuring the volume of fuel flowing from the return line into a measuring container.

• It is not recommended to install a differential flowmeter if there are air bubbles in the supply or return fuel lines. In such cases, a deaerator should be installed.

General Installation Instructions

Required Tools and Materials:

- Fuel flowmeter

- Mounting kit (to be purchased separately)

- Hand tools (sets of box wrenches, socket heads, and screwdrivers)

- Two fuel filters with attached washed hoses and clamping clamps to protect the chambers from contamination during initial installation.

- Flowmeter chamber with transparent cover (optional) to detect the presence of gases in the measured fuel

Installation Guidelines:

- The flowmeter can be mounted vertically, horizontally, or at an angle. For optimal performance, it is recommended to mount the flowmeter horizontally. If the fuel flow direction (indicated by an arrow on the flowmeter case) is not horizontal, ensure the flowmeter's outlet is positioned higher than its inlet.

- Avoid damaging the cable and fuel lines during installation.

- Secure the flowmeter to the surface at a minimum of three points.

- Do not drill the vehicle's base frame when installing the flowmeter. If securing a mounting plate with screws is not possible, use spot welding.

- Ensure the installed flowmeter is not exposed to direct water jets from a high-pressure cleaner.

Installation Rules

1. When installing a flowmeter on any equipment, attach additional plastic fuel filters (or metal ones if there is high pressure in the system) directly in front of each chamber, and perform the initial start. Additional fuel filters will help avoid the ingress of dirt, particles of rubber, cord, and metal resulting from cutting the fuel lines and tightening the threads. Additional filters can be dismantled after half an hour of system operation.

2. If the fuel system is highly contaminated:

- Perform maintenance of the vehicle and replace regular filters.

- Install additional filters if there are no regular ones.

3. When connecting the fuel lines, ensure that flanges and threaded connections are clean.

4. Use only new sealing washers from the mounting kit.

5. Protect the vehicle's fuel lines from external destructive influences.

6. Do not reduce the internal cross-sections of fuel lines at bends.

7. Fasten the fuel lines to the vehicle with ties every 0.3 meters.

8. Ensure fuel lines have a small margin in length to compensate for temperature changes.

9. Do not install the flowmeter on vehicle elements that are subject to strong vibration and heat.

10. Connect rubber fuel lines to the elements of the fuel system using pivot brackets or flow-through fittings and secure them with hose clamps or hose crimps (recommended).

11. Exclude air from the fuel system after the flowmeter is installed.

12. Seal all detachable and threaded connections of the fuel line situated in the sections “engine – flowmeter” and “flowmeter – engine,” including a standard relief valve.

Note:

• Do not use a fuel flowmeter with a maximum flow rate lower than the actual flow rate of the equipped vehicle or diesel generator.

• It is not recommended to use internal or external filters with petrol gauze (cell area less than 0.6 microns) in the connection diagram, as this may cause fuel system failures at subzero temperatures.

Installation of Flowmeter on Diesel Engine Using the "Differential" Diagram

The fuel circulation pattern in the system remains unchanged during differential measurement. The supply chamber of the differential flowmeter is installed in the engine's fuel supply line, while the return chamber is installed in the return fuel line. Fuel consumption is calculated as the difference between the measured flow values in the supply and return chambers.

The original fuel system is illustrated in below figures.

where 1 – fuel tank, 2 –supply line, 3 – return line, 4 – return line from injectors

where 3 – return line, 5 – LPFP, 6 – fine filter, 7 – HPFP, 8 – relief valve

Original fuel flow system as below:

1. Fuel is drawn from tank 1 by the Low-Pressure Fuel Pump (LPFP) 5 through the supply line 2.

2. The fuel is then pressurized and sent to the fine filter 6.

3. The purified fuel is delivered to the High-Pressure Fuel Pump (HPFP) inlet 7.

4. Excess fuel from the HPFP returns to tank 1 through the return line 3, regulated by a relief valve 8, which maintains the required pressure in the fuel supply system.

Installation steps

• Step 1: Disconnect the fuel lines connected to HPFP: fuel supply from the fine fuel filter and the return line with the relief valve 8

• Step 2: Install and connect fuel flowmeter  using provided accessories

  
  

  

• Step 3: Connect the supply chamber inlet (marked as “F” on flowmeter case) to the fine filter outlet.

  

  
  

• Step 4: Connect the supply chamber outlet to the HPFP inlet.

• Step 5: Connect the HPFP outlet to the return chamber inlet (marked as “R” on flowmeter case).

• Step 6: Connect the return chamber outlet to the return fuel line with the help of previously removed relief valve 8.

Note:

• If the fuel system operates properly, the return line from injectors 4 does not contain a significant amount of fuel and can be ignored. However, it is recommended to check the flow rate in this line.

• If the fuel consumption in the return line affects the measurement result by more than 2% of the engine's fuel consumption, it is recommended to connect the return line from the injectors to the HPFP inlet.

Deaerator Installation

Air bubbles may be present in the engine's return line. To detect their presence, lower the return pipeline into a transparent container. The presence of air increases fuel consumption in the return line, leading to a higher measurement error in the engine's fuel consumption as determined by the flowmeter.

If there are air bubbles in the return line, they must be removed by installing a deaerator.

Install the deaerator in front of the return measuring chamber of the flowmeter.

Connect the outlet of the engine return line to the deaerator inlet. The purified fuel will then be delivered to the flowmeter inlet.

The separated air contains a small amount of fuel, which could leave stains under the engine. To prevent diesel stains and comply with environmental requirements, it is recommended to connect the gas outlet to the return line behind the flowmeter.