Main Structure and Operating Principle of fuel tanker truck

Our fuel tanker truck for transporting light fuels include fuel tanker and refueller which are used for transporting and filling light fuels such as gasoline, diesel and kerosene and, if necessary, for transporting and filling other noncorrosive liquids. Our oil truck is featured by rational design, fine manufacturing, fine materials and excellent
performance. And the technical specifications all comply with the specifications of GB18564 and QC/T653.

“Lv Ye” oil truck consists of class II automotive chassis, tank body assembly, pipeline system, oil hose,
ESD chain and safety guard, etc. (see Figure 1):

Figure 1
Figure 1

1 Class II chassis  2 Tank body  3 Manhole cover   4 Power takeoff and drive system  5 Side safety guard   6 Pipeline system   7 Fire extinguisher   8 ESD chain   9 Rear bumper   10 Back stair

Our oil truck adopts domestic and abroad formed automotive chassis. This Instruction does not have detailed description of chassis in terms of its structure, principle, performance parameters and operation & maintenance. Please refer to the Operating Instruction supplied with the chassis.
1. Tank body assembly
Our tanks are metal-based atmospheric tanks mainly including carbon steel tank, stainless steel tank and aluminum alloy tank and each tank body has an operating pressure no greater than 72 KPa and an ambient operating temperature of -40 to +40 °C.
A tank body has an oval section or a round-square section (a rectangle with circular arc). The head is processed automatically by a computerized numerical control (CNC) beading machine for attractive appearance and high rigidity. The shell is made of jointed plates arranged in longitudinal joints and welded with full-automatic gas shielded welding method and the jointed plates are rolled to shape the tank as a whole with nice-looking appearance and excellent straightness. The shell and the head are welded through the penetration butt welding method.
Inside the tank body there is a swash plate installed and in some tanks there is a longitudinal oil baffle plate installed, in order to alleviate the impact of the oil inside the tank body to the head and shell.
Setting tank and drain outlet are set at the bottom of the tank body so that the drain outlet can be opened occasionally as appropriate to emit water and dirt stored in the setting tank. The setting tank is also integrated with an oil drain hole which can be used for forming a fuel tanker by connecting an oil drain line to it or forming a refueller by connecting the inlet pipe of the oil pump to it.

The upper part of the tank body is equipped with a safety frame which can ensure the safety of the user during an operation upon the tank body and can also contain the oil spilled during filling of oil, so that the spilled oil can be exported through the overflow pipe at the front part of the tank body to avoid contamination to the outside surface of the tank.
2. Manhole cover assembly
For the sake of easy access by personnel into the tank body for repair, a manhole cover assembly is installed on the top of the tank body. The manhole cover can be completely removed by loosening the fixing bolts of the manhole cover. If the oil or gas in the tank is completely discharged and the tank presents no danger,
the operating personnel can go inside the tank body. In order to make it easy to check the oil in the tank body and fill oil in the tank, the manhole cover has an oil filler cover. Rotate the hand wheel, raise the pressing beam and free the retaining ring from the hook base to open the oil filler. The user can fill oil in via an oil hose put through this oil filler.
In order to adjust the pressure differential between the interior and exterior of the tank, the manhole cover also has a breather valve. The air outlet valve opens when the internal pressure is 6-8 kPa greater than the external pressure and the air inlet valve opens when the internal valve is 2-3 kPa less than the external pressure, so that the interior and exterior of the tank body keep constant air exchange. Usually, a tank with a small volume shall have at least one breather valve and a tank body with volume greater than 12 m3 shall have two breather valves.
After a period of service of the tank body, it’s necessary to check the breather valve for operating condition.
Loosen the exterior screws and remove the upper part of the breather valve. Rotate the adjusting nut at the lower part of the valve body and move the lower valve body to adjust the pressure of the air outlet valve. Rotate the adjusting nut at the upper part of the breather valve and move the valve stem to adjust the pressure of the air inlet valve. Malfunction of breather valve will possibly lead to deformation of tank body during oil pumping.
It’s recommended that the user regularly check the breather valve for operating condition to make sure that its operating pressure is reliable.
3. Power takeoff and drive system
Power takeoff and drive system mainly consists of power takeoff, control system, drive shaft, and oil pump, etc.
The function of power takeoff is to transmit the power of the engine through power takeoff, via drive shaft to the oil pump and drive the oil pump.
The control system of power takeoff applied by our company can be divided into manual mechanical manipulation and pneumatic manipulation:
Manual mechanical manipulation: step down the clutch pedal first, pull the control handle of the power takeoff so as to realize the engagement of the power takeoff gear and the gear of gearbox, and then loose the clutch pedal to transmit the engine power to the oil pump through drive shaft.
Pneumatic manipulation: realize the transmission of power through altering the on-off of air circuit. There is a power takeoff control switch on the instrument panel of the cab. Step down the clutch pedal first, then pull the power takeoff switch and connect the air circuit; compress the air via the air reservoir to the air cylinder of the power takeoff so as to drive the piston inside the cylinder, and drive the shifting fork to engage output shaft gear of the power takeoff with its input shaft gear, then loose the clutch pedal to realize the transmission of power. Drive shaft: the drive shaft of the oil pump adopts cross cardan joint at both ends and high frequency
welded pipe in the middle, with flexible spline at one end.
Oil pump:
(1) Oil pump is one of the key parts of the refueller. See the onboard Oil Pump Operating Instruction for the structure and principle, etc. of oil pump.
(2) Operation, maintenance and upkeep of oil pump:
 It’s forbidden to start the pump when the pump is not fulfilled with liquid yet, so as to prevent from damaging pump parts.
 Before pump operation, inspect the pump steering and every joint part for tightness and check every valve switch. It’s not allowed to start the pump when the outlet valve is closed to prevent from accidents.
 During pump start-up, the rotate speed shall be accelerated slowly at a low speed and maintained at corresponding rotate speed without overspeeding or speed fluctuation.
 Long time of idling of pumps with safety valve is not allowed without oil extraction. Otherwise the oil temperature will rise, which may lead to accidents.
 Pay attention to the reading of the pressure gauge and the vacuum gauge during pump operation. If the reading of the pressure gauge is too high, it indicates that the lift is too high or that the outlet pipe is blocked. If the reading of the vacuum gauge is too high, it indicates that the suction head is too high or the suction line is blocked.
 The filter shall be regularly cleaned to prevent from blocking the pipe and influencing the flow rate.
Regularly check the safety valve for oil drain pressure.
 Rust protection shall be provided for the pump if it’s intended to be out of service for a long time.
 Supply calcium grease to the bearing every 6 months.
 Stop the pump before shut-down, then close the outlet valve of the pump.
(3) Operation, maintenance and upkeep of SYCB double-gear oil pump:
 Flexible-shaft wire controller can be installed in the control cabinet or the cab. Adjust the control area of the wire to locate the locking ball of the control handle in the ball socket, and the middle mark on the shifting fork draw bar aligns with the reference level on the housing of the controller.
Right now, the two pumps work simultaneously. Push or pull the handle forward or backward until the shifting fork draw bar is completely pulled out or pushed in, and then pump A and B will work separately.
 In case of changing the operating condition of the pump, it shall be performed when the pump is not running to prevent from damaging the gear.
 There shall be sufficient lubricating oil within the gear case. Check it with a level rod.
 Inspect the pump steering before starting the pump.
 It’s forbidden to start the pump when the pump is not fulfilled with liquid yet, so as to prevent from damaging pump parts.
After the pump is started, if there is unusual sound or vibration, eliminate them before starting it up again.
 Supply lubricating grease to the bearing every 6 months.
4. Pipeline system assembly
(1) In the pipeline system of a fuel tanker, a two-way ball valve is installed on the oil drain line to control oil drainage. It’s open when the handle of the ball valve is parallel to the pipeline; it’s closed when the handle of the ball valve is vertical to the pipeline. It takes great effort to open the ball valve at first use. After several times of use, it can be opened and closed with less effort.
(2) In our company, for pipeline system of refueller, there are two types of structure: the first one is capable of oil discharging by gravity flow, dynamic oil discharge without metering and dynamic oil discharge with metering. See Figure 2 for its specific structure principle. Compared to the first structure, the second has an additional straight-through ball valve (i.e. able to return to the tank). See Figure 3 for its specific structure principle.

Figure 2
Figure 2

1, 6 – Three-way ball valve  2 – Coarse strainer  3 – Oil pump 4 – Flowmeter  5 – Fine filter   A, B, C – Male joint

Figure 3
Figure 3

1, 7 – Three-way ball valve 2 – Coarse strainer  3 – Oil pump 4 – Flowmeter   5 – Fine filter  6 – Straight-through ball valve  A, B, C – Male joint
(3) Three-way ball valve
There is a pit on the top of the valve stem of three-way ball valve. Turn the handle of the ball valve and the pipe orifice against the pit is closed and two other pipe orifices are connected at the mean time.
(4) Coarse strainer assembly
Coarse strainer assembly is the safety guard of oil pump, installed in front of the oil pump inlet, preventing impurities from entering the oil pump. During the first few times of using a new tank, remove the flange and hold the handle of the coarse strainer to take out the filter element for cleaning after using. During the following course of use, clean the filter element depending on the cleanliness of the oil quality or replace damaged filter element. The filter element shall not be taken out during use. Otherwise, the wear of oil pump will be worse or components within the oil pump will be damaged.
(5) Fine filter assembly
Fine filter assembly is the safety guard for the flowmeter. It can filter the oil for foreign matters and dirt, preventing foreign matters from entering the flowmeter and damaging the components. Fine filter assembly is also the last stage of filtration of the oil outlet. It ensures clean oil sucked from the tank body. During the first few times of using a new tank body, remove the flange and hold the handle of the fine filter to take out the filter element for cleaning after using. During the following course of use, clean the filter element depending on the cleanliness of the oil quality or replace damaged filter element.
(6) Flowmeter
Flow meter is a metering device used during refueller operation. We adopt elliptical rotor flowmeter (roots rotor flowmeter is also optional as required by the user). Flowmeter is a precise device which does not needed to be adjusted or disassembled by the user during service.
(7) Quick-change connector at the oil outlet
The pipeline system of refueller has three quick-change connectors, i.e. pump inlet, pump outlet and flowmeter outlet. With quick-change connector, it’s possible to quickly connect to the oil hose.
5. Oil hose
Every truck produced by our company has 2 oil hoses that are placed respectively in the hose chambers at two sides of the tank body and are used for loading/unloading of oil.
6. ESD chain and static electricity conducting plate
In order to keep fuel tanker truck safe during transportation and prevent fire caused by static electricity, an ESD chain is fixed at the tail of every truck. One end of the ESD chain is connected to the tank body and the other touches the ground, so that the electrostatic charge generated during travel of the truck is transferred to the earth, therefore the ESD chain shall never leave the ground during operation of the oil truck. If the ESD chain has shortened due to friction, the fixing bolts at the rear of the frame can be loosened to extend the ESD chain;
if the ESD chain is no longer extendable, it shall be replaced with a new one in time. For easy connection to the oil depot or ground wire of petrol station, our products are equipped with static conductive connecting copper plate at an apparent part on the rear of the tank body (e.g. the lower part of oil drain ball valve). When using it, draw the ground wire of the oil depot or petrol station to the truck and fix the clamp to the electrostatic conductance plate.Refuellers have additional static electricity conducting disks which shall be connected to the grounding device of an oil depot or petrol station during loading/unloading of oil. A static electricity conducting disk has a grounding bar which is inserted into the ground when oil is being loaded/unloaded at a location where no grounding device is available and is secured by a static electricity conducting disk clamp.
7. Fireproofing and silencing apparatus Our fuel tanker truck is all equipped with flash hider for easy access to oil depot or petrol station. Additionally,clients can select optional fireproofing silencer. Flash hider is not necessary for trucks with fireproofing silencer.
8. Safety guard
Any of our fuel tanker truck has safety railing on both sides and such railing is removable. The rear part of any truck has rear bumper.