The system installs flowmeter in front of the vacuum pump and behind the vapor recovery separator in the return pipeline of the vapor recovery device. When it works, the flowmeter measures the flowrate of return air and generates a signal 485. The data acquisition unit will collect and convert it into cumulative flow, meanwhile, it will measure the vacuum pump and calculate the average flowrate. What’s more , it can also read the fueling pulse signal of the fuel dispenser and convert it into the corresponding liquid volume and flowrate. The ratio of return air volume to liquid volume is the air to liquid ratio in the process of vapor recovery. Install differential pressure transmitter to the lower end of unloading vapor collection port or the pressure vacuum valve of the vent-pipe to measure the pressure of tank. The output analog signal will be collected and converted by data acquisition module. According to the range of regular fluctuations of the pressure value in the process of vapor recovery, and the falling rate and number of the pressure value in the static state, it is determined whether the dynamic back pressure and airtightness indicators of the pipeline meet the requirements, so as to check whether the vapor recovery device is working normally .



Name and specification of system components

IPC control box

IPC control box

  • Specification: VRCB
  • Protection grade:IP20
  • Operating temperature:-10℃~60℃
  • Power supply: 220V,±15%
  • Test amount:16 nozzles
  • Host interface:Ethernet、USB 、RS232 、RS485
  • Dimension: 490mm× 340mm× 150mm;

Data acquisition unit and safety barrier

  • Specification:VRDC-1
  • Material:Cold-roll steel sheets
  • EX-mark:EXiaIIBT3Ga
  • Dimension(Length×Width×Height mm):230×120×60mm
  • Flow sensor model:PURECLEAN-VRM-820(Figure 4)
  • Intrinsic safety parameter:Uo≤16V,Io≤400mA,Po≤6.4W,Co≤2.75μF,Lo≤0.1mH Note:
  • Description:The device and safety barrier are installed in the control box of safe area.
Data acquisition unit and safety barrier
Roots flowmeter

Roots flowmeter

  • Specification:HYLC-15
  • EX-mark:ExiaIIBT4
  • Type:Waist wheel
  • Dimension:DN15
  • Accuracy level:1.5
  • Flow range:0.25~6m³/h
  • Operating temperature:-40~60℃
  • Humidity:<90%
  • Pressure range:0.3MPa(Figure 5)

Pressure sensor

  • Specification:VRPS-1
  • EX-mark:Ex ia IIC T6Ga
  • Voltage:DC24V
  • Signal output:4~20mA
  • Suction distance:-3000Pa~3000Pa
  • Repeatability error:±0.5%
  • Permissible error:Not lower than±1%
Pressure sensor
Gas concentration transmitter

Gas concentration transmitter(Optional)

  • Specification:VRCS-1
  • Explosion-proof grade:Exd IIC T6 Gb
  • Power supply:DC24V
  • Measurement range:0-30000ppm
  • Signal output:4~20mA
  • Operating temperature:-40℃ ~60℃(Figure 7)
  • Relay:Two sets(One set is used for gas alarm output,and the other is used for failure alarm output), 1A / 24 VDC
  • Description:Installed in the return pipeline of Stage Ⅰ vapor recovery device and the exhaust vent of vapor processing device,to monitor the vapor
  • leakage and emission concentration of the return pipeline and oil pipeline respectively.

Temperature transmitter

  • Specification:VRTS-1
  • Explosion-proof grade:Ex d IIB T4
  • Temperature range:-50℃~100℃
  • Voltage:DC24V
  • Signal output:4~20mA
  • Insertion depth:L=100mm
Temperature transmitter
Air to liquid ratio electronic regulator

Air to liquid ratio electronic regulator

  • Specification:VRDV-50
  • EX-mark:Ex d IIC T3 Gb
  • Voltage:DC24V
  • Power:8.2W
  • Ambient temperature:-40~50℃
  • MPA:0.35MPa or vacuum