Gas Station Equipment Solution

3

Gas Station Equipment Solution

Gas Stations are designed for filling motor vehicles with Liquefied Petroleum Gas(LPG). Gas Stations offered by Magna Engineering allow fiscal metering of LPG delivery, custody transfer and storage by mass, volume and by reduced volume. Our solution combines Micro Motion flow metering system with VRF controllers. It is fully compatible with AZS-Service computer system. The system can run reports on LPG delivery, custody transfer and storage covering any specified period of time by mass with accuracy as per LPG fiscal metering standards.

System operation modes are assigned from flow controller and executed automatically via switching the corresponding solenoid.

 

Following operation modes are available:

 1. Unloading of LPG tank trucks to Gas Station storage tanks.

Gas is discharged with Corken Z2000 truck pump through mass flowmeter and directed to storage tanks. The process occurs when steam line valves are closed. Discharge rate is controlled with flow controller. Decrease of rate compared to the set value launches switching of the solenoid valves that close fluid line and open steam line. Steam phase is diverted back through mass flowmeter until the pressures are balanced within the tank truck and the storage tanks. After that steam line is closed and valves of the fluid line are open. Tank filling level is controlled with DIGI MAG magnetostrictive level transmitter (Italy) connected to VRF controller directly.

  1. Custody transfer.

Gas is withdrawn from storage tanks with Corken FD150 or Blackmer LGL 158A pumping unit and delivered through mass flowmeter to filling nozzle equipped with delay valve, located upstream, that allows controlling amount of LPG being unloaded. Should there be no filling for more than 15 minutes the system launches process purge through gas return line from dispensing unit to ensure unloading of liquid LPG phase. There is a VRF controller and a 3 line display showing gas price per liter, number of unloaded liters and total payment due at the point of custody transfer in the dispensing unit enclosure.

  1. Stored LPG weight control.

Calculation of LPG stored in Gas Station storage tanks is maintained basing on LPG density measurement by mass flowmeter and tank filling level data received from level transmitters. Density is measured automatically during the whole shift via process purges, performed against time schedule set in the flow controller. In this case gas pump withdraws gas from storage tanks and directs to mass flowmeter diverting the flow back to storage tanks. Flow controller calculates weight of stored LPG basing on the stored volume and actual density. During this procedure solenoid valves block filling tanks and gas unloading functions. One of significant system features is tank calibration with LPG since withdrawing gas from tank to tank and obtaining data on the volume passed by mass flowmeter and filling level metering allow for development of calibration tables with 1 mm accuracy.

Gas Stations manufactured by Magna Engineering differ from the other process solutions utilizing LPG volume metering due to the following advantages:

  • Calculation of delivered, stored and unloaded LPG weight is maintained via direct measurement without any “manual” calculations;
  • There is one VRF controller to cover all calculations and deliver final considered values to cash registering system, while conventional Gas Stations deliver amount of unloaded LPG in liters from flowmeter, product filing level and density (product from storage) from level transmitter and delivered LPG amount by mass or density is input manually;
  • There are no quick wear spools in the system such as flowmeters and by-pass valves;
  • System automation prevents from human factor during switching the operation modes and thus significantly reduces risk of emergency occurrence  due to staff misconduct. (Staff action sequence is shown on the controller display);
  • Mass flowmeter complete with controller can perform continuous monitoring of Gas Station piping integrity and notify staff of revealed leaks;
  • VRF controller exceeds electronic units of gas dispensing units in reliability and service life multiple times. While installation of the software, developed by Magna Engineering, allows any customer required modifications to be made in a timely manner.

 

FEATURES COMPARISON

of LPG  mass flow metering system manufactured by  Magna Engineering and conventional flow metering systems.

  

 

No

Feature

LPG metering type

LPG mass flow metering based on Micro Motion and VRF controller

Conventional LPG metering based on flowmeter (dispensing unit)

1

LPG measuring procedure

Direct measurement of mass  without secondary instruments

Calculated basing on readings from a number of instruments

2

Measurements Accuracy

±0,25% by mass

±1% by volume

3

Output data acquisition procedure

Through one VRF controller switching to all system components

Via data acquisition from each system component

4

LPG Delivery, storage and custody transfer control

Fully automatic solution through VRF controller

Manual

5

Human Factor Influence

No

Yes

6

Gas Station process system and piping integrity monitoring

Automatic

NA

7

Quick wear instrument components

No

Flowmeter , by-pass valve

8

Process maintenance

Not Required

Monthly, according to maintenance procedure

9

Repair

Not Required

Once in

1,5-2,0 years averagely

10

Unloaded LPG amount control

Software,

 via VRF controller

Mechanical,

 via manual instrument setting

11

Service life

No less than 20 years

10 years

12

Introduction of modifications and amendments to electronic unit upon customer request  

In a timely manner,

Since software is developed by supplier   

Impossible

13

Operator action sequence indication.

In Russian,

On electronic VRF controller display

N/A

14

In-house LPG storage tank calibration

Yes

No

 

 

 GAS

Gas Station Equipment list

 

No

Description,

Type, Manufacturer

Quantity, pcs

1

Mass Flowmeter

Micro Motion R 100

1

2

Flow computer

VRF

1

3

Filter

flanged

2

4

Electric pump unit

FD 150

1

5

Ball Valve

DN20

5

6

Ball Valve

DN25

7

7

Ball Valve

DN40

4

8

Ball Valve

DN50

2

9

Electric pump unit

Z-2000

1

10

Shutoff Solenoid valve

DN20

2

11

Shutoff Solenoid valve

DN25

3

12

Non-return valve

DN50

2

13

Non-return valve

DN20

1

14

Safety valve, hydrostatic

ReGo 3127G

6

15

Dispensing hose, gas nozzle

T3

1

16

Dispensing unit enclosure, stainless steel

 

1

17

Level transmitter

DIGIMAG

2

18

Shutoff Solenoid valve

DN40

2

19

By-pass valve

NPOOO BelAvtotransGaz

1

20

Display

 

1

21

Delay valve

DN20

1