Integrated Tank Gauging

Real Time, Web Based Fuel Management with Automated Electronic Tank Gauging

Why do you need Tank Gauging?

  • Any Fuel Management System worth its salt will be able to tell you, in real-time, how much fuel is in any tank on the system – so why bother with the expense of a tank gauge? At first glance, it’s not obvious, but a gauge is invaluable as a check on the rest of the system and for spotting external events such as fuel theft or poor pump calibration.

  • Without a gauge, stock is managed like an accounting ledger – initial stock plus deliveries minus drawings equals current stock. As drawings take place the stock volume decreases, as deliveries are received, the stock is added to. This is commonly known as a Book Stock value.

  • With timely input of the deliveries through the website and real-time transaction updates, the stock figure displayed on the system is always up to the minute. There are, however, issues that mean that the stock in the tank doesn’t match what the book stock says. For example, if a tank was dipped every quarter, and a discrepancy of 2000 litres was discovered, it would be very hard to discover where the fuel had gone. That’s where tank gauging comes in.

Causes of Stock Issues

One of the most common problems is human error. For example, if fuel deliveries are normally 30,000 but then a delivery of 28,000 litres is received, it is likely this is entered (because of habit) as 30,000 Litres – three months later, there’s an unexplainable discrepancy. Looking back at the deliveries, everything looks fine, so it’s difficult to spot without going back through each fuel invoice.

Another problem is pump calibration. A pump will display and tell the fuel management system that it has dispensed, say, 200 litres when in fact, it has delivered 202. Over time, the tank ends up having less in than is calculated by the system leading to stock write-offs. It can work the other way, and the pump delivers 198 litres when it says 200, and you end up with more stock in the tank.

Short deliveries where you are billed for 30,000 litres but only get 28,000, and, finally, there is the possibility of the fuel being stolen from the tank. All of these issues are quickly detected if a tank gauge is fitted.

Is fuel theft from tanks an issue?

In 2017, Jigsaw removed an existing fuel management system installed for over 10 years and fitted a new Jigsaw Eclipse linked to the existing gauge. The end user had complained to their old fuel management supplier for some time that their stock usage figures didn’t align with what they were being invoiced. They had been told to add a tank gauge to the system to try and identify the issue but to no avail.

Within two weeks of the Jigsaw system being fitted, it had spotted and highlighted a discrepancy in fuel stocks occurring as a step fall of around 1000 litres on a Sunday evening. The staff on the site initially didn’t believe that fuel could have been stolen as the site is well run and was manned by security staff at the time the fuel level fell. However, a week later, another 1000 litres went. The Jigsaw system raised e-mail and text alarms, but the security staff on site couldn’t see any issues at the tank.

The day after, a service engineer was called to check the system as the site still thought it must be a hardware problem. The engineer checked the pipework and found a permanent tapping point on the diesel line. From here, a pipe led almost 300 M to a 1000 litre tank buried in a river bank. There was an electric suction pump and a mains socket at this spot, which was wired from a lamp post 100 M away. From the tank, there was a 500 M length of pipe to a more convenient point where barrels could be filled. The whole set-up had been installed and used over many years as vegetation and trees had grown around and over much of the pipework and equipment.

What Type of Gauge?

The Jigsaw system can interface to just about any Tank Gauge Unit with an electronic communications interface. The more common are OLE, Gilbarco Veeder-Root (GVR), OPW, Franklin, Piusi OCIO, I-Level etc. These use various technologies to measure fuel depth and then calculate the volume of fuel from tank dimensions.

The accuracy of the gauge depends on how accurately it can measure the depth of fuel. The least expensive can measure with an accuracy of around 2 cm. The most expensive claim to measure to around 0.1 mm – you get what you pay for. Accuracy of around 5 mm is usually sufficient for good stock management.

Get in Touch:

Jigsaw Systems may be configured in many different ways to suit your business. If you don’t see exactly what you need here, please don’t hesitate to get in touch. The system has been developed with the help of end users in each market sector so we are confident that we can cover any requirements with our systems.

Tank Stock Display

As each fuelling transaction takes place and is sent to the web server, the gauge level is also sent. This allows the system to plot the book stock level against the gauge level in real-time so that any discrepancy is immediately apparent. Even when no one is looking at the data, the system may be set to raise e-mail or even text alerts if a sudden fall in tank stock is seen. The Fuel island terminal is constantly on guard for stock falls when there is no activity on the fuel pumps.

This site is almost perfect. The blue and green lines are virtually in the same place, and there is little discernible drift over three months in the red discrepancy line. The red peaks showing the time between the gauge seeing deliveries and them being entered are minimal, and the steady rate of fall means it is simple for the system to calculate when the stock will next need reordering.

The graph of Book Stock against Gauge stock should track each other perfectly. However, this site shows a problem over time with the pump over-delivering resulting in an increasing discrepancy (red bottom line). There also appear to be several step changes that may indicate incorrect data entry, short deliveries or even theft from the tanks.

Learn More about the Eclipse Fuel System
Learn More about the Jigsaw Fuel Web Service
Learn More about our Access Device options
Integrated Pump / Fuel options available