No one wants to return home from a trip to the grocery store to discover that instead of 128 ounces, the gallon of milk that was purchased contained only 125 ounces, or that the box of toaster pastries had only four instead of the customary six. In other words, everyone who buys something – from the most insignificant pack of chewing gum to the largest house – wants to get what he or she paid for.
The same theory holds true when considering fuel deliveries to retail or commercial fueling sites – if the fuel-site operator needs 7,000 gallons dropped into a UST, he wants 7,000 gallons dropped. Unfortunately, traditional analog delivery-monitoring systems could not always guarantee that the proper amount of fuel was dropped into the underground storage tank (UST), or that the trailer tank was empty when it actually wasn’t. When cases such as these arise, it is said that a fuel ‘retain’ condition has occurred.
In considering fuel retain and its potential negative effects for the supplier and fuel-site operator, there are three that are liable to occur most often:
1. Disputed delivery amount
If the bill of lading says a fuel delivery should consist of 7,000 gallons of gasoline or diesel, the fuel-site operator surely wants his 7,000 gallons. However, if the fuel-delivery company is using an analog tank-monitoring system on its fleet, a number of conditions can prevent that 7,000 gallons from actually being dropped, including 1) a fuel compartment that closes too early; 2) system air pressure interrupted or lost during unloading, resulting in premature valve closure; and 3) a trailer that is parked on an uneven surface, which can signal a ‘false positive’ that erroneously indicates that the fuel compartment has been completely drained into the UST.
What makes this error especially unique and catastrophically damaging is the potential toll it can take on the relationship between the fuel supplier and the end-user. No end-user will stomach errors in fuel-drop amounts and if they occur consistently, the fuel-site operator would be well within his rights to seek out a different, ostensibly more reliable fuel supplier.
2. Retain results in mixed product
The causes of this retain condition are the same as the three listed above, along with a hurried or distracted driver forgetting to unload a compartment on the trailer. A retain of this sort creates a cross-contamination risk where different types of fuel are mixed together in a delivery compartment.
The worst-case effect of a cross-contamination loading error is the shutdown of fueling services for several hours at the retail site since the fouled fuel will need to be removed from the UST, the storage tanks cleaned and a clean batch of fuel delivered. Anytime tanks need to be emptied, cleaned and refilled, the site operator incurs unplanned purchase and maintenance costs, as well as experiencing lost revenue due to the site being shut down. Additionally, before the retain-caused error is actually discovered, some of the bad fuel may make its way into the vehicles of customers, which can lead to damage to the fueling system that will negatively affect its ability to operate effectively and could lead to extensive repair costs.
3. An overfill condition occurs
This error occurs when a compartment on the delivery vehicle is not completely emptied due to, again, an unlevel delivery surface, premature closing of the fuel compartment or loss of air pressure during the unloading process. Product overfills are dangerous and costly for both the driver and the fueling site as they can, most significantly, create a fire hazard. Additionally, spilled fuel is not saleable, which affects the bottom line of the supplier and end-user, and some of the lost fuel – in extreme cases – can make its way into the environment where it can potentially affect groundwater supplies.
A common safeguard against a retain condition that can lead to an overfill is the use of retain probes in the delivery vehicle’s fuel compartments, but industry analysis and use patterns indicate that these probes are utilized on just 20 percent of the fuel trailers in the United States.
Eliminating the wrath of retain
With the need to deliver and receive the proper fuel amount being a paramount concern for both the fuel-delivery company and the fuel-site operator, every effort must be made to ensure that fuel-retain conditions do not manifest themselves at the conclusion of a fuel drop. While analog delivery-vehicle tank-monitoring systems have been the industry standard for many years, there are enough blind spots in their capabilities that they cannot be trusted to entirely prevent fuel-retain conditions from occurring.
With that in mind, digital tank-monitoring technology promises to be the next solution in this area. Through the use of a graphic touchscreen display, digital technology can wirelessly consolidate the driver’s access to the many different control systems on a fuel trailer – including fuel retain, overfill control, on-board monitoring, pneumatic (air pressure) control, product-crossover prevention, system troubleshooting and usage history. The digital system can also predict or prevent non-permissive readings, which lets the driver confidently know that the loading process will proceed uninterrupted. This will also help cut down on wait times, which is a huge added benefit for the fuel supplier and the site operator.
Once the digital system’s touchscreen is securely activated by the driver – even while wearing gloves – via a unique user ID and PIN it will only allow a delivery when the proper connection between the trailer and UST is identified. Loading will only begin if the driver has full permit status, meaning that all vapor connections, overfill components and grounding devices are safe and operational. The driver simply refers to RFID technology to know which product will be loaded into each compartment, with the system knowing, through its wireless-communication capabilities, if the correct fuel is going into the correct tank. This allows the correct compartment valve to open automatically, initiating the unloading process.
On the other hand, if an incorrect truck-to-UST connection is attempted, the digital system will prevent the trailer’s valves from opening and the delivery will be unable to commence. At the conclusion of the delivery process, which only ceases when each compartment is empty, the touchscreen will notify the driver that all hoses, elbows and adaptors can be safely disconnected and that all compartments are empty, making them ready to be refilled at the loading rack.
In addition to getting what they paid for, fuel-site operators also want their fuel deliveries to be safe and efficient. The retain conditions that can develop with the use of analog tank-monitoring systems can, at the least, put the safety and efficiency of the fuel-delivery process in jeopardy. However, fuel retains can now be well on their way to becoming extinct through an innovative new tank-monitoring system that prevents the conditions that can lead to fuel retain from occurring. This will lead to safer, more efficient delivery processes that will leave both the supplier and end-user confident that they have, indeed, gotten what they paid for.
Mark Dudley of Civacon, based in Hamilton, OH, has 15 years of experience in the fuel-transportation industry, including involvement in advancing fuel-delivery technology. Civacon is delivering what’s next through innovations designed to enhance safety, reliability, efficiency and business performance for the cargo-tank industry. One of Civacon’s latest innovations is the CivaCommand Smart Tank System, which is a highly engineered, easy-to-use digital tank-monitoring technology that features an easy-to-read graphic touchscreen display that communicates wirelessly with the trailer’s fuel-delivery and operation-monitoring components.