One of the most important tasks for drivers who deliver motor fuels to filling stations is to get the right product in the right quantity into the right tank – every time. If there is a failure in any one of these conditions, it can lead to retained product in one of the cargo tank trailer’s compartments. That’s why cargo tank component companies and cargo tank builders have developed equipment and systems that can indicate, alert and prohibit loading if any product is retained, helping resolve potential negative outcomes.
When a retained-product condition does occur, it will usually result in one of three common outcomes:
- Improper Delivery Amount: Prior to making a fuel delivery, the transport driver must know how much space is available in each UST. First, if possible, the driver will get an up-to-date inventory level for each UST from the site’s electronic inventory system. The driver will then compare these readings to the amount of fuel to be dropped (noted on the bill of lading). Second, drivers are generally required to manually “stick” each UST to measure the product level and compare these measurements to the tank’s strapping charts and re-confirm that space is available for the delivery. These stick readings are usually recorded on the delivery report as a delivery specific record that can be referred to if a delivery discrepancy claim is made by the fuel recipient. Once the delivery begins, there are basic steps that a driver can take to help prevent a retain occurrence. Checking for hose vibration or consulting the sight glass on the delivery elbow are ways of detecting that all product has been dropped, and that no product remains in the hose or in the trailer compartment. However, these steps are not fail-safe. If the trailer is equipped with an onboard monitor, the monitor’s retained LED lights can be checked to see if product remains in any of the compartments. Unfortunately, these analog-based systems can at times indicate incorrectly.
Mixed Product: A retained fuel event on a trailer that is missed and has different product loaded with it at a loading terminal can result in mixed product arriving at a retail site. Unknowingly delivering this mixed product into fuel storage tanks can have serious effects. The resulting fuel cross-contamination in the site’s storage tanks may lead to the shutdown of fueling services while the fouled fuel is pumped out and a new load of fuel is delivered. There are also varying levels of concerns and costs when a retain caused cross-drop occurs. A diesel-into-gasoline cross-drop can clog vehicle fuel filters, which may then need to be cleaned or replaced. The contaminated fuel will also need to be pumped out of the UST and replaced. When a gasoline mix is delivered into a diesel UST, the engine of the diesel vehicle that receives the contaminated fuel may become permanently damaged.
- Overfill Condition: Back at the terminal, a product retain resulting from a trailer compartment that is not completely emptied can easily turn into an overfill condition. Product overfill incidents generally result in an immediate and abrupt shutdown of the trailer’s loading process until it can be investigated, and the root cause is determined. If this situation is not properly controlled, it can lead to product overfill into the trailer’s vapor-recovery piping or a spill incident, which can be hazardous to people and the environment.
To help combat the occurrence of retained-fuel conditions and potential negative outcomes, Civacon, a product brand of OPW, has designed, engineered and developed the CivaCommand Smart Tank System. The highlight of CivaCommand is its user-friendly digital cargo tank-control technology that features an easy-to-read graphic touchscreen display that is in direct digital communication with the trailer’s various fuel-delivery and operation-control components. The touchscreen display consolidates access to the many different control aspects on a cargo tank, including product-retain monitoring, overfill detection and control, pneumatic (air pressure) monitoring, product-crossover prevention, system troubleshooting and usage/event history. This digital technology enables the system to more accurately and securely detect retained product through the use of patented fluid-property sensors installed on the tanker’s product loading and unloading adaptor.
For more information on Civacon’s new CivaCommand Smart Tank System, please visit civacon.com.