Customer application 25 July 2018
Well Equipped for Hazardous Areas

Tankers at airports around the world have to bring their A game every day. Closely timed flight schedules and strict safety regulations determine the everyday workload for vehicles and drivers. The Brazilian firm Rucker specializes in the equipping of airplane tanker trucks, and just completed a large project for Infraero, Brazil's national airline.

At most large airports, passenger and cargo planes are supplied using underground jet fuel pipelines. An Airbus A380, for example, can take on up to 310,000 liters of fuel, while an average tanker truck can only hold 40,000 liters. Fueling from tankers would obviously take a long time, which is why airports employ so-called hydrant dispensing trucks. They pump the jet fuel from the pipelines to the planes. In addition to enormous savings in time, this method also reduces the risks associated with mobile jet fuel tanks. It looks easy when the specially-trained airplane fuelers expertly connect hoses and control the fueling using remote control; however, this simplicity cloaks a complex technical system. Among other functions, the tankers remove the fuel from the underground pipelines, which are pressurized to 10 bar, and reduce the pressure to 3.5 bar. If the pressure is too high, then the tanks in the wings of the plane could be damaged. Hydrant dispensing tankers can start, monitor, and end the entire fueling process. Rucker provides the automation and regulation technology for these demanding applications.

Here’s How WAGO Supports You in the Ex Area:

The WAGO 750 XTR I/O-SYSTEM for Ex area applications withstands even the most extreme conditions.
The permissible surrounding air temperature range of −40°C to +70°C (−40°F ... +158°F) enables the modules to be used in any climatic zone without the need for additional protection from air-conditioning or heating systems.
The increased immunity to impulse voltages and interference even permit it to be used in medium-voltage systems.
Their extreme vibration and shock resistance satisfy even the requirements for rail vehicles and installation on marine diesel engines.

Converting to PLCs and Spring Pressure Connection Technology

Over the course of modernizing their tanker fleet, the Brazilian airline Infraero entrusted Rucker with the design and implementation of a solution for monitoring the operating logic. This system was to be equipped with a PLC and I/O modules for signal detection, and installed in a control cabinet in the cab of the tankers. The engineers at Rucker had wanted to convert the old tanker systems from relay controls to PLC technology for a long time. “A first attempt was implemented using screw systems; however, that did not lead to satisfying results. The dynamics in the tankers were problematic due to the constant movement and changes in the surrounding air temperatures. Vehicles would simply halt due to faulty contacts, which made the whole system unreliable,” reports Rafael Mendes, CEO of Rucker.

Heightened Requirements for Airport Applications

To solve the current problems, Rucker relied on spring clamping connection technology from Planen Automação, a WAGO sales partner based in São Paulo, to provide a complete solution based on controllers and I/O modules for hazardous areas. These could be installed, together with standard I/O modules, on one bus, which made the previous requirement of intrinsic barriers superfluous. The concept was specifically adapted to the increased demands for use at airports, in particular interactions with hazardous atmospheres. The greatest obstacle, however, lay in certifying the components.

Certification According to Brazilian Standards

Infraero required that one of the certifications for hazardous zones be carried out by the National Institute of Metrology, Standardization, and Industrial Quality, INMETRO. Planen Automação initiated the processes necessary to obtain the national certification from the TÜV certification association in Brazil. An approval procedure for the aggregate products was also be launched in connection with this. Support was provided by WAGO Minden, by specialists in these types of certification processes.

Easy Installation and Clearer Visibility

After the formalities were finally concluded, project implementation could begin. Rucker was able to reduce the size of the control cabinet due to the intrinsically safe Ex i modules, which share the same software for programming and communication as other modules. Prior to the WAGO solution, the company mounted the Ex i barrier separately from the controllers, which required one software package for programing the barrier, and another for the controllers. The compact modules enable optimal arrangement in the control cabinet, leading to easier assembly and better transparency.

Control Communication via ETHERNET Cable

Since the modules have spring clamping connections, the assembly was both faster, and the connections are more reliable. The easily accessible control communication via ETHERNET cables is another advantage of the current system. Previously, separate communication cables were required for the controllers and Ex i barrier. The focus in the new systems is primarily on fast and easy adjustments and optimizing of parameters, and the ability to add functions on site as per customer request. In addition, the user-friendly software and ETHERNET communication cable improve technical support by adding remote support via the Internet.

Milestones for WAGO Products in Brazil

From four original tanker trucks that were equipped with the WAGO kit in 2014, the fleet has grown, from 14 in 2016 through 21 in 2015 to the current 39 WAGO-equipped vehicles. Each system configuration includes a 750-881 PLC, digital input/output cards for 24 V, and Ex i digital input/output modules. The package also includes other I/O modules and relays from WAGO. Rucker's tankers now include almost 9,200 WAGO products for connection, automation, interfaces, and identification. “Now we can rely on a failure-free system, that can be maintained easily and even remotely by our technicians, including software upgrades,” states Mendes happily. Since the implementation of the project for Rucker, WAGO remains among the few manufacturers of controllers and I/O modules whose entire product portfolio is certified for hazardous zones by INMETRO.

Text: Rodrigo Rodrigues | WAGO Brazil

Photo: WAGO