The filling tubes of a track are mounted next to each other in the filling tube sledge along the track axis. The filling tube sledge is mounted on rollers and enables the filling tubes to move transversely (+/- 100 mm) and longitudinally (approx. up to 10 m) via the hydraulic system. The transverse movement is driven by one or two hydraulic cylinders that are operated in parallel. The longitudinal movement is driven by a hydraulic motor. 

The movement commands for transverse and longitudinal movement can be given by operating the joystick in the control panel in the control room. The operating personnel can see the filling point through the windows of the operating room and can use the transverse and longitudinal movement to position the filling pipe selected for loading exactly over the dome opening. The end positions of the longitudinal and transverse movement and the center position of the transverse movement are detected by sensors.

The filling tubes are machine-made in a high-quality design. The weight of a filling tube is between 1,600 and 2,000 kg, depending on the design. The guide surfaces are hard chrome-plated and bronze-guided. The wall thicknesses of 10-20 mm, depending on the filling tube component, are designed for a very long service life. With regular maintenance, service lives of up to 35 years are possible.

To move in and out of the railcar, the filling tubes are equipped with an internal hydraulic cylinder with which the filling tube reaches an extension length of 4,250 mm (Western Europe), 4,700 mm (Eastern Europe) or in accordance with the country-specific tank car types. The end positions “filling tube up” and “filling tube retracted into tank car” are monitored with initiators.

In the upper end position, the filling tube has a mechanical lock.

The product is fed through the 200 to 300 mm inner diameter of the filling tube (standard filling tube 230 mm) and the product connection piece of the articulated swivel joints or telescopic tubes. The gas is returned through the filling tube and the vertical gas telescopic pipe via the product connection piece of the gas swivel joints or the gas telescopic pipe. The inflatable sealing bellows or sealing plate (Eastern European tank cars) attached to the filling tube allows the tank car to be hermetically sealed during loading. The filling tubes are equipped with overfill protection based on the bubble principle or with a special mechanical overfill protection probe and pressure monitoring.

All parts touching the railcar are made of bronze. The grounding of the railcars is achieved via grounding contacts on the filling tube when the filling tube is placed and monitored by a grounding test device (automatic grounding). If the railcar cannot be grounded by the automatic grounding, grounding can be established using the second grounding test device. Grounding monitoring for railcars is required on a country-specific basis. In Germany, for example, separate earthing monitoring for railcars is not necessary.

Further monitoring is carried out in the associated pneumatic cabinet and hydraulic cabinet.

The decision as to which system is used to connect the filling tube technology to the system side depends on the required movement range of the filling tubes. This movement range depends on the dimensions of different railcars to be loaded.

The gas return of the filling tube is connected to the gas return line via a gas swivel joint or gas telescopic tubes. The gas return is usually equipped with pneumatically controlled fittings with which the gas line can be shut off. Continuous pressure monitoring of the gas phase in the railcar and the gas line protects the steam system from impermissible over- or under-pressure.

The filling tubes are connected to the various product distributors via articulated swivel joints or telescopic pipes. The articulated swivel joints/telescopic pipes for product lines and gas lines enable the filling tube to move in the horizontal plane (left, right, forward and backward).

A hydraulic system is usually installed for each filling tube system. The hydraulic system (designed according to ATEX guidelines or country-specific Ex requirements) controls the filling tube mechanics. The hydraulic pressure required for the required hydraulic movement is provided by a hydraulic pump motor combination.

The hydraulic motor is only activated when hydraulic pressure is requested by appropriate functions. The following functions are provided:

• Selection Filling tube
• Filling tube upwards or downwards
• Filling tube sledge left or right
• Filling tube sledge forward or backward
• Filling tube over Hydraulic accumulator upwards
• Wastegate