Filling and discharging of rail tank-wagons for liquids

Four standardised checklists help to avoid leaks from tank-wagons for liquids which mostly occur by incorrect filling or discharging processes.

• checking that closing devices are leakproof once the tank has been filled (“filler”, see RID 1.4.3.3 [= Regulations concerning the International Carriage of Dangerous Goods by Rail]), and
• ensuring after the tank has been unloaded that the valves and inspection openings are closed (“unloader”, see RID 1.4.3.7.1).

• be filled from the bottom through the bottom valve in conjunction with the external shut-off device (discharge valve, dry coupling) or filled from the top through the filling pipe or dome cover;
• discharged through the bottom shut-off device (discharge valve, dry coupling) or from the top through an attached dip tube.

• top filling
• top discharge
• bottom filling
• bottom discharge

As the most frequent cause of leaks is incorrect filling or discharge processes, the main aim behind these standardised checklists is to avoid leaks from tank-wagons for liquids by means of correct and professional handling on the part of operating staff working for fillers and unloaders (note: tank-wagons for pressurised gases are not dealt with here). They include the necessary steps (checkpoints) in the procedure to ensure leakproofness in the appropriate sequence which normally have to be observed when filling or emptying liquids into or from tank-wagons. They may need to be supplemented by the user for other specific operational steps/procedures (operating instructions).

The translation of the original German version into English has been made by the Intergovernmental Organisation for International Carriage by Rail (OTIF)

The four checklists are integrated into the so-called "Langfassung" (full version of this document) in the download sector at the top of this page.