Not that anyone expected there to be any leaks but it is always best to be sure! ATV Control Centre update on the ATV-5 refuelling operations from Marcus de Deus Silva:
The ATV-5 Refuelling System Leak Check just took place and was completely successful. This operation was the second part of ATV’s refuelling sequence. The main part of the leak check consisted of injecting helium gas into the pipes used to transfer liquid propellant from ATV-5 to the International Space Station’s Russian Service Module. Once the pipes were pressurised, the valves were commanded to close to isolate the system.
Experts at ATV’s Control Centre in Toulouse, France, then monitored the pressure and temperature in the pressurised lines for about 4 hours. No leak was detected so the ATV refuelling system is now ready for its next step which is tank pressurisation. This will take place next week on Tuesday 23rd September.