Leak test
The system is filled up with Argon up to the following test pressures:
Upon veryfing that pressure has not dropped after 24h, the system is emptied
down to 0.05mbar using an oil free diaphragm vacuum pump (to avoid oil being
drawn into the piping). Upon veryfing that pressure has not risen after 24h, the
system is considered leak tight.
Cleaning
The cleaning will be done by flushing a solvent through the piping.
The
proposed solvent is Fomblin SV 90, a low
molecular weight perfluoropolyether manufactured by Ausimont.
An pumping unit with a liquid heater has been adapted for this purpose, allowing to select the solvent temperature.
The suggested solvent temperature is:
50 C for liquid input and vapour
return lines
30 C for the staves
Several pipes can be cleaned in parallel while ensuring a flow speed above 3 m/s in each pipe. The suggested flushing time is 6 hours.
Upon completion of cleaning, a vacuum pump will operate continuously for 24 h
in each line, in order to draw out all remains of solvent.