Cryomech LNP-40, Инструкция по установке, эксплуатации и текущему обслуживанию

Страница: 93 / 102

Routine Maintenance
8-6
Figure 8-4: Close up of vacuum/charging manifold and pump
7) Evacuate to 50 microns.
8) Isolate the vacuum pump and add 50 PSIG (3.4 bar) of helium.
9) Vent the helium and repeat steps 7 & 8 at least once. Vent the helium and continue
to step 10.
10) Final evacuation should be to 25 microns.
11) Pressurize the line to the service access with the desired amount of helium pressure.
12) Slowly open the service valve to add helium to the system. The final helium charge in
the system is specified in Section 5.
CAUTION
No more than 5 PSIG (.34 bar) of gas should be added per minute to prevent internal
oil contamination to the system. If such contamination occurs, factory service will be
required.
13) After adding the helium, close the service valve and remove the service Aeroquip
®
from the service access.
Service
Aeroquips
Line to Helium
Tank
Vacuum
Sending Unit
Vacuum Valve
Charging Lines
Vent Valve
Relief Valve
11Jan10