4.
a. If the leakage rate is less than 0.05 i n. Hg (.17 kP a) in 24 hours, the machine is s uf fi-
ciently tight.
b. If the leakage rate exceed s 0.05 in. Hg (.17 kPa) in 24 hours, repressurize the vessel and
test for leaks. If refrig erant is available in th e other vessel, pressur i ze by following Steps
2-10 of Return Ref rigerant to Normal Op erating Conditions s ec t ion. If not, use nitrogen
and a refrigerant trace r. Raise the vessel press u re in increments unti l the leak is
detected. If refriger an t is used, the maximum ga s pressure is approxim at ely 120 psig
(827 kPa) for HCFC-22 , 70 psig (483 kPa) for HFC-134a at normal ambi ent temperature.
If nitrogen is used, limit the leak test pressur e to 230 psig (1585 kPa) maximu m.
5. Repair leak, retest , and proceed with dehyd r at ion.
Click here for Fig ure 27 — Typical Option al Pumpout System Pip ing Schematic with
Storage Tank
Click here for Fig ure 28 — Typical Option al Pumpout System Pip ing Schematic with-
out Storage T ank