b. If the machine fails this test, check for large leaks (Step 2b).
c. Dehydrate the machine if it passes the standing v acuum test. Follow the pr ocedure in the
Machine Dehydration s ec t ion. Charge machine wi th refrigerant (see Pum po ut and
Refrigerant Transfer Procedures, Machines with Storage Tanks section, Steps 1a-e).
7. If a leak is found, pump th e r ef rigerant back into the stor a ge tank, or if isolation v al ves are
present, pump into the non-leaking vessel (s ee P um p out and Refrigerant Tra nsfer
Procedures section).
8. Transfer the refrig erant until machine pre ssure is at 18 in. Hg (40 kPa abso lute).
9. Repair the leak and repe at the procedure, beginn ing from Step 2h to ensure a le aktight
repair. (If machine is op ened to the atmosphere fo r an extended period, eva cuate it before
repeating leak test. )
Standing Vacuum Test
When performing the stan ding vacuum test, or mach ine dehydration, use a ma nom e ter or a
wet bulb indicator. Dial gages cannot indicate the sma ll amount of acceptable leaka ge during a
short period of time.
1. Attach an abs olute pressure ma nometer or wet bulb indicator to the machin e.
2. Evacuate the vessel (see Pumpout and Refrigerant Transfer Procedures section) to at least
18 in. Hg vac, ref 30-in. bar ( 41 kPa), using a vacuum pump or the pumpout unit.
3. Valve off the pump to hold the vacuum an d record the ma nometer or indi cator reading.