5-18. CHARGING THE SYSTEM (cont.).
a. Place the refrigerant cylinder on a scale of sufficient capacity.
Weigh the cylinder and record the weight.
Open the suction
service valve and slightly open the cylinder
shutoff valve. Gas refrigerant will be sucked into the refri-
geration system rapidly at first, then more slowly as pressures
begin to equalize.
When pressures have equalized or 10 pounds
(4.48 kg) of refrigerant gas have flowed into the refrigerant system,
close the suction service valve and the cylinder shutoff valve.
Check operation and top off refrigerant as necessary, in the
If knocking or pounding is heard when starting the air conditioner,
shut down at once and release some refrigerant before attempting
The vapor valve is not used on a two valve system.
If a one valve cylinder is used invert the cylinder.