Thermo King 098916, Maintenance Manual

Page: 136 / 196

Refrigeration Maintenance
135
Safety Precautions
Observe the proper handling of cylinders:
• Always keep protective cap on cylinder when
not in use.
• Secure cylinder in proper storage area or
fastened to cart.
• Do not expose to excessive heat or direct sun
light.
• Do not drop, dent, or damage cylinder.
• Use a pressure regulator and a safety pressure
relief valve as part of the pressure testing
equipment. The safety pressure relief valve
should be of the non-adjustable,
non-tempering type. The valve should bypass
any time the pressure exceeds its setting.
• Open valve slowly; use regulators and safety
valves that are in good working order.
• The regulator should have two gauges; one to
read tank pressure, the other to read line
pressure. Properly maintained equipment will
allow leak testing, purging, or dehydration to
be done safely.
Dehydration, pressure testing, purging and
soldering can be accomplished with the use of dry
nitrogen (N
2
). The proper equipment and
application of equipment is of greatest
importance.
Purge High Side to Low Side
1. Attach gauge manifold set (see “Gauge
Manifold Set Attachment and Purging” for
proper procedure for connecting to
compressor).
2. Close both hand valves on the gauge manifold
(front seated).
3. Connect charging hose to a source of nitrogen.
Adjust pressure regulator to the proper
pressure for the required procedure.
4. Purge system high side to low side.
Maximum Gas Pressures
The following procedures should utilize the
following maximum gas pressure:
• Leak Testing: 1034 to 1200 kPa, 10.34 to
12.00 bar, 150-174 psig,
• Purging/Dehydration: 69 to 138 kPa, 0.69 to
1.38 bar, 10-20 psig,
• Soldering: 35 kPa, 0.35 bar, 5 psig.
CAUTION: Nitrogen (N
2
) is under
15,170 kPa, 151.70 bar, 2200 psig, or
greater. Pressure is for full cylinder at
21 C (70 F). DO NOT use Oxygen (O
2
),
acetylene or any other types of pressurized
gas on refrigeration systems or any
component of a system.