4.
Purge system high side to low side.
The following procedures should utilize the following
MAXIMUM gas pressure:
• Leak Testing: 1030 to 1200 kPa, 10.3 to 12.0 bar, 150-175 psig,
• Purging/Dehydration: 70 to 140 kPa, 0.7 to 1.4 bar, 10-20 psig,
• Soldering: 35 kPa, 0.35 bar, 5 psig.
6-16
Using Pressurized Nitrogen
Refrigeration Maintenance and Service Operations
CRR-20 & CRR-40, September 1999
Using Pressurized Nitrogen
The improper use of high pressure cylinders can cause physi-
cal damage to components, or personal injury, or cause stress
that would lead to failure of components.
Safety Precautions
Observe the proper handling of cylinders:
1.
Always keep protective cap on cylinder when not in use.
2.
Secure cylinder in proper storage area or fastened to cart.
3.
DO NOT expose to excessive heat or direct sun light.
4.
DO NOT drop, dent, or damage cylinder.
5.
Use a pressure regulator and a safety pressure relief valve
as part of the pressure testing equipment. The safety pres-
sure relief valve should be of the non-adjustable, non-tem-
pering type. The valve should bypass any time the pres-
sure exceeds its setting.
6.
Open valve slowly; use regulators and safety valves that
are in good working order.
7.
The regulator should have two gauges; one to read tank
pressure, the other to read line pressure. Properly main-
tained equipment will allow leak testing, purging, or dehy-
dration to be done safely.
CAUTION: Nitrogen (N2 ) is under 15,170 kPa, 151.70
bar, 2200 psig, or greater. Pressure is for full cylin-
der at 21 C (70 F). DO NOT use Oxygen (O2), acety-
lene or any other types of pressurized gas on refrig-
eration systems or any component of a system.
Dehydration, pressure testing, purging and soldering can
be accomplished with the use of dry nitrogen (N2 ). The prop-
er equipment and application of equipment is of greatest
importance.
Procedure
1.
Attach gauge manifold set (refer to “Gauge Manifold Set
Attachment and Purging” for proper procedure for con-
necting to compressor).
2.
Close both hand valves on the gauge manifold (front seat-
ed).
3.
Connect charging hose to a source of nitrogen. Adjust
pressure regulator to the proper pressure for the required
procedure.
Typical Pressurized Gas Bottle with Pressure
Regulator and Gauges
1. Line Pressure
2. Tank Pressure
3. Tank
4. Pressure Test Line to System
5. Safety Valve
6. Pressure Regulator
Summary of Contents for CRR-20
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