Tyco Fire Protection Products ANSUL PS-1000, Operation And Maintenance Manual

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Checking Nitrogen Cylinder Pressures 1
Temperature Correction Chart
ANSUL
®
fire suppression systems use compressed nitrogen as the expellant for the suppressing agents.
The instructions covering proper inspection and maintenance of this equipment state the 23 ft
3
(0.65 m
3
),
55 ft
3
(1.56 m
3
), 110 ft
3
(3.11 m
3
), and 220 ft
3
(6.23 m
3
) nitrogen cylinders should be replaced with fully charged cylin-
ders if the pressure is less than 1500 psi (103.4 bar) at 70 °F (21 °C). However, the pressure in the nitrogen cylinder
varies with changes in temperature.
Accordingly, the chart below has been prepared to assist users of ANSUL equipment in determining that the cylinder
being checked contains enough nitrogen to furnish a recommended operating pressure.
NOTE:
Working pressure
shall not exceed pressure stamped on cylinder.
Examples:
1. The nitrogen cylinder on an ANSUL fire suppression system indicates a pressure of 1450 psi (100 bar) on the
pressure gauge. The temperature of the cylinder is 40 °F (4 °C). Reference to the chart shows that this is above
the “temperature correction line” and the cylinder does not need to be replaced.
2. One of the nitrogen cylinders of an ANSUL fire suppression system indicates a pressure of 1350 psi
(93 bar) on the pressure gauge. The temperature of the cylinder is 80 °F (27 °C). Reference to the chart shows
that this is below the minimum recommended pressure for this temperature. The cylinder should be replaced by
a fully charged nitrogen cylinder.
Note: The metric values in this document are provided for dimensional reference only and do not reflect an actual measurement.
ANSUL, and the product names listed in this material are marks and/or registered trademarks. Unauthorized use is strictly prohibited.
CYLINDER
PRESSURE
(bar) psi
(124.1) 1800
(117.2) 1700
(110.3) 1600
(103.4) 1500
(96.5) 1400
(89.6) 1300
(82.7) 1200
(75.8) 1100
–65 –40 –20 0 20 40 60 80 100 120 130 °F
(–54) (–40) (–29) (–18) (–7) (4) (16) (27) (38) (49) (54) (°C)
NITROGEN CYLINDER TEMPERATURE
TEMPERATURE CORRECTION LINE
RECOMMENDED
PRESSURE
OPERATING