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ES&H
Manual Fire Protection Supplement |
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Chapter 4: Fire Protection System Inspection, Testing,
and Maintenance Procedure |
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Appendix 4: Procedure for Testing Gas Detection Systems |
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1.0
Purpose
This document provides a procedure for conducting periodic testing of a fire-detection device required by NFPA 72 National Fire Alarm Code, 2010 Edition Table 14.4.2.2 Device 14(f) and Table 14.4.5 Component 15(g).
2.0
Scope
This test is to be performed annually on each gas detection system.
3.0 Planning
3.1 Notify the facility work coordinator using the approved electronic work control notification procedure. Allow one week for approval of the requested work and be prepared to reschedule the requested work to satisfy the areas production schedule.
3.2 Staff Required: 2
3.3 Time Required: 4 Hours
3.4 Equipment Required
· Manufacturer’s Manual (See ‘References’ section below.)
· Calibrated Thermometer
· Sensor Sample Cape
· Pressure Regulator, set to flow 1.5 liters per minute
· Isolation Valve
· Approx. 4 feet of ¼-inch I.D. Tygon tubing
· Calibrated Zero Span Gas
· Calibrated 50% LEL Methane Span Gas
4.0
Test Preparation
4.1
Establish the fire-detection system
impairment using the Fire
Protection Supplemental Chapter 5: Fire Protection System Impairment Procedure
for detailed instructions on work planning, advanced notification, and
administrative controls.
· Post the ‘Fire Alarm
Systems Testing in Progress’ notification signs.
4.2
Invite
the SOTR to witness the test.
4.3
Evacuate
hazard area of unnecessary personnel.
4.4
Station
a knowledgeable technician at the Fire Alarm Control Panel (FACP); disconnect
the building audible alarms at the FACP.
The knowledgeable technician is to remain attentive at the FACP at all
times that the audible alarms are disconnected.
· In the unlikely event that an unanticipated
fire alarm signal is received on the FACP, the technician must reconnect the
building audible devices and join the building evacuation.
5.0
Conduct the Test
5.1
Record the detector’s serial number and location on
the attached datasheet.
5.2
Make sure the instrument has been operating for a
minimum of thirty minutes prior to
performing a calibration.
5.3
Determine the ambient temperature in the sensor location.
· Temperature
should be between 50ºF and 90ºF.
· Calibration is
not accurate at temperatures below 50ºF.
· Record the
temperature and include it on the calibration certification.
5.4
Calibrate Zero Span.
· Use sections of the Tygon
tubing to make several connections.
· Connect the
outlet on the Zero Span gas valve to the isolation valve.
· Connect the isolation valve to the high-side of the
pressure regulator.
· Connect the
low-side of the pressure
regulator to the inlet marked on the sample cape.
5.5
Observe the inlet and outlet designations on the isolation valve.
5.6
Insert the gas sensor into the sample cape, as shown
in figure I.
5.7
Fully open the Zero
Span gas cylinder valve.
5.8
Fully open the isolation valve.
5.9
Wait approximately
15 seconds and, then, observe the VU meter indication.
· It is normal for the sensor to show a slight 'zero drift'
while in operation.
· If the indication
does not represent true zero, use the zero potentiometer located on the right-hand side of the controller to
adjust the zero baseline setting.
· Record the
initial and adjusted readings on the calibration certification.
5.10
Fully close the Zero Span gas cylinder valve.
5.11
Disconnect the
calibration tubing assembly from the cylinder outlet.
5.12
Adjust 50% Span.
5.13
Use sections of the Tygon tubing to make several connections.
· Connect the
outlet on the 50% LEL Methane Span gas valve to the isolation valve.
· Connect the
isolation valve to the high-side of the pressure regulator.
· Connect the
low-side of the pressure regulator to the inlet marked on the sample cape.
5.14
Observe the inlet and outlet
designations on the isolation valve.
5.15
Check
the VU meter.
· Insert the gas
sensor into the sample cape, as shown in figure I
· Fully open the 50% LEL Methane Span gas cylinder valve.
· Open the
isolation valve.
· Allow the
calibration gas to flow across the sensor for
approximately 15 seconds.
· Observe the VU
meter indication.
o
The meter should be stabilized between 47%
and 55%.
o
If
the reading is no more than 15%
outside of the high or low point of this range, adjust the Span potentiometer on the right side of
the controller to 50%.
· Repeat this procedure for each sensor to be tested.
5.16
If the indication is outside of the plus or minus
15% tolerance, or if you are unable to
set the Span to 50%, proceed to the troubleshooting section (section VIII) of the instrument
operational manual.
5.17
If the sensor is over 18
months old, it likely needs to be replaced. The catalytic bead sensor is an organic device, which deteriorates
over its operational life in proportion to
its exposure to gasses.
5.18
Fully close the 50% LEL Methane Span gas cylinder
valve.
5.19
Disconnect the
calibration tubing assembly from the cylinder outlet.
5.20
Replace all sensors
to their original locations.
5.21
After successful calibration, affix a current,
dated, calibration sticker to the controller
housing, and a corresponding color-coded dot to each sensor tested.
5.22
Check high and low alarm settings.
5.23
Operate the high and low alarm setpoint
switches to the left of the VU meter and verify alarms.
5.24
Verify the setpoints
against the factory settings for the original installation. These settings
should be recorded on the controller.
5.25
Record high and low alarm setpoints
on the calibration certification.
5.26
Observe the condition of each detector for signs of
mechanical damage, or anything that may obstruct the sampling process.
5.27
Document results on the attached data sheet.
6.0
System Restoration
6.1
Reconnect
the building audible alarms at
the gas alarm control panel.
6.2
Dismiss
assisting technician at the gas alarm control panel.
6.3
Remove
the ‘Fire Alarm Systems Testing in Progress’ notification signs previously
posted.
6.4
Notify
the SOTR that the tests are complete and system is on-line and
operational. Allow SOTR to verify that
the system is in normal operating condition.
6.5
Allow
personnel to return to the area previously designated as hazardous.
7.0
Conclusion
Upon completion of the procedure, the gas detection system is on-line and operational.
8.0
References
·
U.S.I's
Two-Stage Alarm Gas Detector 0 &
M manual; CALIBRATION and
MAINTENANCE Sections
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ISSUING
AUTHORITY |
APPENDIX
AUTHOR |
APPROVAL
DATE |
EXPIRATION
DATE |
REV. |
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Fire Protection Dept |
06/15/2011 |
06/15/2016 |
0 |
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