24 July 2003
including Change 1, Jan 2004 and Change 2, March 2005
and timing with respect to pre-purge, ignition, pilot proving, flame proving, and post-
purge periods. Check the operation of flame failure and combustion air failure devices
to ensure that they properly shut off the supply of fuel; this should be done by simulating
a flame failure (by manually shutting off the fuel or by other means) and by observing
the operation of the controls, solenoid valves, diaphragm operated valves and so forth,
which are to operate during a flame failure. The installation of the boiler and controls
including the fuel train and the operation of automatic burner management systems
must comply with the National Fire Codes (NFC), including NFPA 85, Boiler and
Combustible Systems Hazards Code; and ASME CSD-1 in effect at the time of
installation of the boiler. Inspect feedwater controls, and check the ability of the controls
to maintain proper water level throughout the range of capacity with load swings. Check
the operation of the low-water fuel cutoff and automatic water feeding devices by
draining the float bowl, lowering the boiler water level, and performing the necessary
steps to cause these devices to function to ensure that they operate properly.
PIPING AND PIPING CONNECTIONS. While the boiler (or vessel) is
operating, examine all steam and water pipes, including connections to the water
columns and all associated piping, for leaks. If any leaks are found, determine whether
they are the result of excessive strains due to expansion, contraction, water hammer, or
other causes. Look for undue vibration, particularly in piping connections to the boiler
and the vessel. Where excessive vibration is found, examine connections and parts for
a tendency to crystallize.
Temperature Indicating Devices. Observe all temperature indicating
devices for indications of excessive temperatures, particularly during and immediately
following the time when high load demands are made on the boiler and the vessel.
Metering and Recording Devices. While the boiler is operating under
normal conditions, observe the operation of all metering and recording devices. When
there is evidence that any such device is not functioning properly, it must be adjusted,
repaired, or replaced as necessary.
Blow-Down Valves. Test the freedom of each blow-down valve and its
connections by opening the valve and blowing down the boiler for a few seconds.
Determine whether the valve is excessively worn or otherwise defective, and whether
there is evidence of restrictions in the valve or connected piping preventing proper blow-
down of the boiler.
Stop and Check Valves. While the boiler (or vessel) is operating, inspect
the operating condition of each stop and check valve where possible. Serious defects
of externally controlled stop valves may be detected by operating the valve when it is
under pressure. Similarly, defects in check valves may be detected by listening to the