William H. Axtman
President of Gray Gull Associates, Inc.
Retired executive director of the American Boiler Manufacturers Association
Summary: The following article is a part of National Board
Classic Series and it was published in the National Board BULLETIN. (3 printed pages)
Often overlooked in boiler operation is the establishment and enforcement of a
procedure for keeping adequate boiler logs. The management of a facility which
has a boiler plant bears the responsibility for implementing and maintaining
Over a period of time, boiler operating logs help distinguish operating trends
that can allow problems to be diagnosed, and boiler and/or fuel-burning system
maintenance to be scheduled, before an emergency shutdown is necessary. For
example, a steady rise in stack temperature, at the same boiler load, indicates
dirty boiler firesides or water side scale build-up. In either case remedial
action can be taken before it is necessary to shut the unit down for cleaning.
There are two types of boiler logs: one for daily operations, the other for
maintenance activities. These logs can be easily customized for the particular
installation and its unique requirements. Using a computer or a word processor,
it is a relatively simple matter to prepare a customized log form. Items which
might be included are shown in the guidelines below. This material is by no
means inclusive; items may be added or deleted as needed for the specific
Log sheets are also available from boiler insurance companies. Maintenance logs
should include those items recommended in the boiler and burner manufacturer's
WHAT LOGS CAN TELL YOU
The National Board Incident Report
for 1993 indicates that 79 percent of all reported boiler accidents for the
three boiler categories are attributable to just two causes: low water cutoffs,
and operator error/poor maintenance. Proper keeping and analysis of boiler logs
help operators to focus on these areas, and therefore reduce boiler accidents.
As low-water-cutoff problems account for 62 percent of the incidents,
maintenance and testing of these devices could cause a dramatic reduction in
A separate log sheet is required for each boiler in the facility. One option is
having a log sheet that is good for one month (31 days), and provides for two
sets of readings per day. It is recommended that completed logs be three-hole
punched and filed in a loose-leaf notebook for future analysis. Management
should establish a reasonable period of time for log retention, consistent with
the life expectancy of the unit.
Make provisions on the sheets for recording weekly and monthly checks with the
date of completion. A general comments section allows significant events, such
as the date of the annual boiler inspection, to be recorded. Other events such
as boiler malfunctions should also be noted.
Logs for high-pressure boilers are similar, but provide for at least three
readings (one per shift) per day. High-pressure logs normally require
additional readings consistent with the system.
Items which might be considered for a customized log are shown below. The most
important concern is to keep the log completely, accurately, and updated
regularly. Too often, logs are kept with identical readings for an entire month
or with gaps in the readings. Management must stress the need for complete,
accurate logs, and must also explain the need for analysis and its benefits.
Suggested items which might be included in a maintenance log are shown below.
- Operator --
Responsible for taking boiler readings, assuring accuracy and initial analysis.
- Management --
Responsible for implementing log program and supervising its continuous
completion. Also responsible for ensuring that an analysis program is carried
- Retention --
All persons involved must assure logs are retained in accordance with the
- Analysis --
All involved persons must examine logs to determine trends and then act upon or
recommend action in response to these trends. Repair or replacement of
equipment, as indicated by these operation or maintenance log indications, must
be performed as needed.
A well thought-out operation and maintenance log program designed to address
the requirements of the facility will reduce boiler accidents, downtime, and
equipment loss. Such a program, properly carried out, will focus attention of
both management and operating personnel on the often-overlooked boiler plant,
thereby addressing small problems before they become large ones.
SUGGESTED DAILY BOILER LOG PROGRAM
SUGGESTED MAINTENANCE LOG PROGRAM
Editor's note: Some ASME Boiler and Pressure Vessel Code requirements may have changed because of advances in material technology and/or actual experience. The reader is cautioned to refer to the latest edition and addenda of the ASME Boiler and Pressure Vessel Code for current requirements.