WHAT IS A BOILER LOG:

A Boiler Log is a check-list for the Boiler Operators. It helps to track the operating parameters over a period. For any Boiler Preventive Maintenance the Boiler log is a key factor. Separate log sheets are required for each Boiler in the plant. One option is having a log sheet that is valid for one month (31 days), and has provision for two sets of readings per day  for low and medium pressure boiler and three sets of reading per for high pressure boilers. It is recommended that completed logs should be properly preserves for future analysis.  

THE NEED FOR A BOILER LOG:

It helps to avoid an emergency shut-down. Over a period of time, by following operating trends from the boiler log, one can properly diagnose the problems and fix up a suitable system maintenance schedule. 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 preventive measure can be taken before it is necessary to shut the unit down for cleaning.

THE ROLE OF BOILER LOG IN REDUCING ACCIDENTS:

The majority of the Boiler accidents occur mainly due to two reasons; control failure and human operational / maintenance mistakes. The National Board Incident Report  for 1993 indicates that 79% of all reported boiler accidents for the three boiler categories occur due to either low water cut-offs, or operator error/poor maintenance. Low-water-cutoff problems account for 62% of the incidents. Therefore proper maintenance and testing of the control device could cause a dramatic reduction in the boiler accidents. Moreover proper keeping and analysis of boiler logs help operators to avoid operational/maintenance error and therefore reduce boiler accidents. Data in the log should be compared with data recorded when the boiler was new or recently overhauled. If such a comparison reveals significance deviation, technician may need to inspect and repair components.

MANAGEMENT'S  RESPONSIBILITY:        

The most important concern is to keep the log completely, accurately and updated regularly. It is not uncommon to find that logs are kept with identical headings for an entire month or with gaps in the readings. The management must stress the need for complete, accurate logs. And must also explains the need for analysis and its benefits. The management is responsible for implementing log program and supervising its continuous completion and ensuring that an analysis program is carried out from time to time.

CHECK LIST TO BE COVERED IN A BOILER LOG:

Log sheets are available from boiler insurance companies. Maintenance log should include those items recommended in the boiler and burner manufacture's operating instructions. It is always advisable to prepare customized log form. These log can be easily customized for the particular installation and its unique requirements. Suggested items that might be included in maintenance log are shown below. But items may be added or deleted as needed for the specific installation. It is advisable to maintain two Log Sheets to filled up by the control room and field operators separately.

SUGGESTED DAILY BOILER LOG PROGRAM:  

Daily Instrument Reading:

GENERAL:

*      Air Compressor Control pressure

*      Raw water supply pressure

BOILER:

*      No of Boiler (s) in service

*      Type of fuel

*      Operating time

*      Operating cycles

*      Amount of fuel on hand

*      Boiler water level ( normal, low, high )

*      Rate of firing level

*      Observation of Flame Condition

*      Boiler Water temperature

*      Stack temperature net

GAS FUEL:

*      Pilot gas pressure

*      Burner gas pressure

OIL FUEL:

*      No of oil pump in service

*      Vacuum pressure at pump

*      Oil pressure at pump

*      Oil pressure at burner

*      Oil pressure at regulating valve

*      Atomizing medium pressure, air, steam.

CONDENSATE SYSTEM  (steam boiler):

*      No of Boiler feed pump in service

*      Condensate return temperature

*      Level of water in condensate tank ( normal, low, high )

*      Make up water rate

FORCED HOT WATER CIRCULATING SYSTEM:

*      No of circulating pumps in service

*      Supply water temperature

*      Return water temperature

*      Level of water in expansion tank  ( normal, high, low )

BOILER WATER TREATMENT:

*      Treatment pump in service ( low, normal )

*      Level of chemicals in treatment tank

*      No of boiler water sample taken

MAINTENANCE OR REPAIR OPERATIONS

DAILY

*      Blow down and low water cutoff test of steam  boilers

*      Blow down gage glasses (steam)

*      Blow down make up feeder ( low pressure steam )

*      Blow down boiler ( steam )

*      Boiler control linkage check

*      Boiler and system leakage check

*      Burner flame check

WEEKLY