case study-iii boiler tube failure. the incident boiler make: miura date: march 26, 2010 place:...
TRANSCRIPT
CASE STUDY-IIIBOILER TUBE FAILURE
The Incident Boiler Make: MIURA Date: March 26, 2010 Place: At sea Initial Indication: Frequent water being taken
into hotwell indicating Boiler High Water Consumption and Boiler Feed pump running frequently
Boiler Furnace checked through peephole, found slight water accumulation inside the furnace
Confirmation: Boiler burner and swirler unit removed, found
few tubes on Stbd aft leaking and steam leaking in the form of a jet
Action: Main Engine and Boiler stopped, 6 Nos. leaky
tubes plugged by ship staff
Repeat of the Incident Date: April 11, 2010 Place: At Port Initial Indication: Frequent water being taken
into hot well indicating Boiler High Water Consumption and Boiler Feed pump running frequently
Boiler Furnace checked through peephole, found slight water accumulation inside the furnace
Confirmation: Boiler burner and swirler unit removed. Found 3 major tube leakages and 27 minor tube leakages and steam leaking in the form of a jet
Action: Boiler stopped. 30 Nos. leaky tubes plugged by ship staff
Immediate Causes Identified ROOT CAUSE: Failure to monitor Boiler water
condition
INDIRECT CAUSES:Failure to take proper rounds in
Engine RoomFailure in daily monitoring of
Cascade tank water quality, Failure in daily Monitoring of
Observation tank on Deck Failure to test Cargo tank heating
Coil at Regular intervals
Design problemsCascade tank was not fitted with Oil
Detecting Sensor or Salinity Sensor to warn operators
Poor material of Plate heaters --- Cracking of plate damages boiler water very fast & by the time, Duty Engineer realizes, Oily Water enters Boiler
Miura Boiler load might reach 100% at High Combustion Mode
Burner has O-rings which require renewal every year
Leaky Burner can cause Violent Combustion – leading to tube burn out
Operational & Maintenance Problems
Lack of interest to protect MachineryLack of motivation and complacency
by ship staffUn-Controlled Dumping of excess
Steam in Drain Cooler – leading to tube leakage
Burner never pressure tested “OR” Replaced every Year
Cargo Tank Heating Coil not tested at regular interval
Solutions Attached problem did not happen over-night
but over long period of time Daily Visual Check & Testing of
Cascade tank Water, observation tank and gauge glass will give indication
Beyond Doubt, C/E or none of the Duty Engrs or Oilers took regular thorough Rounds of Machinery Space
C/E to witness Boiler water test once every week
Please maintain firing of Boiler at Low Combustion mode, which is good enough for fulfilling Steam requirement onboard including cargo heating
Replacement of Burner every year on exchange basis
Burst water wall tubes in the furnace
Burst wall tubes and plugged tubes with color changed
Horizontal cracks were located in the water tubes of low area
Top view of the water tubes in the furnace room
Deposits in the burst tubes internally (Near bottom tube plate)
Water tubes internal viewing
Take care of your Boilers well!