Transcript Boiler Tube Failure Case Study

CASE STUDY-III
BOILER 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
Room
Failure 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 problems
 Cascade 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 Machinery
Lack of motivation and complacency by
ship staff
Un-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!