How Boiler Survey on Ships Work

Internal surveys are required for all boilers, economizers, steam receivers, steam heated steam generators, thermal oil and hot water units intended for essential services, as well as boilers used exclusively for non-essential services with a working pressure greater than 0.35 MPa and a heating surface greater than 4.5 m2. Each of the five Special Survey cycles must include at least two internal examinations. Except in exceptional circumstances, the time between two such examinations cannot exceed 36 months.

 

During the Annual Survey, a general external examination will be conducted. An external survey of boilers, including tests of safety and protective devices, as well as tests of safety valves using their relieving gear, is to be performed annually within the range dates of the ship’s Annual Survey.

 

The safety valves for exhaust gas heated economizers must be tested at sea by the Chief Engineer within the range dates of the Annual Survey. Before crediting the Annual Survey, this test must be recorded in the log book and reviewed by the attending Surveyor.

General Requirements (Boiler Repair Spare Parts)

Auxiliary boiler surveys include ancillary equipment, which, along with the controls, should be examined under operating conditions and the correct adjustment of any safety devices verified.

 

• The boilers will be thoroughly inspected from the outside. The boiler supports, chocks, rolling stays, uptakes, and funnel base must all be in good working order.

 

• Thorough examination of each boiler, including its superheater, superheat control, air heater, and economiser, if fitted. If a boiler has not been sufficiently cleaned to allow a proper examination of pressure parts, the survey cannot be considered complete until this is done.

 

• Where the design of a boiler precludes direct visual internal examination of the shell, drums, or headers, the attending Surveyor(s) must be satisfied that the boiler is in a safe working condition by using remote viewing instruments, Ultrasonic Testing (UT), or hydraulic testing to determine a safe working pressure.

 

• Longitudinal stays connected to end plates by external and internal welds should be checked for cracking at the inner welds. All such stays should have ‘tell-tale’ holes drilled at the ends, 5 mm in diameter and deep enough to penetrate the centre of the stay beyond the inner weld.

 

• Prior to departure, every effort will be made to complete the survey. If the survey is not completed for any reason, the Owner/clear Operator’s intentions regarding completion must be ascertained.

 

• If a ship remains in port for more than two months after the date of the internal examination, a further internal survey is required.

 

• Rolling stays, expansion/sliding foot arrangements, and freedom of pins and holding down bolts must be specifically examined in the manner of attachments to the shell or casings, and pin freedom must be verified.

 

General Requirements  (Exhaust Gas Economizer)

 

• The survey cannot be considered complete until an exhaust gas economiser has been sufficiently cleaned to allow a proper examination of pressure parts.

 

• Where the design of an exhaust gas economiser precludes direct visual internal examination of the headers, the attending Surveyor(s) must be satisfied that the exhaust gas economiser is in a safe working condition by using remote viewing instruments, Ultrasonic Testing (UT), or hydraulic testing to determine a safe working pressure.

 

• The mountings (including all valves, fittings, burner units, drains, and filling valves) must be opened for internal inspection and, if necessary, rectification. The attending Surveyor(s) must ensure that all mountings are securely fastened and that any insulation that prevents full examination of studs and nuts is removed. Stub piece welds should be examined in terms of attachment to the shell, shell plating in terms of nozzles penetrating the shell (feed, etc.), and pads attached to the shell should be carefully examined for weld cracks.

 

• All pressure gauge connections must be free of obstructions, and their shut-off fittings must be clearly and correctly marked to indicate when they are in the open position.
• Exhaust gas economisers should be subjected to a thorough external inspection. It is necessary to ensure that the exhaust gas economiser supports, rolling stays, and uptakes are in good condition. Rolling stays, expansion/sliding foot arrangements, and freedom of pins and holding down bolts must be specifically examined in the manner of attachments to the shell or casings, and pin freedom must be verified.

General Requirements (Safety Valves)

• Under steam, safety valves must be adjusted to no more than 103% of the approved design pressure shown in the Register Book and Survey Preparation Package (SPP). A record of the pressure to which the safety valves have been set should be kept on board in all cases.

 

• If more than one safety valve is used, the other(s) must be gagged (not allowed to open) while the safety valve is tested. After completion, this role will be reversed so that all valves have been tested.

 

• Calibration of boiler pressure gauges.

 

• Examine the drain lines fitted to the safety valves when surveying Main and Boiler Repair Spare Parts, Auxiliary Boilers, Exhaust Gas Boilers, Economisers, or any steam plant to ensure they are independent, clear, unblocked, and in accordance with the appropriate Rules and Regulations.

 

General Requirements (Alarms)

 

• Periodic inspections of alarms, controls, and safeguards lights are required by the relevant Rules and Regulations. The goal of this survey is to ensure that all alarms, controls, and safeguards are still operational.

 

• At the due date, the survey of attended machinery space alarms, controls, and safeguards required for vessels/installations assigned the LMC (Lloyd’s Machinery Certificate) notation must be performed in conjunction with the associated machinery item.

 

• Changes to the hardware and software used for controlling and monitoring systems for propelling and essential auxiliary machinery since the original issue (and their identification) must be reviewed.

 

• The alarms, controls, and safeguards must function properly.

 

Examination under operating conditions is an important part of a boiler survey and will include the following:

 

1. Using a methodical blowdown sequence to ensure that water level indicators are functioning properly.
2. All safety and alarm equipment is tested.
3. Examination of boiler starting and firing sequences.

 

A general inspection of the associated oil fuel system, including fuel tank valves, pipes, and deck control gear, is also required.

General Requirements (Alarms, Level Devices, and Fuel Cut-Off Tests)

 

The following items will be examined under operating conditions:

 

• Calibration of the boiler pressure gauges. Where the calibration cannot be easily verified, a written statement from the Master/Chief Engineer confirming that the gauges have been calibrated is required. Alternatively, a second gauge for verification of the primary gauge could be considered.
• All safety and alarm equipment was tested, and boiler starting sequences and firing were observed.
• A general inspection of the associated oil fuel system, including fuel tank valves, pipes, and deck control gear, is also required.

General Requirements (Internal Inspection, Including Door Fit)

 

• Internal Boiler Inspection
• Manhole, mudhole, and handhole door joints must be examined to ensure that the jointing faces are in good condition and that the clearance at the spigot does not exceed 1.5 mm in any location.

General Requirements (Except For Steam Stop Valves, Valves And Mounting)

 

• The mountings (including all valves, burner units, fittings, drains, and filling valves) must be opened for internal inspection and, if necessary, rectification. Verify that all mountings are securely fastened and that any insulation that prevents full examination of studs and nuts is removed. Stub piece welds must be examined in terms of shell attachment.

 

• Shell plating in the form of nozzles penetrating the shell (feed, gauge glasses, etc.) and pads attached to the shell must be thoroughly examined for cracks that may be caused by welds.

 

• Welded connections of stub pipes to integral steam piping, particularly superheater safety valve branches, must be specially examined for cracks/fractures using Magnetic Testing (MT) when necessary.

 

• High-temperature pressure parts, such as superheater outlet headers and manifolds, are susceptible to creep damage, which can lead to failure. The highest metal temperature occurs at the internal surfaces of such pressure parts that are not heated by hot gases, where cracking can begin. Typically, these cracks are not discovered until the entire thickness has been penetrated.

 

• All water gauge and pressure gauge connections must be clear of obstructions, and their shut-off fittings must be clearly and correctly marked to indicate when they are in the open position. High and low water level alarm fittings, as well as feed water regulators, must be inspected.

 

• All content gauge and pressure gauge connections must be clear of obstructions, and their shut-off fittings must be clearly and correctly marked to indicate when they are in the open position. Alarm fittings for high and low content levels, as well as feed content regulators, should be examined.

 

Boiler inspection under operating conditions will include:

 

• Calibration of the boiler pressure gauges is verified. Where the calibration cannot be easily verified, a written statement from the Master/Chief Engineer confirming that the gauges have been calibrated must be obtained. Alternatively, a second gauge for verification of the primary gauge may be considered.

 

• Using a methodical blowdown sequence to ensure that water level indicators are working properly.

 

• Bench tested valves previously set under workshop conditions are compared to respective pressures set at sea.

 

General requirements (Steam Stop Valves)

 

• The mountings (including all valves, burner units, fittings, drains, and filling valves) must be opened for internal inspection and, if necessary, rectification. The attending Surveyor(s) must ensure that all mountings are securely fastened and that any insulation that prevents full examination of studs and nuts is removed. Stub piece welds will be examined for shell attachment.

 

• Shell plating in the form of nozzles penetrating the shell (feed, gauge glasses, etc.) and pads attached to the shell must be thoroughly inspected for cracks that may be caused by welds.

 

• Welded connections of stub pipes to integral steam piping, particularly superheater safety valve branches, must be specifically examined for cracks/fractures using Magnetic Testing (MT) when necessary.

 

• High-temperature pressure parts, such as superheater outlet headers and manifolds, are susceptible to creep damage, which can lead to failure. The highest metal temperature occurs at the internal surfaces of such pressure parts that are not heated by hot gases, where cracking can begin. Typically, these cracks are not discovered until the entire thickness has been penetrated.

 

• It is important that all water gauges and pressure gauge connections are to be free from obstructions and their shut-off fittings clearly and correctly marked to indicate when they are in the open position. High and low water level alarm fittings and also feed water regulators are to be examined.

 

• It is important that all content gauges and pressure gauge connections should be free from obstructions and their shut-off fittings clearly and correctly marked to indicate when they are in the open position. High and low content level alarm fittings and also feed content regulators should be examined.