QUESTION 10.7.2

Preventing oil spray onto hot machinery surfaces

Oil, Chemical, LPG, LNGEngine Room

What is being checked

The inspector is checking whether hot surfaces are insulated below ignition-risk temperatures and flammable-oil systems are shielded, jacketed and maintained so a leak cannot produce an engine-room fire.

Ready onboard

0/7 complete

HOT-SURFACE SURVEYExhausts, indicator cocks, turbochargers, boilers and other surfaces above 220 C are identified and effectively insulated.INSULATIONLagging and metal cladding are complete, dry, secured and free from oil contamination.SPRAY SHIELDINGFlanged joints, filters, valves and other pressurised oil leak points are screened or arranged away from ignition surfaces.JACKETED PIPESHigh-pressure fuel lines, leak-off collection and alarms are intact and unobstructed.LEAK RESPONSEActive seepage is repaired promptly and contaminated insulation is renewed, not merely wiped or painted.THERMOGRAPHYPeriodic temperature surveys cover the plant under representative load and findings are closed.HOUSEKEEPINGBilges, drip trays and purifier or boiler areas remain free of accumulated oil and waste.

Practice questions

Answer aloud, then open the preparation point.

1What surface-temperature limit is used for fire prevention?

SOLAS controls exposed surfaces above 220 C that may be impinged by a flammable-system failure; apply the vessel survey and insulation standard.

2Why must oil-soaked lagging be replaced?

Oil retained inside insulation can reach a hot surface and ignite even when the outer cladding looks clean.

3How are hot spots found?

Conduct a representative-load thermal survey and combine it with close inspection of missing cladding, joints and shield condition.

4What is the purpose of jacketed fuel pipes?

The outer pipe captures high-pressure leakage and leads it to a drain or alarm rather than allowing atomised spray.

5Which recent maintenance can create new risk?

Disturbed exhaust insulation, misaligned shields, loose fuel fittings and blocked leak-off pipes require post-work inspection and load verification.

Where an observation may arise

EXPOSED HOT SPOT

A surface above the applicable threshold lacks effective insulation.

OIL-SOAKED LAGGING

Contaminated insulation remains in service or is concealed by new cladding.

SPRAY PATH

A pressurised fuel or lubricating-oil joint can discharge onto a hot surface.

JACKET DEFECT

Double-wall piping, leak collection or alarm is incomplete or blocked.

ACTIVE LEAK

Oil seepage is accepted or caught by an improvised container.

SURVEY GAP

Temperature checks are absent, outdated or conducted only at low load.

Master's practical note

Inspect after recent work and at representative load. Fires often begin where insulation or spray shielding was disturbed during otherwise successful maintenance.

Equipment boundary and references

Equipment boundary: The 220 C criterion comes from SOLAS fire-prevention requirements, but lower-temperature risks and maker limits still require control. Thermal imaging does not replace physical inspection beneath suspect cladding.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 10.7.2
SOLAS Chapter II-2 regulation 4.2.2.6
IMO MSC.1/Circ.1321
IACS UR M15
Manufacturer instructions

Last reviewed: 2026-09-10