OIL MIST DETECTOR MARK 5

Oil Mist Detector – Graviner Mark 5

This is an oil mist detector, specifically the Mark 5 model manufactured by Graviner. It is a critical marine safety device used on ship engines to detect the presence of oil mist inside engine crankcases, helping prevent dangerous and potentially catastrophic failures.

What it is

An oil mist detector (OMD) is an essential safety monitoring system installed on large marine diesel engines. Its primary function is to continuously monitor the internal atmosphere of the crankcase and detect abnormal levels of oil vapor or mist. These systems are mandatory on many commercial vessels and are required to comply with international maritime safety regulations.

Why it’s important

Oil mist formation inside an engine crankcase can indicate serious mechanical issues and poses significant risks, including:
• Crankcase explosions
• Severe engine damage
• Increased fire hazard

Early detection is crucial, as oil mist can ignite if it reaches a critical concentration and encounters a hot surface or spark. The Graviner Mark 5 helps prevent such incidents by providing early warning to the crew.

What it does

• Continuously samples and monitors air from different areas within the engine crankcase
  • Detects microscopic oil particles suspended in the air
  • Triggers an alarm if oil mist concentration exceeds safe limits

This real-time monitoring ensures that even small deviations are detected before they escalate into serious problems.

How it works (simple explanation)

• Air samples are drawn from multiple points inside the engine
  • The device uses optical detection (light scattering or opacity measurement)
  • When oil mist concentration increases, the light signal changes
  • The system processes this change and activates an alarm if thresholds are exceeded

What happens on alarm

• Visual and audible alarms are activated on the control panel
  • The crew is immediately alerted to a potential hazard
  • Operators must take action, such as:
  o Reducing engine load or stopping the engine
  o Inspecting for overheating, bearing failure, or lubrication issues

What you see

• A central control unit with display and status indicators
  • Sampling connections located underneath the unit
  • Alarm lights and system status indicators

Important note

The listing mentions: “ALARM SIGNAL IS NOT WORKING”, which indicates that the alarm functionality may be faulty and the unit likely requires inspection, maintenance, or repair before safe operation.

Simple explanation

In simple terms, this device is an early warning system for ship engines. It detects dangerous oil vapor inside the crankcase before it can ignite, helping prevent fires, explosions, and costly engine damage while ensuring safe vessel operation.