Spectacle Pieces

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Following on from notification to the Club of several claims incidents concerning spectacle pieces, we would like to remind Members of the importance of utilising these pipeline blanks effectively.

Valve
Butterfly valve

Spectacle pieces are utilised in cargo pipelines to ensure positive segregation between cargo systems/sections of pipeline. It is an accepted industry norm that when gate valves are fitted to a system, two such valves between different grades will afford the required isolation. However, many ships today are fitted with butterfly valves, due to their design they cannot be relied upon to provide the same degree of tightness when closed as that afforded by gate valves. It is therefore necessary to ensure that spectacle pieces are used to ensure total segregation and not to rely totally upon butterfly valves alone.

Every effort should be made to ensure the ‘swinging’ of a spectacle piece is made as easy as possible so that it does not become an arduous task for the crew. This might include ensuring the nuts and bolts are free of rust/paint and well greased to the provision of a pneumatic spanner.

Spectacle pieces may also be utilised when a vessel has experienced leaking valves into the cargo system be they sea valves, cross connection to ballast system or indeed cargo valves. When this is the case it must be remembered that this is only a temporary measure and the spectacle piece should not be left in place for an extended amount of time.

When a spectacle piece is inserted for this reason, a positive overhaul plan should be put in place to rectify the problem at the earliest opportunity.

When a spectacle piece is inserted into a pipeline it should be made as conspicuous as possible and all staff associated with cargo operations should be made aware of its existence. Prior to every cargo related operation the spectacle piece should be checked to ensure that the correct section is located within the pipeline system.

The importance of this equipment being used correctly cannot be underestimated as it is a last defence for containing cargo if it leaks/passes through valves between systems.

 

pipeline 1
Blank located out of the pipeline

pipeline 2
Blank inserted in the pipeline