Improperly closed drain valves on unused connections can come back and bite you, warns the Marine Safety Forum, so check they’re closed.
Says an MSF Safety Flash: After completion of the wet bulk loading checklist the vessel commenced backloading OBM through the midship connection. Upon checking the unused connections after loading commenced, a leak was noticed from the drain valve of the port aft mud manifold.
The operation was stopped and the valve checked for closure before the operation recommenced. After restarting the backload, the valve was rechecked, no further leakage was found and the operation was completed without further incident.
This incident had the potential to cause a significant pollution incident and highlights the need for pre-loading checklists to be carried out thoroughly. The following points should be considered when completing pre-loading checks.
- All unused manifolds should be checked to ensure caps are on and valves are closed fully.
- Drain valves should be checked to ensure they are fully closed.
- Scuppers should be plugged.
- Save-All drains should be plugged around all connections and not only the connection in use.
In this instance the drain valve of the unused connection was found to be passing slightly as it was not fully closed.
Pre-loading checklists should be completed in full and not just as a tick box exercise. Vessels should ensure that all crew members involved in carrying out the pre-loading checks are aware of the consequences of not fully carrying out the necessary checks. All crew members involved in the
operation should participate in the Risk Assessment process and attend a Toolbox Talk prior to commencing the job.