valve operated by use of a wrench.
Ensure the pumproom exhaust fans are fully operating and never enter a pumproom on your own. Refer to specific SGS documentation which covers procedures and risks on this topic.
8.1.8 Cargo Separation
• In the event the officer-in-charge does not permit the removal of previously installed seals, a LOP should be issued. The inspector, however, should proceed with the sealing of the valves upon confirming that they are set in a closed position. • Where sealing is not possible, as in hydraulic valves, verify that there are protocols to prevent crew members from accidentally operating such valves. 8.1.12 Isolation of Inert Gas Lines on Marine Vessels When loading multiple grades of product onto marine vessels, avoidance of contamination of grades is always of paramount concern; especially, when high and low flash-point grades are loaded onto the same vessel. In these situations, we tend to concern ourselves with ensuring that the different liquids do not come into contact with one another via such things as common loading lines or leaking valves. Nonetheless, there have been a number of recorded cases whereby high flash-point cargoes have been contaminated, not from the liquid but from the vapours of low flash-point cargoes that have found their way into the high flash-point cargo tanks by way of common inert gas lines.
It is important to maintain separation of the cargo from the ballast system and from sea water. This is usually performed by sealing valves in the pump room. With ballast systems it is important to seal any valves that link the ballast system to the cargo system. When considering separation of the cargo from sea water, there are two sets of valves that we are interested in; the sea suction valve and any overboard discharge valves. 8.1.9 Sea Suction and Overboard Discharge Valves There is usually just one Sea Suction valve but can be two in some situations. They are usually located at the bottom of the pumproom. It is very important to seal these valves. There is normally two overboard discharge valves, port and starboard; however, there may only be one. They are usually in the pumproom but can even be located on deck. It is important to seal these valves as this would be a way in which cargo could be pumped overboard.
8.1.11 Procedures
• View and study the piping arrangement diagram, prior to going into the pumproom, to confirm the location of the sea suction valves, overboard discharge valves, connecting pipelines and their related valves. • Whenever there is a requirement to seal valves connected to cargo and ballast systems, all existing seals from previous voyages are to be removed, following permission from the officer-in- charge, and record the removed seals for reference purposes. • As far as possible, physically check valves to verify that they are set and secured in the closed position; however, do not operate any valves yourself. • A Letter of Protest should be issued if physical verification is not permitted. Sealing should proceed only upon confirming that the valves are secured in a closed position. • Connecting lines and valves should also be subjected to inspection. Sealing should be conducted in such a manner to ensure that the valve cannot be turned without breaking the seal. This is usually best achieved by sealing the valve handle to the body of the valve. Many valve handles are capable of being removed and the
8.1.10 Safety
Sealing of these valves is usually done in the vessel’s pumproom, which is a confined space.
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