Not Logged In, Login,

Thursday, July 19, 2018

PUMPING WARRANTIES - THE IMPACT OF SHORE BOOSTER PUMPS

Within all traditional pumping clauses there is the alternative requirement that a vessel must maintain 100 psi at her manifold throughout a discharge. As will be seen in the INTERTANKO publication on pumping, currently being finalised, this pressure is generated by both the resistance to flow of the oil cargo being discharged and the static head created by any gradient in the pipeline or liquid level in shore tanks.

The resistance to flow of oil in a pipeline is dependent upon many parameters, amongst which is the length of the pipeline.

A shore booster pump will normally be used when discharging in ports which have very long discharge pipelines or where there is a substantial rise in the gradient of the pipeline.  For example, at the port of Genoa booster pumps are invariably used as the shore tanks are located well above the shore facility.

The action of the shore booster pump when placed in series will not increase the volumetric rate of flow but will supply additional energy to overcome all the resistances to flow within the shore pipeline system.  When a shore booster pump is placed in series with the vessel’s main cargo pumps it will have an impact upon the pressure registered at the vessel’s manifold.  The act of using a booster pump will artificially reduce the length of the shore pipeline system, i.e. there will be a reduction in the resistance to flow and pressure at the vessel’s manifold could be seen to fall. This will be so even if the vessel’s pump(s) are working at maximum efficiency. The volumetric rate of flow will be dependent upon the capacities of the pumps in series and the rate at which they can displace liquid from the pump.

The use a booster pump by the shore facility during a discharge may make it difficult for a vessel to fulfil one of the pumping clause’s requirements of maintaining 100 psi at the manifold.  Provided that the vessel can ascertain that use is being made of a booster pump facility due note should be made on the pumping pressure report and a letter of protest issued.

Should any member wish to discuss any pumping disputes they should contact john.fawcett-ellis@intertanko.com