GOV: gross observed volume
TOV less FW and bottom sediment, being the measured
volume of oil and S&W at observed temperature and pressure. In practice, GOV is
usually calculated with no deduction for bottom sediment, which is very difficult to
GSV: gross standard volume
Measured volume of oil and S&W at standard conditions
of 15ºC and atmospheric pressure. In practice, the GSV is the GOV multiplied by the
VCF obtained from the appropriate ASTM
The GSV is
the primary quantity measured and reported on tankers.
High level sensor
An electrical or mechanical device designed to indicate when a cargo
tank is filled to maximum level.
The introduction of a chemically un-reactive gas into cargo or ballast spaces to
minimise the risk of explosion.
The initials for the Institute of Petroleum.
The more volatile component of a particular crude or product.
LOT: load on top
The procedure of comingling the recovered oil slops with the next
NSV: net standard volume
Only applicable to crude oil, NSV is the GSV minus S&W,
being a measurement of the ‘dry’ oil quantity at standard conditions. For products, S&W
is not normally deducted and is included (where appropriate) within the receiver’s
quality specifications. Whereas samples of crude and product are commonly drawn from
ship’s tanks after loading (and before discharge), the measured S&W is not advised in
time for ship’s officers to calculate the NSV on board.
A combination carrier having holds designed such that they can be used
to carry either dry or liquid bulk cargoes.
OBQ: on-board quantity
Any material (oil, water, sludge and sediment) in cargo spaces
and associated lines and pumps on a tanker after de-ballasting and before start of loading
operations. OBQ measurement is restricted to bottom soundings and is usually made
under stern trim.
A combination carrier which, unlike an OBO, possesses wing tanks.
and bulk cargoes are never carried at the same time.
The quantity of cargo discharged from a tanker, as received by a shore terminal.
Passivation of stainless steel involves the thickening of its surface layer of
chromium oxide to increase corrosion resistance.
Pickling of stainless steel involves the chemical removal of oxidation products
generated during welding.
Localised corrosion typified by the formation of a cavity.
The lowest temperature at which an oil can be poured under prescribed
conditions of tests.