ALL LEVEL SAMPLE - An all levels sample is obtained by submerging a stoppered container to a point as near as possible to the draw-off level of a tank, and above any free water, then removing the stopper and raising the container at a rate such that the container is about 70% full (no more than 85%) as it emerges from the liquid.
API - The American Petroleum Institute, founded in 1919, was the first oil trade association to include all branches of the petroleum industry
API GRAVITY is the density of the petroleum product and may be measured by a hydrometer instrument having a scale graduated in degrees API.
AUTOMATIC GAUGING SYSTEM - An automatic gauging system is a computerized system used to determine the total gross volume in a tank. Various manufacturers, the system can be fitted to shore tanks, barges and ships. (see VAREC gauge)
AUTOMATIC SAMPLER –A device used to extract a representative sample from the liquid flowing through a pipeline. The sampler comprises of several parts including a programmer to enable a representative sample to be obtained. Used extensively at crude oil terminals.
BACK PRESSURE the operating pressure level measured downstream from a measuring device i.e. pressure gauge.
BACON BOMB –a sampler --for sample - taking of liquid products at the bottom or intermediate points of a vessel or shore tank. The Bacon Bomb obtains samples from storage tanks, vessels, tank cars and drums. When the sampler strikes the bottom of the tank, a plunger assembly opens to admit the sample. The plunger closes again when the bomb is withdrawn, forming a tight seal. Samples can be taken at any depth with the use of a secondary trip line, or extension rod.
BARREL (BBL) - A unit of volume equal to 42 U.S. gallons or 9702.0 cubic inches
BARGE A barge is a flat-bottomed vessel built mainly for river and canal transport of dry and liquid i.e. petroleum goods. Most barges are not self-propelled and need to be towed by tugboats or pushed by towboats.
BALLAST is the water taken on a vessel, typically when it is empty or partly loaded to increase draft, improve steering, properly submerge the propeller and maintain stability and trim. See also Designated Ballast Tank, Dedicated Ballast and Permanent Ballast Tank.
BEAM the extreme breadth of a vessel.
BELLSUCTION the flared open end of a cargo pipeline pump suction, which is situated at close tolerances to the bottom of a liquid cargo tank. (See submersible pump)
BILGE the radius of the rounded space portion of a vessel’s hull, connecting bottom and sides.
BILL OF LADING (sometimes referred to as a BOL or B/L) is a document issued by a carrier to a shipper, confirming that specified goods have been received on board for shipment to a named place for delivery to the consignee. The B/L a) confirms receipt by the carrier b) confirms goods shipped c) describes the goods and names the shipper and receiver.
BOTTOMS are the product remaining below the pump suction point in a vessel cargo tank. Frequently encountered with heavy oil heated cargoes. Modern tanker ship design has minimized this occurrence. See OBQ and ROB.
BOW the forward or front end of a vessel.
BOTTOM SAMPLE - A bottom sample is a “spot” sample of the material obtained from the tank bottom. In practice the term Bottom sample has a variety of meanings.
BULKHEAD an upright partition –longitudinal or transverse-separating vessel cargo tank compartments.
BUNKERS is the combustible fuel used for operating the ship main engines and auxiliaries i.e. generators and boilers (for cargo heating the material being transported.)
BULBOUS BOW is a standard feature on large modern ships. It is a protruding bulb at the bow below the waterline. The bulb modifies water flow reducing drag and increasing fuel efficiency.
BUTTERWORTH is a cargo tank washing process used to gas free and/or or clean a cargo tank for the next cargo. The system employs hot water or chemicals, sprayed through a patented rotating nozzle fitted machine. BUTTERWORTH opening -- a deck access opening with bolted cover, designed for tank cleaning operations. Equipment is “fixed” or “portable”. BUTTERWORTH is the name of the equipment manufacturer.
CALIBRATION OF AN INSTRUMENT - The process or procedure of adjusting an instrument, such as a meter or an electronic thermometer, so that its indication or registration is in satisfactorily close agreement with a reference standard.
CALIBRATION TABLES or CHARTS are volume tables that provide the tank volumes in each tank according to the liquid (innage) or space (ullage) measured in the tank.
CHARTER PARTY a contractual agreement between two entities for the purpose of renting, hiring, or leasing the exclusive use of a vessel.
CIF Cost, Insurance, and Freight; cost of transportation and insurance to be paid by the seller of goods to the named point of destination.
CLEAN OIL is commonly known to the industry as a lighter (higher API Gravity), light in color and liquid texture. This includes gasolines and heating oils.
CLEARANCE SAMPLE - A clearance sample is a spot sample taken 4 inches below the tank outlet level.
CLOSED GAUGING AND SAMPLING portable equipment for vessel tanks--is designed to be completely gas-tight during operation to prevent release of vapor to the atmosphere. (See Restricted Gauging and Sampling)
COLONIAL PIPELINE COMPANY is an interstate common carrier of petroleum products. Via the company pipeline system it delivers gasoline’s, kerosene’s, home heating oils and diesel fuels.
Colonial Pipeline Company quality specifications are widely use by buyers and sellers.
CLINGAGE is the cargo that adheres to the internal surfaces of a vessel cargo tank after it has been emptied.
CLOSING GAUGE is an Innage or Ullage measurement taken upon completion and after the product is transferred into or out of a tank.
CLOSED GAUGING SYSTEM - A method of obtaining measurements of the tank contents without opening the tank. This may be accomplished by using automatic tank gauges or by taking measurements through a pressure/vapor lock standpipe. This type of gauging is performed on vessels with inert gas systems. When the electronic probe senses hydrocarbon, a steady tone is heard; when sensing water, it emits an intermittent tone. Temperature is shown on an LED display in the hub of the instrument
COFFERDAM is a small transverse tank space between two vessel bulkheads. Oil tankers generally have cofferdams forward and aft of the cargo tanks. This provides protection from heat and fire.
CARGO COMPARTMENT an interior space of a vessel’s hull, which is formed by bulkheads and used for the carriage of cargo.
COMPOSITE SAMPLE - A blend of spot samples mixed in proportion to the volumes of material from which the spot samples were obtained. Refer below for API recommendations. Note Operations/Dispatch frequently has additional sampling requirements.
For tanks with greater than 1,000 Bbls capacity, spot samples are collected in the following ways:
i. For tanks containing more than 15 feet of product, at three levels.
ii. For tanks containing between 10 and 15 feet of product, at two levels.
iii. For tanks containing less than 10 feet of product, one middle spot sample at the center of the product.
CORRECTED GAUGE is the Vessel Physical/ Observed Gauge corrected for the vessels trim and/or list as applicable.
CRITICAL ZONE Shore Tank Floating Roof, the Critical Zone is the point in the tank where the roof is changing from floating to non floating i.e. resting on support legs. It is the distance between the points where a floating roof in a shore tank is resting on its normal supports to the point where the roof is floating freely. Measurement accuracy in not possible in the Critical Zone.
CRUDE OIL WASHING (COW) is a method for washing tanks on a crude oil vessel. The COW system circulates part of the crude oil cargo through the fixed tank cleaning system (see Butterworth) to remove residues and sediments in the cargo tanks. The crude oil is very effective in the cleaning operation. The COW is performed simultaneously during the cargo discharge and IGS is maintained at all times.
CUT - The oil level on the tape or bob or the water level marking on a tape or bob coated with water indicating paste. “Taking a cut” is taking a measurement of the oil or water level.
CUBIC METRE The cubic metre (US spelling: cubic meter, symbol: m3) is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. One Metre = 39.37 inches
DATUM PLATE is a level metal plate located on the shore tank bottom directly under the reference gauge point to provide a fixed contact surface from which liquid level measurement can be made.
DEDICATED BALLAST TANK is a ship tank maintained clean and available for “clean” ballast. It is within the cargo tank and pipeline system and is not separate as is a Permanent Ballast Tank. (which see) All tanker ships calling at US ports are required to be constructed with PBT.
DEMURRAGE a charge assessed for detaining a vessel beyond the free time stipulated for loading or unloading. (DISPATCH is the reciprocal of Demurrage)
DEADWEIGHT TONNAGE the cargo capacity of a vessel expressed in tons weight.
DEADWOOD - Internal tank fitting, or structural member, which affects the capacity of the tank.
DESIGNATED BALLAST TANK see Dedicated Ballast Tank
DIRTY OIL / BLACK OIL / RESIDUAL are commonly known by the industry as heavy oil (low API Gravity), dark in color and viscous in texture, a product that typically requires heating to maintain liquid state.
DOUBLE BOTTOM construction-- the void space between the cargo tank bottom plating and the bottom hull plating.
DOUBLE HULL is a ship hull design and construction method where the bottom and sides of the ship have two complete layers of watertight hull surface: one outer layer forming the normal hull of the ship, and a second inner hull which is constructed further into the ship. This forms a “double skin” redundant barrier to seawater in case the outer hull is damaged and leaks.
DRÄGER is a manufacturer of portable gas detection and analysis equipment systems. This field equipment is used for field detection of gases in PPM i.e. Hydrogen Sulphide. This field test is also referred to as “sniffing”. (See Hydrogen Sulphide)
DRAFT of a vessel hull is the vertical distance between the waterline and the bottom of the hull (keel) or it is a vessel's depth below the water line, measured from the surface of the water to the bottom of the vessel's keel. Draft determines the minimum depth of water a ship or vessel requires to safely navigate.
DRAFT MARKS (or Draft Scale) the vessel draft is measured at bow and stern and middle of vessel. Draft marks are ‘cut” or welded at these points. The marks may use traditional English (12 inch intervals) or metric units (20 cm intervals). Older vessels were marked with Roman Numerals (at 12-inch intervals).
DRAIN SAMPLE - a drain sample is obtained from the water draw-off valve on a storage tank.
DENSITY is a measure of how much mass is contained in a given unit volume (density = mass/volume). Put simply, if mass is a measure of how much ‘stuff’ there is in an object; density is a measure of how tightly that ‘stuff’ is packed together. One way to see how density affects things is to look at how objects float or sink in water. If an object is denser than water, it will sink, and if it is less dense it will float. This is why an anchor (very dense) sinks, but an inner tube (not very dense) floats.
ETA Estimated Time of Arrival
ETD Estimated Time of Departure
EMULSION an oil/water mixture that does not readily separate.
FLOW PROPORTIONAL SAMPLE – (In Line Automatic Sampler) a flow proportional sample is taken from a pipeline during the entire transfer. The rate of sampling is proportional to the flow of the liquid in the pipe at any instant.
FREE WATER (abbreviated FW) is the volume of water that is not in suspension in the petroleum liquid. A separate phase typically found at the lower layer.
FREEBOARD the distance from the water surface (waterline) to the main deck of a ship or barge.
FLOATING ROOF An External or Internal floating roof tank is a storage tank used to store large quantities of volatile petroleum products such as crude oil or gasoline or chemical products. It comprises an open- topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid. The roof rises and falls with the liquid level in the tank. As opposed to a fixed roof tank there is no vapor space (ullage) in the floating roof tank (except for very low liquid level situations). In principle, this eliminates loss of vapor by greatly reducing evaporative loss. There is a rim seal system between the tank shell and roof to reduce rim evaporation. The roof has support legs suspended into the liquid. At low liquid levels the roof eventually lands and a vapor space forms between the liquid surface and the roof, similar to a fixed roof tank. The support legs are usually equipped for two settings to increase the working volume of the tank and aid maintenance. As the “roof” floats in the liquid a “Roof Correction” (see below) is made in quantity calculations. External Floating Roofs can accumulate rain, ice and snow on the roof which must be considered in quantity calculations. (See Roof Correction)
F.O.B. Free On Board; cargo delivered to and placed on board a carrier at a specific point without charge.
GAS FREE the process of removing all hazardous gases and residues from the cargo compartments of a vessel during tank cleaning.
GAUGING A process of measuring height of a liquid in a storage tank usually using a weighted graduated steel tape and bob. See also CLOSED GAUGING SYSTEM.
GROSS TONS the volume measurement of the vessel internal compartments i.e. cargo spaces, engine room, crew accommodation of a vessel wherein 100 cu. ft. equals one ton.
GROSS OBSERVED VOLUME (GOV)
GOV = TOV – FW (Total Observed Volume – Free Water)
GOV is the total volume of all petroleum liquids and sediment and water, excluding free water at observed temperature.
GROSS STANDARD VOLUME (GSV)
GSV = GOV x VCF (Gross observed Volume x Volume Correction Factor)
GSV is the total volume of all petroleum liquids and sediment and water, excluding free water, corrected by the appropriate volume correction factor.
HYDROGEN SULFIDE (or hydrogen sulphide) is the chemical compound with the formula H2S. This colorless, highly toxic, flammable and poisonous gas is partially responsible for the foul odor of rotten eggs. Although very pungent at first, it quickly deadens the sense of smell, so potential victims may be unaware of its presence until it is too late. This gas is found in petroleum especially crude oils.
INNAGE (DIP) GAUGE - An innage (dip) gauge is the level of liquid in a tank measured from the datum plate or tank bottom to the surface of the liquid.
INERT GAS SYSTEM (IGS) An oil tanker's inert gas system is one of the most important parts of its design. Petroleum itself is very difficult to ignite; however its vapors are explosive when mixed with air in certain concentrations. The purpose of the system is to create an atmosphere inside cargo tanks in which the hydrocarbon oil vapors cannot burn. The IGS permits COW tank cleaning to be practiced in safety.
INERTING (with IGS) is a procedure used to reduce the oxygen content of a vessel's cargo spaces to 8 % or less. This procedure is performed by introducing an Inert Gas such as Nitrogen or Carbon Monoxide, a mixture of main engine exhaust gases such as flue gas.
INTERNAL CIRCULATION METHOD – this is a method of Shore Line Verification, by transferring a measured volume of liquid from one shore tank into the same tank or another shore tank containing similar product through the pipeline system designed for the inspection operation. This method is used to eliminate air or vapors from the line.
KEEL the lowest structural member of a ship or barge which runs the length of the vessel at the centerline and to which the hull frames are attached
LETTER OF PROTEST (LOP) is a written record of a particular action or finding that is questioned at the time of occurrence. The LOP is required to be issued within 24 Hours of the occurrence.
LINE DISPLACEMENT METHOD – this is a method of Shore Line Verification. This method is applied by measuring the volume of liquid pumped from a shore tank to a vessel (Load Transfer) or to a shore tank from a vessel (Discharge Transfer) through the pipeline system designated for the cargo transfer and comparing the measured volume delivered to the measured volume received. This is an alternate method used for Shore Line Verification.
LINE PRESS METHOD - this is a method of Shore Line Verification. This method is applied by pressurizing the contents of the designated shore pipeline system with product to fill the line and eliminate air or vapors. This is an alternate method used for Shore Line Verification.
LIST is the leaning or inclination of a vessel, expressed in degrees port (left side) or starboard (right side). It is the Transverse Inclination of a vessel.
LIGHTER a non self-propelled vessel, usually a barge that is used in loading or unloading a ship or in transporting cargo in and around a harbor or coastal waterway.
LIGHTERING the process of transferring cargo at sea or in port, from one vessel to another.
(also known as offshore transfer, ship-to-ship lightering, transshipment)
LOADLINE MARKS A set of permanent markings amidships and on both sides of the hull of an oceangoing vessel. The marks denote the vessels maximum legal operating draft under certain specified conditions i.e. season and geographical area. The marks are determined by one of the internationally recognized assigning agencies i.e. American Bureau (USA), Lloyds Register (UK), Nippon Kaiji Register (Japan).
LOAD ON TOP (LOT) is the act of loading product on top of existing cargo and commingling both products together.
Originally oil tankers used one set of tanks for cargo and about one third of the same tanks were for water ballast on non cargo voyages. High pressure, hot, seawater jets were used to clean the tanks and the mixture of seawater and residue called ''slops'' discharged into the sea, as was the oil-contaminated ballast water. Marine pollution controls prohibited this action and LOT was introduced.
The dirty residues from seawater washing water were placed in the Slop Tanks and Load on Top approach was to be adopted. The mixture of tank cleaning water and residue was put into a Slop Tank and allowed to separate into oil and water during the ocean voyage. The water portion was then discharged, leaving only crude oil in the slop tank. The new cargo was consequently loaded on top of the slops.
LOWER SAMPLE - A lower sample is a spot sample obtained at the midpoint level of the lower third of the tank contents.
METER PROVING - The procedure required to determine the relationship between the true volume of liquid measured by a meter and the indicated meter volume
MIDDLE SAMPLE - A middle sample is a spot sample obtained from the middle of the tank contents.
MULTIPOINT GAUGING is measuring a vessel tank through two or more openings in the top of the tank. Practiced for OBQ/ROB measurement.
NET STANDARD VOLUME (NSV)
NSV = GSV - S&W Gross Standard Volume – Sediment Water Volume %
NSV is the total corrected volume of all petroleum liquids, excluding sediment and water and free water.
NOTICE OF APPARENT DISCREPANCY is a written record of a significant volume difference found at the time of volume calculations and/or voyage analysis.
ON-BOARD QUANTITY (OBQ) is the material present in the vessel's cargo tanks, void spaces and pipelines before the vessel is loaded. (see ROB)
OBO ORE-BULK-OIL a combination carrier: a vessel designed and built to carry dry, bulk, or liquid cargo.
OPENING GAUGE is an innage or ullage measurement taken before the product is transferred into or out of a tank.
OUTLET SAMPLE - An outlet sample is a spot sample taken from the bottom of the tank outlet level, but not higher than 1 meter (39") above the bottom of the tank.
PARTIAL DISCHARGE is the act of discharging part of the cargo on board a vessel.
REFERENCE GAUGE HEIGHT is the distance from the datum plate or tank bottom to the reference gauge point. This distance should be clearly marked on the tank top near the gauge hatch and recorded in the tank's calibration table.
REFERENCE GAUGE POINT is a mark on the gauge hatch of a tank, which indicates the exact location where the gauging should be carried out.
REMAINING ON BOARD (ROB) is the material present in the vessel's cargo tanks, void spaces and pipelines after the vessel is discharged. (see OBQ)
RESIDUAL / DIRTY OIL / BLACK OIL are commonly known by the industry as heavy oil (low API Gravity), dark in color and viscous in texture product that typically requires heating to liquefy.
RESTRICTED Gauging and Sampling portable equipment for vessel tanks designed for use under restricted conditions with a limited loss of vapor. (see Closed Gauging System)
ROOF CORRECTION the shore tank floating roof correction is a function of the weight of the roof and the observed density [API Gravity] of the liquid it floats in. The roof correction is applied in quantity calculations. Information required for this calculation is: the Observed API Gravity of Contents, API Gravity for which tank chart was calculated and the correction in barrels/gallons for each degree of difference in API Gravity. (see Floating Roof)
RUNNING SAMPLE - a running sample is obtained by lowering an un-stoppered container from the top of the product level to the bottom of the outlet connection and returning it to the top of the product at a uniform rate of speed such that the container is approximately 75% full (no more 85%) when withdrawn from the product.
SBT Segregated Ballast Tanks (tanks dedicated to carriage of seawater ballast, never cargo). Also referred to as PBT Permanent Ballast Tanks.
SEA SUCTION VALVE is a valve used to control in take of sea water ballast on a vessel.
SEDIMENT AND WATER (S&W) is the non hydrocarbon solid material and water found in suspension in a petroleum product.
SHIP'S AGENT is responsible for ship/shore co-ordination. Clearing the vessel inbound and outbound. Ensuring vessels port operations are effectively co-ordinated and performed smoothly and safely, cargo is loaded and unloaded efficiently, and crewmembers needs are accommodated when in port. Ships are normally in port for short periods, so the advance preparation needs to be effective.
SIDE GAUGE (“Varec”) Shore tank measuring device. Changes in the liquid level inside the tank raise or lower a large stainless steel float. The float is attached to a perforated tape and sprocket wheel. This provides shore tank “side gauge” readout and can be adapted to provide a remote readout within the storage facility.
SINGLE TANK COMPOSITE SAMPLE - A single tank composite sample is an equal blend of the upper, middle and lower spot samples. For tanks of uniform cross section, such as an upright cylindrical tank, the blend consists of equal parts of the three samples.
STRAPPING TABLE A chart used to convert readings of liquid levels in the tanks of a shore tank or barge to volume measurements of that liquid.
SLOPS are oil, oil/water/sediment, and emulsions contained in slop tanks or designated cargo tanks. The mixture is usually a result of tank stripping and washing. (see LOT)
SLUDGE is a highly viscous mixture of oil, water, sediment and residue.
SPOT SAMPLE - A spot sample is a sample taken from a specific level of a tank or from a pipe at a specific time during a pumping operation.
STOP GAUGE is a pre-determined innage or ullage gauge representing a specific volume of cargo within a tank.
STATIC ELECTRICITY refers to the buildup of electric charge on the surface of objects.When liquids flow through pipelines, friction is generated resulting in static electricity. Discharge of
static electricity can create severe hazards where a small electrical spark may ignite explosive mixtures.Lightning is a natural static discharge.
SUBMERSIBLE CARGO PUMP a cargo handling system either electric deep well pump or hydraulic submersible pump systems. Both systems comprise of cargo pumps located inside the cargo tank i.e. one cargo pump per tank.
SURFACE SAMPLE - A surface sample is a sample skimmed from the surface of a liquid in a tank.
TANK-SIDE SAMPLE - A tank side sample is a spot sample taken from a sample connection located on the side of the tank.
TANK an enclosed space used for holding liquids.
TANKER is a cargo ship used for the transport of liquids such as crude oil, petroleum products, liquefied petroleum gases, liquid chemicals, and vegetable oils. The tanker is equipped with pipelines and pumps to load and discharge the cargo.
THERMOPROBE –product name for a portable digital thermometer. The instruments are intrinsically safe and accurate to API requirements. Measurement is in temperature F and/or C degrees.
TOP SAMPLE - A top sample is a spot sample obtained 6 inches below the top surface of the liquid.
TOTAL CALCULATED VOLUME (TCV) TCV = GSV + FW
TCV is the total corrected volume of all petroleum liquids and sediment and water, corrected to a standard temperature plus all free water measured at observed temperature.
TOTAL OBSERVED VOLUME (TOV) is the total of all petroleum liquids, sediment and water, and free water at the observed temperature.
TRIM is the difference between the forward and aft drafts of a vessel, expressed by the head or by the stern. It is the longitudinal inclination of the vessel.
TUBE or THIEF SAMPLE - A tube or thief sample is obtained with a sampling tube or special thief sampler from a specified point in the tank or container.
TUGBOAT A tugboat is a boat used to maneuver, primarily by towing or pushing other vessels in harbors over the open sea or through rivers and canals. They are also used to tow barges, disabled ships, or other equipment such a towboats.
ULLAGE OPENING a small, covered opening in the top of a cargo tank through which measurements are made to determine the level of the liquid in the tank
ULLAGE (OUTAGE) GAUGE - An ullage (outage) gauge is the distance from the surface of the liquid in a tank to the reference gauge point of the tank.
UTI (Ullage -Temperature-Interface) Portable closed system gauge tapes. Gas tight liquid level gauges designed to measure petroleum and chemical tanks—simultaneously measuring temperature and water interface. The unit is equipped with digital readout. Requires dedicated vapor control valve fixed on the tank. Used for custody transfer on vessels and shore tanks.
UPPER SAMPLE - An upper sample is a spot sample taken at the midpoint level of the upper third of the tank contents.
VAREC (SHORE TANK SIDE GAUGE) is the brand name of a tank gauging equipment manufacturer. A number of companies manufacture similar equipment, but industry practice is to refer to all shore tank side gauges as “Varec” gauges.
VESSEL EXPERIENCE FACTOR (VEF) - The VEF is a calculated value based on statistical comparisons between TCV quantities delivered or received by the Vessel, against the corresponding Shore measurements, at either load or discharge ports.
VESSEL LOAD RATIO (VLR) =Vessel Quantity Received / Bill of Lading.
VESSEL DISCHARGE RATIO (VDR) = Vessel Quantity Delivered / Outturn.
VLCC Very Large Crude Carrier (can refer to vessels over 160,000 DWT or 200,000 DWT).
VOID SPACE any enclosed space within the vessel construction not used as a machinery space or seawater ballast, freshwater or a space for the carriage of cargo.
VOLUME CORRECTION FACTOR (VCF) - The VCF is a factor used for converting volumes at an observed temperature and gravity or density to a standard temperature (60 F or 15 C).
WALL WASH TEST is the pre load procedure of washing selected areas of a vessel's tank interior. Collecting and testing the wash liquid for the presence of material which may contaminate the cargo to be loaded. Widely used for preload inspection of chemical products.
WATER CUT MEASUREMENT is the procedure of locating the product / water interface for determining the volume of free water in a shore tank or vessel compartment.
WATER WASHING is a method for washing vessel's tanks. It involves the use of a high-pressure water stream to dissolve clingage and sediment from the bulkheads, bottom, and internal tank structures of a vessel.
WEDGE FORMULA is a mathematical formula use for calculating small amounts of liquid materials (OBQ’s and/or ROB’s) on board a vessel. The wedge formula is used when the liquid material is not in contact with all bulkheads of the vessel's tank.
WIPE TEST is the procedure of randomly wiping the interior of a vessel tank with an absorbent white rag. This procedure is used to test the tank's coating for possible color contamination on cargo to be loaded.
ZONE SAMPLER for use in tanks and vessels. The zone sampler is designed to take samples at any level. It has a stainless valve and alignment system to assure better sealing without leakage.