Extended Operational and Trade Vocabulary

Marine Lubricants and Cylinder Oils glossary

The marine-lubricant vocabulary: acid neutralization by alkaline reserve (BN) against fuel-sulfur acids, scrape-down iron analysis for liner wear, additive packages, aeration and antifoam, and the cylinder-oil feed-rate terms. Grounds each term in the lubricant chemistry or the engine-tribology function it serves.

313 defined terms.

Showing 250 on this page (page 1 of 2).

A

Abrasion: Mechanical wear of liner and ring surfaces caused by hard particles such as cat fines, quantified through iron content in scrape-down analysis.
Acid neutralization: Function of alkaline additives in cylinder oil that react with sulfuric acid formed from fuel sulfur combustion to prevent corrosive liner wear.
Additive package: Engineered chemical blend (detergents, dispersants, anti-wear, anti-foam) added to base oil to produce a finished lubricant.
Aeration: Forced air movement through cargo to control temperature, gas, or moisture.
Alfa Laval separator: Centrifugal purifier widely used to clean system oil of water and insoluble contaminants in marine diesel installations.
Alkaline reserve: Quantity of base additive remaining in a used cylinder oil that can still neutralize combustion acids, measured by Base Number.
Alkalinity: Capacity of seawater to neutralize acid, a key parameter of the carbonate system.
Alpha Lubricator: MAN ES electronically controlled cylinder lubrication system relevant to the prime mover driving the shaft line.
Ambient viscosity: Kinematic viscosity of a lubricant at storage temperature, relevant to pumpability in cold bunker tanks.
Antifoam additive: Silicone or polyacrylate species added to system and hydraulic oils to break foam at the oil and air interface.
Antioxidant: Additive such as hindered phenol or aromatic amine that retards oxidative degradation of base oil in service.
Antiwear additive: Compound such as ZDDP that forms a tribochemical film on rubbing surfaces to reduce wear in hydraulic and gear oils.
API base oil group: American Petroleum Institute classification of base stocks into Groups I through V based on sulfur, saturates, and viscosity index.
Argina: Shell range of medium-speed trunk piston engine oils for four-stroke engines burning residual or distillate fuels.
Aromatic content: Concentration of aromatic hydrocarbons; influences CCAI and ignition behavior.
Ash content: Inorganic residue after combustion of a fuel sample, measured per ISO 6245, capped at 0.100% m/m for most residual grades.
ASTM D2270: Standard practice for calculating viscosity index from kinematic viscosities at 40 and 100 degrees Celsius.
ASTM D2622: Sulfur in petroleum products by wavelength dispersive X-ray fluorescence.
ASTM D2896: Standard test method for Base Number of petroleum products by potentiometric perchloric acid titration, the reference method for fresh cylinder oils.
ASTM D445: Standard test method for kinematic viscosity of transparent and opaque liquids.
ASTM D4739: Base number determination by potentiometric titration.
ASTM D4951: Standard test method for additive elements in lubricating oils by inductively coupled plasma atomic emission spectrometry.
ASTM D5185: Standard test method for multielement determination of used and unused lubricating oils by ICP-OES, the primary wear metals method.
ASTM D5800: Standard test method for evaporation loss of lubricating oils by the Noack method.
ASTM D6595: Standard test method for determination of wear metals and contaminants in used lubricating oils by rotating disc electrode atomic emission spectrometry.
ASTM D92: Standard test method for flash and fire points by Cleveland open cup tester.
ASTM D97: Standard test method for pour point of petroleum products.
Aurelia TI 4030: Total Lubmarine trunk piston engine oil with 30 BN for medium-speed engines burning distillate or low-sulfur residual fuel.
Aurelia XT 4040: Total Lubmarine 40 BN trunk piston engine oil formulated for residual fuel operation in four-stroke marine engines.
Automatic lubricator: Mechanical or electronic device that delivers metered quantities of oil to specified injection points on an engine cylinder.
Auxiliary engine oil: Trunk piston engine oil used in medium-speed gensets, typically 30 to 40 BN depending on fuel sulfur.

B

Bactericide: Biocidal additive sometimes used in water-glycol hydraulic fluids and water-mix coolants to control microbial growth.
Base Number: Measure of alkaline additive content in a lubricating oil, expressed in milligrams of potassium hydroxide equivalent per gram of oil.
Base oil: Mineral or synthetic stock from which lubricants are formulated.
Bearing oil: Lubricant for plain or rolling element bearings, often supplied from the system oil circuit on marine engines.
Bench overhaul: Workshop reconditioning of components such as fuel pumps and injectors that depends in part on clean system oil during prior service.
Biodegradable lubricant: Oil formulated to degrade rapidly in the aquatic environment, qualifying as an Environmentally Acceptable Lubricant under the US Vessel General Permit.
Biostability: Resistance of a lubricant to attack by bacteria and fungi during storage and service.
Blending plant: Facility where base oils and additive packages are combined to produce finished marine lubricants for bunker supply.
BN depletion: Reduction of Base Number in service as alkaline additives are consumed by acid neutralization and oil drainage.
BN reserve: Remaining Base Number in a used cylinder oil sample relative to the fresh oil specification.
Bore polishing: Mirror-smooth wear pattern on a cylinder liner that reduces oil retention and accelerates ring wear.
Bottom end bearing: Connecting rod big-end bearing supplied with system oil under pressure in a four-stroke or crosshead engine.
BP Energol CLO 50M: BP Marine cylinder lubricating oil for crosshead two-stroke diesel engines burning residual fuel.
BP Marine: Marine lubricants division of BP that markets the Energol and, through Castrol Marine, Cyltech and CDX product families.
Bright stock: High-viscosity solvent-refined base stock historically used as a thickening component in residual-fuel cylinder oils.
Bulk delivery: Supply of marine lubricant by tank truck or barge into ship storage tanks rather than in drums or IBCs.
Bunker port: Port where fuel and lubricants are routinely supplied to commercial shipping, often a hub for oil major distribution.
Bunker survey: Quantity and quality measurement at delivery and redelivery.

C

Calcium carbonate: Overbased detergent additive that provides alkaline reserve and acid neutralization capacity in cylinder oils.
Calcium sulfonate: Detergent additive widely used as a carrier of alkaline reserve and as a rust inhibitor in marine lubricants.
Carbon residue: Carbonaceous deposit remaining after evaporation and pyrolysis of a fuel, measured by Conradson, Ramsbottom, or micro methods.
Castrol Cyltech 100: Castrol Marine 100 BN cylinder oil for residual-fuel two-stroke crosshead engines.
Castrol Cyltech 140: Castrol Marine 140 BN cylinder oil for high-sulfur residual-fuel operation, typically on scrubber-fitted ships.
Castrol Cyltech 50: Castrol Marine cylinder oil with 50 BN intended for two-stroke crosshead engines burning low-sulfur fuels.
Castrol Cyltech 70: Castrol Marine 70 BN cylinder oil for two-stroke engines operating on intermediate sulfur fuels.
Castrol Cyltech 80: Castrol Marine 80 BN cylinder oil bridging low-sulfur and residual-fuel duty.
Castrol Marine: Marine lubricants brand within the BP group that supplies the Cyltech, TLX Plus, and CDX product ranges.
Castrol TLX Plus 304: Castrol Marine 30 BN trunk piston engine oil for medium-speed four-stroke engines on distillate or very low sulfur fuel.
Castrol TLX Plus 404: Castrol Marine 40 BN trunk piston engine oil for four-stroke engines burning intermediate fuel oils.
Castrol TLX Plus 504: Castrol Marine 50 BN trunk piston engine oil for four-stroke engines burning higher sulfur residual fuel.
Cat fines: Aluminosilicate catalyst particles from refinery FCC units, abrasive to liners, rings, and fuel pumps.
Cepsa: Spanish energy company that supplies marine lubricants and bunker fuels in Iberian and selected international ports.
Cepsa Marine: Marine business unit of Cepsa providing cylinder, system, and auxiliary lubricants.
Chevron Delo: Heavy-duty engine oil brand from Chevron, with selected grades used in marine auxiliary and stern tube applications.
Chevron Marine Products: Marine lubricants division of Chevron that markets the Taro and Veritas families.
Chevron Taro Special HT 100: Chevron 100 BN cylinder oil for two-stroke crosshead engines on residual fuel.
Chevron Taro Special HT 70: Chevron 70 BN cylinder oil for two-stroke crosshead engines on intermediate sulfur fuel.
Chevron Taro Special HT LF 100: Chevron low-feed-rate 100 BN cylinder oil for two-stroke crosshead engines.
Chevron Taro Special HT LF 140: Chevron low-feed-rate 140 BN cylinder oil designed for high-sulfur residual operation on scrubber-fitted vessels.
Chevron Taro Special HT LF 70: Chevron low-feed-rate cylinder oil with 70 BN for modern long-stroke two-stroke engines.
Chevron Veritas 800 Marine: Chevron trunk piston engine oil range for four-stroke medium-speed engines.
Chronic wear: Steady accelerated wear pattern indicated by persistently elevated iron content in scrape-down samples.
Cleveland open cup: Apparatus and method for measuring flash and fire points of lubricating oils per ASTM D92.
Cold cranking simulator: CCS apparatus measuring low-temperature apparent viscosity of crankcase oils, more relevant to automotive than marine grades.
Compatibility: Ability of two fuels to be mixed without precipitation of asphaltenes, assessed by spot test (ASTM D4740).
Compounded oil: Lubricant in which a base oil is treated with fatty oils or additives, historically used for steam cylinder service.
Compression ring: Top piston ring whose lubrication is most critical for combustion gas sealing and liner wear control.
Condition monitoring: Vibration, oil-analysis, and performance trending of machinery.
Conradson carbon: Residue test on fuel oil indicating coking tendency, reported on bunker analysis.
Copper corrosion: Tarnish test on a polished copper strip immersed in oil to assess corrosivity toward yellow metals.
Corrosive wear: Loss of metal from cylinder liners and rings caused by sulfuric acid attack when alkaline reserve is inadequate.
Cosmo Oil: Japanese refiner whose Cosmo Marine lubricant range serves domestic and international shipping.
Cost per running hour: Operating metric used by superintendents to compare lubricant performance across feed rates and grades.
Crankcase: Lower engine enclosure that holds the system oil sump and supplies pressure lubrication to bearings.
Crankcase explosion: Ignition of oil mist in the crankcase, mitigated by oil mist detection and explosion relief doors.
Crankcase oil: System oil that lubricates bearings, gears, and cooling galleries in a two-stroke crosshead engine.
Crosshead engine: Large two-stroke marine diesel with a separate guide for piston rod motion, allowing independent cylinder and system oil circuits.
Cylinder feed rate: Quantity of cylinder oil injected per unit of engine work, expressed in grams per kilowatt hour.
Cylinder lubricator: Mechanical or electronic device dosing cylinder oil through quills into the liner.
Cylinder oil: High-BN lubricant feeding the cylinder liners of two-stroke crosshead engines.
Cyltech 100: Castrol Marine 100 BN cylinder oil widely used on residual-fuel two-stroke engines.

D

Deck machinery oil: Hydraulic and gear oils used in winches, cranes, and hatch cover systems, typically ISO VG 32 to 220.
Deposit control: Function of detergent and dispersant additives that limit lacquer and carbon buildup on engine surfaces.
Detergent: Lubricant additive that neutralizes acidic combustion products and keeps deposits in suspension.
Diesel engine oil: General term covering both trunk piston engine oils and crankcase oils for compression-ignition engines.
Disola M 4015: Total Lubmarine 15 BN distillate-fuel diesel engine oil for medium-speed four-stroke engines.
Disola M 4020: Total Lubmarine 20 BN distillate-fuel diesel engine oil for high-speed and medium-speed engines on marine gas oil.
Dispersant: Chemical applied to oil spills to break oil into smaller droplets.
Distillate fuel: Fraction produced by atmospheric or vacuum distillation, including DMA, DMB, DMX, and DMZ grades.
Drain interval: Time or operating hours between system oil changes, extended by good condition monitoring.
Drain oil: Used oil scraped down from the cylinder liner of a two-stroke engine, analyzed to monitor wear and BN reserve.
Drip lubrication: Lubrication method delivering oil by gravity feed, used historically on some auxiliary equipment.
Dynamic viscosity: Absolute viscosity of a fluid expressed in pascal seconds or centipoise.

E

EAL: Environmentally Acceptable Lubricant qualifying for use in oil-to-sea interfaces of vessels subject to the US Vessel General Permit and Vessel Incidental Discharge Act.
Effective alkalinity: Portion of Base Number that is actually available to neutralize combustion acids under engine operating conditions.
Eneos: Japanese petroleum brand under Eneos Holdings that markets marine lubricants including the Marine and Mariner ranges.
Eneos Marine: Marine lubricant line of Eneos Corporation, formerly part of JX Nippon Oil and Energy.
Environmental compliance: Adherence to MARPOL, VGP, VIDA, and similar regulations governing fuel sulfur and oil discharges.
Ester base stock: Synthetic base oil derived from organic acids and alcohols, used in many biodegradable marine lubricants.
ExxonMobil Marine: Marine fuels and lubricants business of ExxonMobil that markets the Mobilgard family.
ExxonMobil Mobilgard 300: Mobil cylinder oil with 70 BN historically used on two-stroke crosshead engines burning residual fuel.
ExxonMobil Mobilgard 300C: Mobil cylinder oil with 70 BN designed for category II engines operating on intermediate sulfur fuels.
ExxonMobil Mobilgard 540: Mobil 40 BN cylinder oil for two-stroke engines on low-sulfur fuels.
ExxonMobil Mobilgard 570: Mobil 70 BN cylinder oil for two-stroke engines on intermediate sulfur fuels.
ExxonMobil Mobilgard HPS: Mobil 100 BN cylinder oil for two-stroke engines on high-sulfur residual fuel.
ExxonMobil Mobilgard HPS Plus: Mobil cylinder oil with elevated BN engineered for high-sulfur residual-fuel operation on scrubber-fitted ships.

F

FAMM: Fuji Kosan and JX Nippon joint marine lubricant arrangement, supplying lubricants under recognized regional brands in Japanese waters.
Feed rate optimization: Systematic adjustment of cylinder oil injection quantity to balance wear protection and lubricant consumption cost.
Filtration: Removal of particulate contaminants from system oil using full-flow and bypass filters of specified beta ratio.
Fire point: Lowest temperature at which a fuel sustains burning after ignition.
Flash point: Lowest temperature at which fuel vapor ignites with a pilot flame; minimum 60 C for SOLAS marine fuels (Pensky-Martens closed cup, ISO 2719).
Fluidity: Inverse of viscosity, describing the ease with which a lubricant flows at a given temperature.
Foam test: Sequence I, II, and III foaming tendency and stability measurement per ASTM D892.
Four-stroke engine: Otto/Diesel cycle engine with separate intake, compression, power, exhaust strokes.
FT-IR analysis: Fourier transform infrared spectroscopy used to identify oxidation, nitration, sulfation, water, and fuel dilution in used oils.
Fuchs Marine: Marine lubricants line of Fuchs Petrolub serving deep sea and coastal fleets with the Titan and Renolin product families.
Fuel dilution: Contamination of system oil by unburned fuel, indicated by lowered flash point and reduced viscosity.

G

Gear oil: Lubricant formulated with extreme pressure additives for reduction gearboxes and steering gear drives.
Glycol contamination: Coolant ingress into lubricating oil, confirmed by analytical glycol testing.
Graphite grease: Grease containing colloidal graphite for shock-loaded slow speed plain bearings.
Gravity feed: Lubrication method relying on oil head pressure rather than positive pumping.
Grease NLGI 2: General purpose lithium or lithium complex grease of consistency Number 2 per the National Lubricating Grease Institute scale.
Group I base oil: Solvent-refined mineral base oil with less than 90 percent saturates and more than 0.03 percent sulfur.
Group II base oil: Hydroprocessed mineral base oil with greater than 90 percent saturates and lower sulfur than Group I.
Group III base oil: Severely hydroprocessed mineral base oil with viscosity index above 120, marketed as synthetic in many jurisdictions.
Group IV base oil: Polyalphaolefin synthetic base stock.
Group V base oil: Any base stock not falling into Groups I through IV, including esters, polyalkylene glycols, and naphthenics.
Gulf Oil Marine: Marine lubricants supplier with the GulfSea range of cylinder, system, and trunk piston engine oils.

H

Hans Jensen Lubricators: Danish manufacturer of cylinder lubrication systems including the Swirl Injection Principle and Pulse Lubrication System.
HFO: Heavy fuel oil, residual marine fuel grade per ISO 8217 RMG and RMK.
HFRR test: High Frequency Reciprocating Rig wear scar measurement, primarily a fuel lubricity method but referenced in oil studies.
High BN cylinder oil: Cylinder lubricant with Base Number of 100 or above formulated for high-sulfur residual fuel operation.
High Performance Series: ExxonMobil Mobilgard HPS designation for cylinder oils targeting residual-fuel two-stroke engines.
HSFO: High sulfur fuel oil with sulfur content above 0.5 percent, permitted on ships fitted with compliant exhaust gas cleaning systems.
HV hydraulic oil: ISO grade hydraulic fluid with shear stable viscosity index improver per ISO 6743-4 type HV.
Hydraulic oil HM: Antiwear hydraulic fluid per ISO 6743-4 type HM, with rust, oxidation, and antiwear additives.
Hydraulic oil ISO VG 32: Hydraulic fluid with kinematic viscosity of 32 mm squared per second at 40 degrees Celsius.
Hydraulic oil ISO VG 46: Hydraulic fluid with kinematic viscosity of 46 mm squared per second at 40 degrees Celsius, common in shipboard service.
Hydraulic oil ISO VG 68: Hydraulic fluid with kinematic viscosity of 68 mm squared per second at 40 degrees Celsius, used in higher temperature systems.
Hydrocracked base oil: API Group II or III base stock produced by hydrocracking and dewaxing of vacuum gas oil.

I

ICP-OES: Inductively coupled plasma optical emission spectrometry, used for trace metals.
Idemitsu Daphne Marine: Marine lubricant range from Idemitsu Kosan covering cylinder, system, and auxiliary oils.
Idemitsu Kosan: Japanese refiner whose Daphne Marine and Apolloil ranges include marine cylinder, system, and trunk piston engine oils.
IMO 2020: 0.50% sulfur cap on marine fuels; not a GHG measure but driving fuel mix changes.
In-service oil: Lubricant sample drawn from operating equipment for condition monitoring analysis.
Induction lubrication: Concept describing the controlled introduction of oil into the combustion chamber by timed injection.
Inhibited oil: Lubricant containing rust and oxidation inhibitors, common in turbine and hydraulic services.
Initial fill: Lubricant charge supplied by the engine builder for the first running period of a new engine.
Injection quill: Tube and check valve assembly through which cylinder oil is delivered to the liner from the lubricator.
Iron content: Concentration of iron in scrape-down or system oil samples, used as a primary wear indicator.
ISO 3448: International Organization for Standardization classification of industrial lubricant viscosity grades.
ISO 6743: Family of standards covering classification of lubricants by application.
ISO VG: ISO viscosity grade designating kinematic viscosity at 40 degrees Celsius.

J

JX Nippon TonenGeneral Mobilgard: Joint distribution arrangement historically supplying ExxonMobil Mobilgard cylinder oils in Japanese waters.

K

Kinematic viscosity: Ratio of dynamic viscosity to density, expressed in cSt; ISO 8217 specifies viscosity at 50 C for residuals and at 40 C for distillates.
Klueber: Specialty lubricant manufacturer under Freudenberg supplying greases, gear oils, and chain lubricants for marine and industrial use.
Klueber Klueberoil: Industrial gear oil range from Klueber used in selected marine reduction gear applications.
Klueber Klueberplex: Klueber grease line for heavily loaded plain and rolling element bearings.

L

Lacquer: Single-pack solvent-evaporating coating, used historically for furniture and decorative trim and rarely for hull work.
Lapping: Liner running-in process during which controlled cylinder oil feed develops the wear pattern that supports long-term ring sealing.
LDL: Load Dependent Lubrication, a control strategy that scales cylinder oil feed rate to engine load.
Liner: Vessel operating to a published schedule on a fixed route.
Liqui Moly Marine: Marine line of Liqui Moly additives and oils, marketed for leisure and small commercial vessels.
Liquidity: Term loosely used in lubrication context to mean fluidity at a given temperature.
Lithium complex grease: Grease using a lithium complex thickener offering high dropping point and water resistance.
Low BN cylinder oil: Cylinder lubricant with Base Number between 25 and 40 formulated for very low sulfur fuel operation.
Lubrication regime: Operating state of a tribological contact, classified as boundary, mixed, or hydrodynamic.
Lukoil Marine Lubricants: Marine lubricant supplier within the Lukoil group, with the Navigo and Meta range.
Lukoil Navigo MCL 4070: Lukoil 70 BN cylinder oil for two-stroke crosshead engines on intermediate sulfur fuels.
Lukoil Navigo TPEO 5050: Lukoil 50 BN trunk piston engine oil for four-stroke medium-speed engines.
Lukoil Navigo TPEO 55 BN 100: Lukoil trunk piston engine oil with 55 BN designed for four-stroke engines on higher sulfur fuels.

M

MAN ME-B: MAN Energy Solutions electronically controlled two-stroke engine variant using mechanical fuel pumps and an electronic exhaust valve, served by Alpha Lubricator.
MAN ME-C: Fully electronically controlled MAN Energy Solutions two-stroke engine equipped with Alpha Lubricator cylinder oil injection.
Manual lubricator: Operator-actuated grease gun or oil can used for routine point lubrication of deck and engine room machinery.
MARPOL Annex VI: Air pollution and energy-efficiency annex.
MCC: Mean cylinder condition assessment based on scrape-down sampling, inspection, and feed-rate optimization.
MEPC.359(78): International Maritime Organization resolution that adopted amendments to MARPOL Annex VI relating to sulfur fuel and related operational provisions.
Mobilgard 1 SHC: ExxonMobil fully synthetic high performance crankcase oil for medium-speed engines requiring extended drain intervals.
Multigrade oil: Engine oil meeting two SAE viscosity grades, used in selected marine auxiliary and stern tube duties.

N

Naphthenic base oil: Mineral base stock high in naphthenes, valued for low pour point in refrigeration and selected marine applications.
Neutralization reserve: Capacity of an oil to neutralize residual acidic combustion products, measured as Base Number.
NLGI 0: National Lubricating Grease Institute grade 0 designating a soft semifluid grease.
NLGI 1: NLGI grade 1 grease, softer than the general purpose NLGI 2.
NLGI 2: NLGI grade 2 grease, the most common consistency for marine deck machinery and electric motor bearings.
NLGI 3: NLGI grade 3 grease, used where dripping must be minimized.
NLGI EP2: Common shorthand for an extreme pressure grease of NLGI consistency 2.
Noack volatility: Mass loss of oil at 250 degrees Celsius over one hour per ASTM D5800, indicating evaporative tendency.

O

OEM approval: Engine builder endorsement issued after testing that confirms a lubricant meets stipulated performance for a given engine series.
OEM specification: Lubricant performance requirement issued by an engine manufacturer such as MAN Energy Solutions or WinGD.
Oil analysis program: Structured sampling and laboratory testing service for monitoring lubricant and equipment health.
Oil consumption: Quantity of cylinder or system oil used per unit time or per unit fuel burned by an engine.
Oil mist detector: OMD continuously monitoring crankcase atmosphere, types include Schaller Visatron VN 116/87 and Specronix.
Optimization study: Engineering review of cylinder oil feed rate, BN selection, and fuel sulfur to minimize wear and operating cost.
Overbased detergent: Detergent additive carrying excess metal carbonate to deliver high Base Number in a small treat rate.
Overfeed: Cylinder oil injection rate above the optimum required for wear control, increasing operating cost and deposit formation.
Oxidation: Reaction of base oil hydrocarbons with oxygen at elevated temperature, leading to viscosity rise and acid formation.

P

PAO: Polyalphaolefin, a Group IV synthetic base stock with high viscosity index and low pour point.
Pensky-Martens closed cup: Reference flash point apparatus for ISO 2719, ASTM D93, and IP 34 tests.
Petrobras Lubrax: Marine lubricants brand of Petrobras Distribuidora supplying cylinder, system, and auxiliary oils in Brazilian and selected international ports.
Petromin: Saudi lubricants manufacturer with marine product lines for regional shipping.
Phosphorus content: Concentration of phosphorus in lubricant, typically from antiwear additives, monitored by ICP-OES.
Pintle nozzle: Older injector design that has shaped marine cylinder lubrication research on spray distribution.
Piston ring: Sealing ring fitted in a piston groove that relies on cylinder oil for friction and wear control.
PLS: Pulse Lubrication System developed by Hans Jensen Lubricators for accurate timed cylinder oil injection.
Polyalkylene glycol: Group V synthetic base stock used in selected biodegradable and high-temperature lubricants.
Polyol ester: Saturated synthetic ester used in many EAL hydraulic and stern tube oils.
Pour Point: Lowest temperature at which oil flows; key to heating decisions.
Pulse Jet: Hans Jensen injector technology delivering atomized cylinder oil pulses into the combustion chamber.
Pump element: Internal cylinder lubricator component that meters oil per stroke to a quill.
Purifier: Centrifuge with water seal removing free water and solids from fuel oil.

Q

Q8 Mahler: Q8Oils cylinder oil line for two-stroke crosshead engines.
Q8 Mozart: Q8Oils trunk piston engine oil line for medium-speed engines.
Q8Oils: Marine and industrial lubricants brand of Kuwait Petroleum International serving global shipping.
Quench oil: Heat-treatment oil unrelated to marine lubrication but sometimes referenced in shipyard contexts.
Quill: Tube delivering cylinder oil from lubricator to the liner.

R

Rancimat: Oxidation stability test apparatus used for selected biodegradable lubricants.
RDE: Rotating Disc Electrode atomic emission spectrometry used for wear metals per ASTM D6595.
Refractive index: Optical property occasionally used to screen for gross contamination in used oils.
Repsol Marine: Marine lubricants line of Repsol with cylinder, system, and auxiliary product ranges.
Residual fuel: Heavy residual marine fuel grades RMG/RMK.
Ring pack: Set of compression and oil control rings fitted to an engine piston, whose sealing depends on adequate cylinder lubrication.
Rotating Disc Electrode: Spectroscopic technique that vaporizes a sample film for elemental analysis without acid digestion.
Rust inhibitor: Additive that protects ferrous surfaces from corrosion in the presence of water and oxygen.

S

SAE 30: Single grade engine oil with kinematic viscosity at 100 degrees Celsius between 9.3 and 12.5 mm squared per second.
SAE 40: Single grade engine oil with kinematic viscosity at 100 degrees Celsius between 12.5 and 16.3 mm squared per second.
SAE 50: Single grade engine oil with kinematic viscosity at 100 degrees Celsius between 16.3 and 21.9 mm squared per second.
SAE J300: Society of Automotive Engineers standard for crankcase oil viscosity grades.
Sample bottle: Compliant glass or amber HDPE container for bunker samples, sealed with tamper-evident closure and uniquely numbered.
Scavenge space: Section of a two-stroke engine where exhaust gas is replaced by fresh charge air and where cylinder oil residues collect.
Scrape-down analysis: Laboratory testing of oil collected from the scavenge space to monitor wear metals, BN reserve, and contamination on two-stroke crosshead engines.
Scrubber-fitted ship: Vessel equipped with exhaust gas cleaning system that may legally burn high-sulfur residual fuel, typically using high BN cylinder oil.
Seal compatibility: Property of a lubricant to coexist with elastomer seals without excessive swelling, shrinkage, or hardening.
Shell Alexia 200: Shell Marine 100 BN cylinder oil for two-stroke crosshead engines on high-sulfur residual fuel.
Shell Alexia 240: Shell Marine cylinder oil with 140 BN formulated for high-sulfur residual fuel operation on scrubber-fitted ships.
Shell Alexia 40: Shell Marine 40 BN cylinder oil for two-stroke engines on low-sulfur fuels.
Shell Alexia 50: Shell Marine 50 BN cylinder oil bridging low and intermediate sulfur duty.
Shell Alexia S3: Shell Marine cylinder oil engineered for two-stroke crosshead engines burning intermediate sulfur fuel.
Shell Alexia S4: Shell Marine 60 BN cylinder oil for two-stroke crosshead engines.
Shell Alexia S5: Shell Marine cylinder oil formulated for high-sulfur residual-fuel two-stroke engines.