One of a ship's engineering crew. Often a crewman responsible for maintaining a Steam donkey, or any machinery other than the main engines. On some ships, the Petty Officer in charge of engine room ratings.

Related Terms

CROWN

The top of the piston in an internal combustion engine above the fire ring, exposed to direct flame impingement.

RETURN-STEAM CONDENSATE

That steam produced by a boiler which returns to the boiler after it has condensed.

DEPOSITS

Oil-insoluble materials that result from oxidation and decomposition of lube oil and contamination from external sources and engine blow-by. These can settle out on machine or engine parts. Examples are sludge, varnish, lacquer and carbon.

ADIABATIC EFFICIENCY

The ratio of actual work output of a heat engine to the ideal output.

API ENGINE SERVICE CATEGORY

Gasoline and diesel engine oil quality levels established jointly by API, SAE, and ASTM, and sometimes called SAE or API/SAE categories; formerly called API Engine Service Classifications.

ELECTROSTATIC SEPARATOR

A separator that removes contaminant from dielectric fluids by applying an electrical charge to the contaminant that is then attracted to a collection device of different electrical charge.

BORE POLISHING

Excessive smoothing of the surface finish of the cylinder bore or cylinder liner in an engine to a mirror-like appearance, resulting in depreciation of ring sealing and oil consumption performance.

POLAR COMPOUND

A chemical compound whose molecules exhibit electrically positive characteristics at one extremity and negative characteristics at the other. Polar compounds are used as additives in many petroleum products. Polarity gives certain molecules a strong affinity for solid surfaces; as lubricant additives (oiliness agents), such molecules plate out to form a tenacious, friction- reducing film. Some polar molecules are oil-soluble at one end and water-soluble at the other end; in lubricants, they act as emulsifiers, helping to form stable oil-water emulsions. Such lubricants are said to have good metal-wetting properties. Polar compounds with a strong attraction for solid contaminants act as detergents in engine oils by keeping contaminants finely dispersed.

LIVE STEAM

Steam which has not performed any of the work for which it was generated.

VISCOSITY GRADE

Any of a number of systems which characterize lubricants according to viscosity for particular applications, such as industrial oils, gear oils, automotive engine oils, automotive gear oils, and aircraft piston engine oils.

Related questions

MarineProHelp 2018 - 2022