Rocks & mirror
WÄRTSILÄ
Encyclopedia of Marine and Energy Technology

P

423 results

Pressure surge

marine

A sudden increase in the pressure of the liquid in a pipeline brought about by an abrupt change in flow velocity. The pressure surge may cause a rupture of the piping and an extensive oil spill.

Pressure swing absorption (PSA)

marine

The technology of inert gas production by the removal of oxygen from air used on LNG tankers.

Pressure-vacuum valve (P/V valve)

marine

A valve which keeps the tank over pressure or under pressure within approved, limits. P/V valve provides for the flow of the small volumes of vapour, air or inert gas mixtures caused by thermal variations in a cargo tank.

Pressurised hold system

marine

MacGREGOR’s patented ‘hold overpressure system’ is a way of maximising the weathertightness of hatch covers.

Pressurized heavy-water reactor

energy

A pressurized heavy-water reactor (PHWR) is a nuclear reactor that uses heavy water (deuterium oxide D2O) as its coolant and neutron moderator.

Pressurized water reactor

energy

A pressurized water reactor (PWR) is a type of light-water nuclear reactor.

Prevailing wind

energy

The most common direction or directions that the wind comes from at a location.

Preventive maintenance

energy

Preventive maintenance (PM) is a routine for periodically inspecting with the goal of noticing small problems and fixing them before major ones develop.

Prewash

marine

The mandatory wash of the cargo tanks prior to loading cargo.

Primary barrier of membrane containment system, primary membrane

marine

The inner element designed to contain the cargo when the cargo containment system includes two barriers, (IGC CODE).

Primary bridge navigational equipment/systems

marine

Equipment/systems essential for performance of primary bridge navigational functions: log, echo sounder, gyrocompass, radar, position-fixing system and electronic chart system.

Primary cell

energy

A battery (galvanic cell) that is designed to be used once and discarded, and not recharged with electricity and reused like a secondary cell (rechargeable battery).

Primary containment

energy

The primary containment system usually consists of a large metal and/or concrete structure (often cylindrical or bulb shaped) that contains the reactor vessel. The primary containment system is designed to withstand strong internal pressures resulting from a leak or intentional depressurization of the reactor vessel.

Primary energy

energy

Primary energy is an energy form found in nature that has not been subjected to any human engineered conversion process.

Primary members of the hull structure

marine

Floors and bottom girders, side stringers and web frames, deck transverses and deck girders, vertical webs and horizontal stringers on bulkheads. Primary members support secondary stiffeners.

Prime movers

energy

In an engine/generator set the engine is the prime mover.

Primer coat or ground coat (painting)

marine

The first coat of the coating system applied in the shipyard after shop primer application.

Probable reserves

energy

Probable reserves are volumes defined as "less likely to be recovered than proved, but more certain to be recovered than Possible Reserves".

Problem solving

energy

Problem solving consists of using generic or ad hoc methods in an orderly manner to find solutions to problems.

Process engineering

energy

Process engineering is the understanding and application of the fundamental principles and laws of nature that allow humans to transform raw material and energy into products that are useful to society, at an industrial level.

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