Technology and the built world

Presidente Médici Candiota power station

The Presidente Médici Candiota power station, also called Candiota II, is a coal-fired power station in Candiota, Rio Grande do Sul, Brazil, built between 1974 and 2011.

Presidential dollar coins

Presidential dollar coins are a series of United States $1 coins issued by the U.S. Mint from 2007 to 2016, bearing portraits of American presidents in the order served.

Presidential state car (United States)

The presidential state car of the United States, nicknamed The Beast or Cadillac One, is the Secret Service's heavily armored Cadillac-styled limousine for the president.

Press-hardened steel, also called hot-stamping steel, is a boron-alloyed sheet steel, most commonly 22MnB5, formed hot and quenched in dies to reach about 1500 MPa, widely used in car body reinforcements.

Pressboard

Pressboard, also known as transformerboard, is a high-density cellulose board used as electrical insulation in oil-filled power transformers, serving as spacers, barriers, and clamping parts.

Pressure acid leaching

Pressure acid leaching (PAL), usually called high-pressure acid leaching (HPAL), extracts nickel and cobalt from lateritic ores with sulfuric acid in autoclaves at about 250 °C and 45–50 bar.

Pressure angle

The pressure angle of a gear is the angle between the line of action of the tooth force and the pitch circle tangent; standard values are 14.5°, 20°, and 25°.

Pressure compensator

A pressure compensator is a hydraulic control element that adjusts pump displacement or valve pressure drop to keep flow or pressure constant under changing loads.

Pressure cooker bomb

A pressure cooker bomb is an improvised explosive device made from a household pressure cooker filled with explosive and shrapnel, used in the 2013 Boston Marathon bombing.

Pressure leaching

Pressure leaching is a hydrometallurgical process in which ores are dissolved in a pressurized autoclave above boiling point, first commercialized in the Bayer process in 1892.

Pressure oxidation

Pressure oxidation (POX) is a hydrometallurgical process that oxidizes metal sulfides in a sealed autoclave at elevated temperature and oxygen pressure, used mainly to free gold occluded in refractory ores.

Pressure ratio

Pressure ratio is the ratio of total pressure at two stations of an engine or machine, quantifying how much a compressor or whole engine raises the pressure of the gas flow.

Pressure regulator

A pressure regulator, also called a pressure-reducing valve, is a mechanical device that holds gas or liquid pressure at a set value without external power.

Pressure retarded osmosis

Pressure retarded osmosis (PRO), also called osmotic power or blue energy, is a membrane process that generates electricity from the salinity difference between fresh water and pressurized salt water.

Pressure suppression pool

A pressure suppression pool is a pool of water inside a boiling water reactor's containment that condenses steam released during an accident, limiting containment pressure.

Pressure swing adsorption

Pressure swing adsorption (PSA) is a gas separation technique that regenerates its adsorbent by pressure reduction, used industrially for air separation, gas drying, and hydrogen purification.

Pressure swing distillation

Pressure swing distillation is a chemical engineering technique that separates homogeneous azeotropic mixtures by running two columns at different pressures, so pure products can be withdrawn without adding a solvent.

Pressure testing

Pressure testing is an engineering verification method that applies internal pressure, usually with water or gas, to vessels and piping to confirm strength and leak-tightness.

Pressure transient analysis

Pressure transient analysis (PTA) is a well testing method that interprets pressure changes measured in a well over time to estimate permeability, skin factor, and reservoir pressure.

Pressure vessel

A pressure vessel is a closed container designed to hold gases or liquids at pressures substantially different from ambient pressure, in applications from chemical plants to submarines.

Pressure-fed engine

A pressure-fed engine, also called a pressure-fed rocket engine, is a liquid rocket engine in which tank pressure, usually from helium, feeds propellants into the thrust chamber without a turbopump.

Pressure-gain combustion

Pressure-gain combustion is a combustion mode in which pressure rises across the combustor instead of falling, pursued to improve gas turbine efficiency since the 1950s.

Pressure-sensitive adhesive

A pressure-sensitive adhesive (PSA) is an adhesive that forms a bond when pressure is applied, without heat, solvent, or chemical reaction, used in tapes, labels, stamps, and bandages.

Pressure-sensitive tape

Pressure-sensitive tape, also called sticky tape or PSA tape, is a flexible strip coated with a tacky adhesive that bonds under light finger pressure, first made in 1845.

Pressureless sintering

Pressureless sintering is the densification of a powder compact by heating alone, with no external pressure, and is the dominant fabrication route for ceramic bodies.

Pressuremeter test

The pressuremeter test (PMT) is an in situ geotechnical test in which a probe with an expandable membrane is inflated in a borehole to derive soil strength and stiffness parameters.

Pressurized fluidized bed combustion

Pressurized fluidized bed combustion (PFBC) is a coal-fired power technology in which coal burns under pressure in a combined steam and gas turbine cycle, commercialized in the 1990s.

Pressurized thermal shock

Pressurized thermal shock (PTS) is a pressurized water reactor event combining severe overcooling of the reactor pressure vessel with high pressure, threatening vessels embrittled by neutron irradiation.

Pressurized water reactor

A pressurized water reactor (PWR) is a nuclear reactor in which water held at high pressure serves as coolant and moderator, the most common reactor type worldwide at about 65% of operating power reactors.