low pressuren.adj.
/ˌləʊ ˈprɛʃə/, U.S. /ˌloʊ ˈprɛʃər/ A. n.
A pressure lower than some standard pressure (stated or implied), esp. a condition of the atmosphere in which the pressure is below average (e.g. in a depression). Also: a particularly low degree of physical pressure.
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the world > the earth > weather and the atmosphere > movements and pressure conditions > [noun] > atmospheric pressure > area of low pressure
low pressure1875
low1878
depression1881
1806 Retrospect Philos., Mech., Chem., & Agric. Discov. 1 234 A number of small boilers on the common construction, worked at the usual low pressure,..could be re-placed singly, if damaged.
1875 Encycl. Brit. III. 33 Areas of low pressure or Cyclones.
1899 G. D. Hiscox Mech. Movements vii. 153 Hydraulic intensifier.—High pressure obtained from low pressure by differential pistons.
1924 Jrnl. Amer. Chem. Soc. 46 1209 (heading) A receiving apparatus for practical distillation at low pressures.
1961 M. G. Say Electr. Engineer's Ref. Bk. (ed. 10) xii. 23 A flash discharge tube comprises a tube of hard glass or quartz, filled with a rare gas at low pressure.
2010 New Scientist 28 Aug. 35/2 That year saw a build-up of high pressure over the Beaufort Sea and a trough of low pressure over northern Siberia.
B. adj. Usually hyphenated.
1.
a. Designating engines and boilers using steam at low pressure; of, relating to, or used in engines and boilers of this kind.
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society > occupation and work > equipment > machine > machines which impart power > boiler > [adjective]
low pressure1816
tubular-flued1840
multitubular1849
tubulous1860
Field1865
Stirling1889
double-flued1895
1816 Encycl. Londinensis XIV. 785/2 Mr. Woolf's method is only applicable to low-pressure engines.
1817 New Monthly Mag. Sept. 128/1 Are those [steamboats] that are now constructing upon the high or low pressure system ?—Upon both.
1829 N. Arnott Elements Physics II. 94 The high-pressure or condensed steam..expands..until it becomes low-pressure steam.
1838 Mech. Mag. 13 Oct. 27/1 A boat fitted with such boilers, and Hall's or some other system of surface condensation, would be even safer than a boat fitted with low-pressure boilers.
1851 Official Descriptive & Illustr. Catal. Great Exhib. II. 213 Self-acting..damper, for high and low pressure steam.
1929 T. M. Naylor Steam Turbines i. 9 Mixed pressure turbines use both high-pressure and exhaust or low-pressure steam.
1965 D. J. Boorstin Americans xiv. 100 The high-pressure engine, compared to the low-pressure engine, was far lighter in proportion to horsepower.
2001 Oxoniensia 65 151 A low-pressure steam, or gravity return system, run by two large Cornish boilers in the basement heated many of the rooms and corridors by radiators.
2006 R. McDowall Fund. Hvac Syst. x. 136 The safety-equipment requirement and staff-monitoring requirements are far less stringent for low-pressure boilers.
b. Meteorology. Characterized by a low atmospheric pressure.
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1873 Daily Bull. Weather-rep. (U.S. War Dept.) 27 It has been supplied to the in-drawing low pressure area, or aerial hollow in the Northwest, by the southerly winds.
1876 W. H. Rosser Law of Storms 83 From the high pressure region of Central Asia the N.E. monsoon blows towards the low pressure area.
1906 Westm. Gaz. 23 Apr. 6/2 A shallow low-pressure system covers Scandinavia.
1967 Bull. Entomol. Res. 57 370 This convergence takes place within the low-pressure belt of the Doldrums, or the Equatorial Trough.
2005 A. Burdick Out of Eden (2006) xx. 264 At this time of year, a menacing low-pressure system..regularly races across the northern Pacific from Kamchatka to North America.
c. gen. Characterized by a low physical pressure; involving a small or limited degree of physical pressure.
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1897 T. C. Allbutt et al. Syst. Med. IV. 564 Those exceptional cases of Bright's disease, in which a low-pressure pulse is found.
1949 Our Industry (Anglo-Iranian Oil Co.) (ed. 2) ii. 33 In low-pressure wells, the upper section of the smaller diameter casing, the ‘oil string’, is sometimes removed as a measure of economy.
1969 E. P. Anderson Home Appliance Servicing (ed. 2) xxvii. 497 The remainder of the liquid and the low-pressure gas pass through a differential pressure-control valve.
2011 L. Porter Land Rover Series III Reborn vi. 221 (caption) A low-pressure pipe goes from the reservoir to the pump.
2. Characterized by a low electrical voltage (cf. pressure n.1 7). Now rare.
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1890 Electr. Engineer 14 Feb. 124/1 A low-pressure current will be used, with storage batteries, 100 volts at the houses.
1910 Central Electric Light & Power Stations, 1907 (U.S. Bureau Census) 191 The secondary coil takes the small-quantity high-pressure current from the primary coil and transforms it into large-quantity low-pressure current for use in the lamps, motors, etc.
1924 Pop. Sci. Monthly Aug. 41/2 A combination transformer and converter, that changes ordinary low-pressure alternating current into high-pressure direct current.
3. Involving a low level of exertion, difficulty, or responsibility; not likely to cause stress or anxiety; undemanding.
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1956 Life 9 Apr. 116/2 (caption) Tom Rath, satisfied with his low-paying and low-pressure job, agrees to move into flossy home they inherited.
1991 M. Mackie Gender Relations Canada viii. 214/1 New York consultant Felice Schwartz argued that companies should place these women on a special lower-paid, low-pressure career track.
2013 Daily Mirror (Nexis) 4 June (Ireland ed.) 45 As debuts go, it could hardly have been a more low-pressure environment.
This entry has been updated (OED Third Edition, September 2013; most recently modified version published online March 2022).
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n.adj.1806