Document Vn14xKV25d1mEVDZDqV0o6vg

966 CHAPTER 68 Tens Text Blowings effective horsepower........................... efficiency.............................................. eff electromotive force............................. emf equivalent direct radiation................ evaporat(e) (-in$ -ed, -or)................................. expansion valve.................................. edr ECON EHP EFF EMF EDR EVAP EXP VLV face-to-face.................... factor of safety.............. feet per minute. .1___ feet per second.................................... foot................... ............ .................. . .-. *' fpm ft F to F F/S ' FPM FPS FT foot pound........................................... foot-pound-second (system)............ freezing point...................... ........ gage or gauge..................................... gallon................................................... ft ib fp ga gal FT LB FPS FP GA GAL gailfm* per hour................................. gph GPH g-ftllnna pgj minnt.................................... gpm GPM gallons per second.............................. . gpa GPS grain..................................................... spell out ... gram-calorie............... .................... gcal GCAL higher value........................... horsepower..'....................................... horsepower-hour................................. hour..................................................... inch...................................................... HHV : hphr hrj'. in. - HP HPHR HR IN. inch-pound.......................................... indicated horsepower......................... indicated horsepower-hour................ inside diameter................................... iron-pipe size....................................... in.-lb ibp ihph ID ips IN.-LB IHP IHPH ID IPS kilocalorie............................................ kcal kilogram..................... ...................... kg kilowatt...................... ...................... kw kilowatt hour...................................... linear feet.:!....................................... lin ft KG KW KWH liquid.. ............................................. logarithm (natural)............................ logarithm (to.base 10)....................... lower heating value............................ maintenance........................................ liq log. LHV LIQ MAINT mwU> and female................................. nuiTiTnim...................................................... mean effective..................................... melting point...................................... mass' max mep mp M&F MASS MAX MEP - MP meter................................................... meters per second............................... micron.................................................. miles per hour..................................... milini>>ia........................................................ m mps - mph . mi M MPS U(MU) MPH . MI millinWor...................................................... minute....:....................................... minimum....................................................... molecular weight... ....................... mol............ 1........................................ mm min * min mo) wt mol MM .MIN." MIN . MOL WT MOL National Electrical Code................... number....................... ......................... ounce................................................... outside diameter................................. parts per million.............. ................ no. os OD ppm NEC NO. oz OD PPM pound.......... ........................................ pounds per .square foot...................... `pounds per square foot absolute... pounds per square foot gage............ pounds per square inch.,.'............. Ib psf psfa psfg psi .". LB PSF PSFA PSFG par 19.65 Guide And Data-Book Texf Drawing* pounds per square inch absolute.... pounds Der sauara truth ram> pneumatic............................................ pressure............................................... psia Prig press. PSIA PSIG PNEU PRESS. pressure reducing valve...................... quart.................................................... receiver................................................ rearculate(d)...... ............................ qt PRV QT REC RECIRC relative humidity....\ . .............. required............................................... revolution............................................ revolutions per minute....................... revolutions per second........................ rpm rpo RH REQD REV RPM BPS' Saybolt seconds Furol (oil viscosity). Saybolt seconds Universal (oil viscosity)............. second..................... .......................... shaft horsepower................................. SSF SSU sec shp SSF SSU SEC SHP. specification......................................... specific gravity................................... specific heat................................... square................................................... square foot........................................... sp ht aq ft SPEC SP GR SP HT SQ square inch.......................................... standard............................................... suction....................................... ....... '. temperature......................................... sq in. std temp STD SUCT ' TEMP thermostat........................................... thousand.............................................. ton.................................. .................. thousand cubic feet............................ THERMO MM spell out Mcf MCF ton of refrigeration...... .................... United States Gage............................ United States Standard..................... vacuum................................................ tr USG uss TR USG USS VAC valve........................... ...................... vapor proof................................ velocity................................................ viscosity............................................... vel vise V VAP PRF VEL vise volume................................................. watt...................................................... watthour.............................................. wet-bulb temperature........................ year....................... ............................ w whr wbt yr VOL W WHR WBT YR LETTER SYMBOLS** 1. Letter Symbol. A letter symbol is a angle character, such as t for temperature, with subscript or superscript if required, such as tf for temperature of saturated liquid, used to desig nate a physical magnitude in mathematical equations and ex pressions. Two or more symbols together always represent a product Letter symbols are to be distinguished from abbreviations, mathematical signs and operators, graphical symbols and chemical symbols. 2. The Same Symbols should be used for the some physical magnitude regardless of the units employed and regardless of special values occurring for different states, points, parts, times, etc. Units or special values may be distinguished when necessary by subscripts, superscripts, or by upper- and lower- 1 Latter Symbol* for Mechanic# erf Solid Bodice, Z103-lM8,eod Letter Sym bols for Heat mod Tto-iwipwwU, Y10.4-1857 (American Standard* Aeeoc*- p. 878). Abbreviations and Symbols case letters when both are specifically included as symbols in a standard list. The units used should be indicated when necessary. Sometimes different symbols are used for the com ponents of a vector. 3. Subscript A subscript preferably should be a single char acter. It is commonly employed to indicate constancy of a particular physical magnitude, such as pressure or tempera ture, when there are other variables. A' multiple subscript, sometimes divided by a comma, refers'to more than one state* point, part, time, etc. A subscript should not be at tached to' a subscript. 4. Superscript. A symbol with a superscript, such as a prime (0 or a second ('0, should be enclosed in parentheses, braces, or brackets before affixing an exponentr-^e.g.-- (/)'). A complicated exponent (or any other' expression fre quently repeated) may be replaced by a angle symbol selected to represent it..Reference marks should not be attached.to symbols. ... - 5. Unlisted Magnitudes. To symbolize.a special value of a listed magnitude, see Item 4. The symbol chosen by an author for a physical magnitude not appearing in any standard list should be one that does not already have a different meaning in the field of the text. 6. When standard symbols in related fields are needed, reference to ASA standards is recommended:. Letter Symbols for Heat and Thermodynamics, ASA Y10.4-1957 Letter Symbols for Hydraulics, ASA Y10.2-1958 . Letter Symbols for Chemical Engineering, ASA Y10.12- 1955 ,' Letter Symbols for Mechanics of Solid Bodies, ASA Z10.3- 1948 . `- Letter Symbols for. Physics, ASA Z10.6-1948 Additional symbols and variations in the standard symbols found necessary in the individual chapters will be found-in lists at the end of Chapters 2, 3, 4, 6, and 27. lime symbois 5ymbo/ D**crrpf/on ot Horn Typical onffs tt ir spoee thermal conductance Btu per (hr)(sq ft)(F) o acceleration. linear ft per (sac)(Kc) A area q ft b breadth or width ft B barometric pressure psia or in. Hg e specific beat Btu pa (lb)(F) specific heat at constant premie Btu per (lb)(F] specific heat at eonstaat volume Btu per (IbKF) Ce c c. coefficient of performance coefficient thermal conductance, surface to surface Btu per (hr)(aq ft)(F) d pidU indicating differential D /IlkrTula, ft i base ol natural logarithms B piwigy * Btu, Btu per Ib, ft-lb Bi ... internal ends' Btu, Btu per Q>, ft-lb* Bt . kinetic energy Btu, Btu pa Ib, ft-lb Bp potential energy Btu, Btu per D>, ft-lb B electrical potential volte f hnt t.pin<fw nvITMnt thmrtrH film film conductance Btu per (hr).(sq ft) (F) (d friction factor, D'Arcy-Wciabecb formu- lation tr friction footer; Fanning formulation P fores Ib Pa eoafiguration factor la radiant beat Pm q h k' V - A* - emlssxvity In radiant beat transfer ;. . .. gravitational acceleration ft per (eeel (seel specific enthalpy hvilrtnllrt lu1 heat transfer coefficient Btu per Ib ft . Btu' per (hrKoq ft)(F) specific enthalpy of dry air . Btu per Ib'dry air convection heat transfer Btu per (hr)(sq U)(F) 967 Symbol - Desertplica ot Hoot .._ Typictrf Bijh-'...,? ipeeiSt enthalpy ot saturated liquid Vi specific enthalpy of evaporation A* enthalpy ot dry saturated vapor Btu per lb Specific enthalpy of saturated solid Btu per 0> radiation heat transfer coefficient Btu per (hr)Csq fi)(Fl enthalpy of saturated air based on dry air wright Btu per lb dry air enthalpy of air-vapor mixture, bused on wot bulb temperature Btu per tb dry air, uifina "beat content," enthalpy of mix ture minus enthalpy of liquid at adia-. an dry weight total enthalpy electric current equivalent of boat thermal conductivity . Btu per D>diy air . ft-lb per. Btu Btu per (brHsq It) (Fperft)or(Fperiu ) ratio of specific hcatecp/c* (- r* f gamma, Hi preferred) proportionality constant length hydraulic radius, flow cross aeetion divided by wetted perimeter exponent of polytropic expansion or rate of rotation cumber in general IfOr or Or Graabsf number * - Nor or Ot Grants number -- - Npr or Pr Prsndtl number " -- e or absolute pal, in. Hg, lb per aq ft partial pressure of dry air pai or in..Ha partial pressure of water vapor pm or in. Ug saturation pressure of pure water vapor pai or in. Hg power hp, ft-lb per scfl, watts heat transfer volumetrie flow rate Btu per hr. Btu per lb cu ft per see or efm latent heat transfer rate Btu per hr mnaibie bent transfer rate . Btu per hr heat transfer, total latent heat transfer gas oonstant thermal resistance absolute temperature unit specific entropy (often with sobseripts /.ft. series with enthalpy) (ft-lb) per Qb}(R) (hr)(sq ft)(F) per G < temperature (usually with a defining snbeeript) absolute temperature tegarithmie mean temperature differ- , Internal energy (often with snbeeript*/, fa, o, or i a* with enthalpy) , <. internal energy, total overall heat transfer ooeffidcut specific volume humid .volume - . ... volume, total linear velocity humidity ratio of moist air, weight of water vapor per unit weight of (to per, (hr)(*q ftKF) u ft per lb u ft per lb dry sir lb per lb dry air lb ft-lb, Btu _