This preview shows page 1. Sign up to view the full content.
Unformatted text preview: CHAPTER 37 ABBREVIATIONS AND SYMBOLS
Abbreviations for Text, Drawings, and Computer Programs ....................................................... 37.1 Letter Symbols ............................................................................................................................... 37.1 Dimensionless Numbers ................................................................................................................ 37.4 Mathematical Symbols .................................................................................................................. 37.4 Subscripts ...................................................................................................................................... 37.5 Graphical Symbols for Drawings ................................................................................................ 37.5 Piping System Identification ....................................................................................................... 37.10 HIS chapter contains information about abbreviations and symbols for heating, ventilating, air-conditioning, and refrigerating (HVAC&R) engineers. Abbreviations are shortened forms of names and expressions used in text, drawings, and computer programs. This chapter discusses conventional English-language abbreviations that may be different in other languages. A letter symbol represents a quantity or a unit, not its name, and is independent of language. Because of this, use of a letter symbol is preferred over abbreviations for unit or quantity terms. Letter symbols necessary for individual chapters are defined in the chapters where they occur. Abbreviations are never used for mathematical signs, such as the equality sign (=) or division sign (/), except in computer programming, where the abbreviation functions as a letter symbol. Mathematical operations are performed only with symbols. Abbreviations should be used only where necessary to save time and space; avoid their usage in documents circulated in foreign countries. Graphical symbols in this chapter of piping, ductwork, fittings, and in-line accessories can be used on scale drawings and diagrams. Identifying piping by legend and color promotes greater safety and lessens the chance of error in emergencies. Piping identification is now required throughout the United States by the Occupational Safety and Health Administration (OSHA) for some industries and by many federal, state, and local codes. T Some symbols have two or more options listed. The longest abbreviation is preferred and should be used if possible. However, it is sometimes necessary to shorten the symbol to further identify the variable. For instance, the area of a wall cannot be defined as WALLAREA because some computer languages restrict the number of letters in a variable name. Therefore, a shorter variable symbol is applied, and WALLAREA becomes WALLA or WAREA. Many advanced computer programming languages such as Basic, C, and C++ do not have the limitations of older computer language compilers. It is good programming practice to include the complete name of each variable and to define any abbreviations in the comments section at the beginning of each module of code. Abbreviations should be used to help clarify the variables in an equation and not to obscure the readability of the code. In Table 1, the same symbol is sometimes used for different terms. This liberty is taken because it is unlikely that the two terms would be used in the same program. If such were the case, one of the terms would require a suffix or prefix to differentiate it from the other. LETTER SYMBOLS
Letter symbols include symbols for physical quantities (quantity symbols) and symbols for the units in which these quantities are measured (unit symbols). Quantity symbols, such as I for electric current, are listed in this chapter and are printed in italic type. A unit symbol is a letter or group of letters such as ft for foot or a special sign such as ° for degrees and is printed in Roman type. Subscripts and superscripts are governed by the same principles. Letter symbols are restricted mainly to the English and Greek alphabets. Quantity symbols may be used in mathematical expressions in any way consistent with good mathematical usage. The product of two quantities, a and b, is indicated by ab. The quotient is a/b, or ab 1. To avoid misinterpretation, parentheses must be used if more than one slash (/) is used in an algebraic term; for example, (a/b)/c or a/(b/c) is correct, but not a/b/c. Subscripts and superscripts, or several of them separated by commas, may be attached to a single basic letter (kernel), but not to other subscripts or superscripts. A symbol that has been modified by a superscript should be enclosed in parentheses before an exponent is added (Xa)3. Symbols can also have alphanumeric marks such as (prime), + (plus), and * (asterisk). More detailed information on the general principles of letter symbol standardization are in standards listed at the end of this chapter. The letter symbols, in general, follow these standards, which are out of print: Y10.3M Y10.4-82 Letter Symbols for Mechanics and Time-Related Phenomena Letter Symbols for Heat and Thermodynamics ABBREVIATIONS FOR TEXT, DRAWINGS, AND COMPUTER PROGRAMS
Table 1 gives some abbreviations, as well as others commonly found on mechanical drawings and abbreviations (symbols) used in computer programming. Abbreviations specific to a single subject are defined in the chapters in which they appear. Additional abbreviations used on drawings can be found in the section on Graphical Symbols for Drawings. Computer Programs
The abbreviations (symbols) used for computer programming for the HVAC&R industries have been developed by ASHRAE Technical Committee 1.5, Computer Applications. These symbols identify computer variables, subprograms, subroutines, and functions commonly applied in the industry. Using these symbols enhances comprehension of the program listings and provides a clearly defined nomenclature in applicable computer programs. Certain programming languages differentiate between real numbers (numbers with decimals) and integers (numbers without decimals) by reserving certain initial letters of a variable for integer numbers. Many of the symbols listed in this chapter begin with these letters and, in order to make them real numbers, must be prefixed with a noninteger letter.
The preparation of this chapter is assigned to TC 1.6, Terminology. Other symbols chosen by an author for a physical magnitude not appearing in any standard list should be ones that do not already have different meanings in the field of the text. 37.1 37.2
Table 1 Abbreviations for Text, Drawings, and Computer Programs
Term above finished floor absolute accumulat(e, -or) air condition(-ing, -ed) air-conditioning unit(s) air-handling unit air horsepower alteration alternating current altitude ambient American National Standards Institute1 American wire gage ampere (amp, amps) angle angle of incidence apparatus dew point approximate area atmosphere average azimuth azimuth, solar azimuth, wall barometer(-tric) bill of material boiling point brake horsepower Brown & Sharpe wire gage British thermal unit Celsius center to center circuit clockwise coefficient coefficient, valve flow coil compressor condens(-er, -ing, -ation) conductance conductivity conductors, number of (3) contact factor cooling load counterclockwise cubic feet cubic inch cubic feet per minute cfm, standard conditions cubic ft per sec, standard decibel degree density depth or deep dew-point temperature diameter diameter, inside diameter, outside difference or delta diffuse radiation direct current direct radiation dry dry-bulb temperature effectiveness effective temperature2 efficiency efficiency, fin efficiency, surface Text — abs acc — — — ahp altrn ac alt amb ANSI AWG amp — — adp approx. — atm avg az — — baro b/m bp bhp B&S Btu °C c to c ckt cw coeff. Cv — cprsr cond — cndct 3/c — clg load ccw ft3 in3 cfm scfm scfs dB deg. or ° dens dp dpt dia. ID OD diff., — dc dir radn — dbt — ET* eff — — Drawings AFF ABS ACCUM AIR COND ACU AHU AHP ALTRN AC ALT AMB ANSI AWG AMP — — ADP APPROX — ATM AVG AZ — — BARO BOM BP BHP B&S BTU °C C TO C CKT CW COEF Cv — CMPR COND — CNDCT 3/c — CLG LOAD CCW CU FT CU IN CFM SCFM SCFS DB DEG or ° DENS DP DPT DIA ID OD DIFF DC DIR RADN DBT ET* EFF Program — ABS ACCUM — ACU AHU AHP — AC ALT AMB — — AMP, AMPS ANG ANGI ADP — A — AVG AZ SAZ WAZ — — BP BHP — BTU °C — CKT — COEF CV COIL CMPR COND C K — CF CLOAD — CUFT, CFT CUIN, CIN CFM SCFM SCFS DB DEG RHO DPTH DPT DIA ID OD D, DELTA DFRAD DC DIRAD DRY DB, DBT EFT ET EFF FEFF SEFF Term 2009 ASHRAE Handbook—Fundamentals
Text emf elev. entr EWT EAT — — edr eqiv ft eqiv in evap exp fa f to f fvel — — °F — fpm fps — — — — — ft ft lb fp Hz ga gal gph gpm gpd gr G GTD hd — — HG LHG SHG — — U hgt hps hthw hp h rh W in. — ihp IPS ips kW kWh LH LMTD LTD lat lwt lg lin ft liq LSHVAC ln log Drawings EMF EL ENT EWT EAT — — EDR EQIV FT EQIV IN EVAP EXP FA F to F FVEL — — °F — FPM FPS — — — — — FT FT LB FP HZ GA GAL GPH GPM GPD GR G GTD HD — — HG LHG SHG — — U HGT HPS HTHW HP HR RH W in. — IHP IPS IPS kW KWH LH LMTD LTD LAT LWT LG LF LIQ LSHVAC LN LOG Program — ELEV ENT EWT EAT H S — EQFT EQIN EVAP XPAN FA — FV CFAC, CFACT FFACT, FF F FAN FPM FPS FI, HI FO, HO QAR, QAIR QFL QGA, QGAS FT — FP — GA, GAGE GAL GPH GPM GPD GR G GTD HD HT HTR HG, HEATG HGL HGS HL, HEATL Q U HGT, HT HPS HTHW HP HR RH W IN INANG — — — KW KWH LH, LHEAT LMTD LTD LAT LWT LG, L LF LIQ LSHVAC LN LOG electromotive force elevation entering entering water temperature entering air temperature enthalpy entropy equivalent direct radiation equivalent feet equivalent inches evaporat(-e, -ing, -ed, -or) expansion face area face to face face velocity factor, correction factor, friction Fahrenheit fan feet per minute feet per second film coefficient,3 inside film coefficient,3 outside flow rate, air flow rate, fluid flow rate, gas foot or feet foot-pound freezing point frequency gage or gauge gallons gallons per hour gallons per minute gallons per day grains gravitational constant greatest temp difference head heat heater heat gain heat gain, latent heat gain, sensible heat loss heat transfer heat transfer coefficient height high-pressure steam high-temperature hot water horsepower hour(s) humidity, relative humidity ratio inch incident angle indicated horsepower International Pipe Std iron pipe size kilowatt kilowatt hour latent heat least mean temp. difference4 least temp. difference4 leaving air temperature leaving water temperature length linear feet liquid load-sharing (hybrid) HVAC system logarithm (natural) logarithm to base 10 Abbreviations and Symbols
Term low-pressure steam low-temp. hot water Mach number mass flow rate maximum mean effective temp. mean temp. difference medium-pressure steam medium-temp. hot water mercury miles per hour minimum minute noise criteria normally open normally closed not applicable not in contract not to scale number number of circuits number of tubes ounce outside air parts per million percent phase (electrical) pipe pounds pounds per square foot psf absolute psf gage pounds per square inch psi absolute psi gage pressure pressure, barometric pressure, critical pressure, dynamic (velocity) pressure drop or difference pressure, static pressure, vapor primary quart radian radiat(-e, -or) radiant panel radiation radius Rankine receiver recirculate refrigerant (12, 22, etc.) relative humidity resist(-ance, -ivity, -or) return air revolutions revolutions per minute revolutions per second roughness safety factor saturation Saybolt seconds Furol Saybolt seconds Universal sea level second sensible heat sensible heat gain sensible heat ratio shading coefficient shaft horsepower solar Text lps lthw Mach mfr max. MET MTD mps mthw Hg mph min. min NC no nc na nic — no. — — oz oa ppm % ph — lb psf psfa psfg psi psia psig — baro pr — vp PD sp vap pr pri qt — — RP — — °R rcvr recirc. R-12, R-22 rh res ra rev rpm rps rgh sf sat. ssf ssu sl s SH SHG SHR — sft hp — Drawings LPS LTHW MACH MFR MAX MET MTD MPS MTHW HG MPH MIN MIN NC NO NC N/A NIC NTS NO — — OZ OA PPM % PH — LBS PSF PSFA PSFG PSI PSIA PSIG PRESS BARO PR — VP PD SP VAP PR PRI QT — RAD RP RADN — °R RCVR RECIRC R12, R22 RH RES RA REV RPM RPS RGH SF SAT SSF SSU SL s SH SHG SHR — SFT HP — Program LPS LTHW — MFR MAX MET MTD MPS MTHW HG MPH MIN MIN — — — — — — N, NO NC NT OZ OA PPM PCT — PIPE LBS PSF PSFA PSFG PSI PSIA PSIG PRES, P BP CRIP VP PD, DELTP SP VAP PRIM QT RAD — RP RAD R R REC RCIR, RECIR R12, R22 RH RES, OHMS RA REV RPM RPS RGH, E SF SAT SSF SSU SE SEC SH SHG SHR SC SHP SOL Term specification specific gravity specific heat sp ht at constant pressure sp ht at constant volume specific volume square standard standard time meridian static pressure suction summ(-er, -ary, -ation) supply supply air surface surface, dry surface, wet system tabulat(-e, -ion) tee temperature temperature difference temperature entering temperature leaving thermal conductivity thermal expansion coeff. thermal resistance thermocouple thermostat thick(-ness) thousand circular mils thousand cubic feet thousand foot-pounds thousand pounds time ton tons of refrigeration total total heat transmissivity U-factor unit vacuum valve vapor proof variable variable air volume velocity velocity, wind ventilation, vent vertical viscosity volt volt ampere volume volumetric flow rate wall water watt watt-hour weight wet bulb wet-bulb temperature width wind wind direction wind pressure yard year zone
1Abbreviations 3These 37.3
Text spec SG sp ht cp cv sp vol sq. std — SP suct. — sply sa — — — — tab — temp. TD, t TE TL k — R tc T STAT thkns Mcm Mcf kip ft kip — — tons — tot ht — — — vac v vap prf var VAV vel. w vel. vent vert. visc V VA vol. — — — W Wh wt wb wbt — — wdir wpr yd yr z Drawings SPEC SG SP HT cp cv SP VOL SQ STD — SP SUCT — SPLY SA — — — — TAB — TEMP TD TE TL K — R TC T STAT THKNS MCM MCF KIP FT KIP T — TONS — TOT HT — — — VAC V VAP PRF VAR VAV VEL W VEL VENT VERT VISC V VA VOL — — — W WH WT WB WBT — — WDIR WPR YD YR Z Program — — C CP CV V, CVOL SQ STD STM SP SUCT, SUC SUM SUP, SPLY SA SUR, S SURD SURW SYS TAB TEE T, TEMP TD, TDIF TE, TENT TL, TLEA K TXPC RES, R TC, TCPL T STAT THK MCM MCF KIPFT KIP T TON TONS TOT — TAU U UNIT VAC VLV — VAR VAV VEL, V W VEL VENT VERT MU, VISC E, VOLTS VA VOL VFR W, WAL WTR WAT, W WHR WT WB WBT WI WD WDIR WP, WPRES YD YR Z, ZN of most proper names use capital letters in both text and drawings. 9 of this volume. are surface heat transfer coefficients. 4Letter L also used for Logarithm of these temperature differences in computer programming.
2The asterisk (*) is used with ET*, effective temperature, as in Chapter 37.4
Symbol a A b B c c cp cv C C C CL CP d d or D De or Dh Dv e E E f f fD Description of Item Typical Units fps or fpm ft2 ft psia or in. Hg lb/ft3, mol/ft3 Btu/lb °F Btu/lb °F Btu/lb °F — Btu/h °F Btu/h ft2 °F — — — ft ft ft2/s — Btu V Btu/h ft2 °F Hz — — lbf — ft/s2 lb/h ft2 Btu/h ft2 °F ft Btu/lb Btu/lb lb/h ft2 lb per ft3 Btu/lb Btu A ft lbf /Btu Btu/h ft °F — — lb/h ft2 ft dB dB lb lb/lb mol — rpm psi psi psi psi hp, watts Btu/h Btu cfm ft ft2 h °F/Btu ft lbf /lbm °R Btu/lb °R Btu/°R °F °F °R Btu/lb Btu Btu/h ft2 °F ft3/lb acoustic velocity area breadth or width barometric pressure concentration specific heat specific heat at constant pressure specific heat at constant volume coefficient fluid capacity rate thermal conductance loss coefficient coefficient of performance prefix meaning differential diameter equivalent or hydraulic diameter mass diffusivity base of natural logarithms energy electrical potential film conductance (alternate for h) frequency friction factor, Darcy-Weisbach formulation friction factor, Fanning formulation fF F force Fij angle factor (radiation) g gravitational acceleration G mass velocity h heat transfer coefficient h hydraulic head h specific enthalpy ha enthalpy of dry air hD mass transfer coefficient hs enthalpy of moist air at saturation H total enthalpy I electric current J mechanical equivalent of heat k thermal conductivity k (or ) ratio of specific heats, cp /cv K proportionality constant KD mass transfer coefficient l or L length Lp sound pressure Lw sound power m or M mass M molecular weight n or N number in general N rate of rotation p or P pressure pa partial pressure of dry air ps partial pressure of water vapor in moist air vapor pressure of water in saturated pw moist air P power q time rate of heat transfer Q total heat transfer Q volumetric flow rate r radius r or R thermal resistance R gas constant s specific entropy S total entropy t temperature tm or Tm mean temperature difference T absolute temperature u specific internal energy U total internal energy U overall heat transfer coefficient v specific volume Symbol V V w W W W Ws x x x,y,z Z 2009 ASHRAE Handbook—Fundamentals
Description of Item total volume linear velocity mass rate of flow weight humidity ratio of moist air work humidity ratio of moist air at saturation mole fraction quality, mass fraction of vapor lengths along principal coordinate axes figure of merit absolute Seebeck coefficient absorptivity, absorptance radiation linear coefficient of thermal expansion thermal diffusivity volume coefficient of thermal expansion ratio of specific heats, cp /cv specific weight difference between values emissivity, emittance (radiation) time efficiency or effectiveness wavelength degree of saturation dynamic viscosity kinematic viscosity density reflectivity, reflectance (radiation) volume resistivity Stefan-Boltzmann constant surface tension stress time transmissivity, transmittance (radiation) relative humidity Typical Units ft3 fps lb/h lbf lb(water)/lb(dry air) ft lbf lb(water)/lb(dry air) — — ft — V/°C — per °F ft2/h per °F — lbf /ft3 — — s, h — nm — lb/ft h ft2/h lb/ft3 — cm Btu/h ft2 °R4 lbf /ft lbf /ft2 s, h — — (or k) DIMENSIONLESS NUMBERS
Fo Gr Gz jD jH Le M Nu Pe Pr Re Sc Sh St Str Fourier number Grashof number Graetz number Colburn mass transfer Colburn heat transfer Lewis number Mach number Nusselt number Peclet number Prandtl number Reynolds number Schmidt number Sherwood number Stanton number Strouhal number /L2 L3 2 g( t)/ wcp /kL Sh/ReSc1/3 Nu/RePr1/3 /Dv V/a hD/k GDcp /k cp /k VD/ Dv hD L/Dv h/Gcp fd/V
2 MATHEMATICAL SYMBOLS
equal to not equal to approximately equal to greater than less than greater than or equal to less than or equal to plus minus plus or minus a multiplied by b a divided by b ratio of circumference of a circle to its diameter = < + ± ab, a b, a b a -- , a/b, ab–1 b Abbreviations and Symbols
a raised to the power n square root of a infinity percent summation of natural log logarithm to base 10 an a,a % ln log
Low-pressure steam condensate Boiler blowdown Pumped condensate Vacuum pump discharge Makeup water Atmospheric vent Fuel oil Low-temperature hot water supply Medium-temperature hot water supply High-temperature hot water supply Low-temperature hot water return Medium-temperature hot water return High-temperature hot water return Compressed air Vacuum (air) Existing piping Pipe to be removed Air Conditioning and Refrigeration Refrigerant discharge Refrigerant suction Brine supply Brine return Condenser water supply Condenser water return Chilled water supply Chilled water return Fill line Humidification line Drain Hot/chilled water supply Hot/chilled water return Refrigerant liquid Heat pump water supply Heat pump water return Plumbing Sanitary drain above floor or grade Sanitary drain below floor or grade Storm drain above floor or grade Storm drain below floor or grade Condensate drain above floor or grade Condensate drain below floor or grade Vent Cold water Hot water Hot water return Gas Acid waste Drinking water supply Chemical supply pipesa Floor drain Funnel drain, open
LPC BBD PC VPD MU ATV FO(NAME) HWS MTWS HTWS HWR MTWR HTWR A(NAME) VAC (NAME)E XX (NAME) XX RD RS B BR CWS CWR CHWS CHWR FILL H D H/C S H/C R RL HPWS HPWR SAN SAN ST ST CD CD ––––––––––– SUBSCRIPTS These are to be affixed to the appropriate symbols. Several subscripts may be used together to denote combinations of various states, points, or paths. Often the subscript indicates that a particular property is to be kept constant in a process.
a,b,... referring to different phases, states or physical conditions of a substance, or to different substances a air a ambient b barometric (pressure) c referring to critical state or critical value c convection db dry bulb dp dew point e base of natural logarithms f referring to saturated liquid f film fg referring to evaporation or condensation F friction g referring to saturated vapor h referring to change of phase in evaporation H water vapor i referring to saturated solid i internal if referring to change of phase in melting ig referring to change of phase in sublimation k kinetic L latent m mean value M molar basis p referring to constant pressure conditions or processes p potential r refrigerant r radiant or radiation s referring to moist air at saturation s sensible s referring to isentropic conditions or processes s static (pressure) s surface t total (pressure) T referring to isothermal conditions or processes v referring to constant volume conditions or processes v vapor v velocity (pressure) w wall w water wb wet bulb 0 referring to initial or standard states or conditions 1,2,... different points in a process, or different instants of time G AW DCW (NAME) G Fire Safety Devicesb
Signal Initiating Detectors Heat (thermal) Smoke Gas Flame GRAPHICAL SYMBOLS FOR DRAWINGS Graphical symbols have been extracted from ANSI/ASHRAE Standard 134-2005. Additional symbols are from current practice and extracted from ASME Standards Y32.2.3 and Y32.2.4.
Piping Heating High-pressure steam Medium-pressure steam Low-pressure steam High-pressure steam condensate Medium-pressure steam condensate
HPS MPS LPS HPC MPC Radiant Panels a See b Refer section on Piping Identification in this chapter. to Standard for Fire Safety Symbols, 1999 edition (NFPA Standard 170). 37.6
Radiant Ceiling Panels Embedded Above ceiling Surface mounted Suspended Radiant Floor Panels Slab on grade Above subfloor Below subfloor Slab above subfloor Radiant Wall Panels 2009 ASHRAE Handbook—Fundamentals
Valves Actuators Manual Non-rising sun Outside stem & yoke Lever Gear Electric Motor Solenoid Pneumatic Motor Diaphragm Valves, Special Duty Check, swing gate Check, spring Control, electric-pneumatic Control, pneumatic-electric Hose end drain Embedded Surface mounted Decorative Lock shield Needle Pressure-reducing regulator Quick-opening Coils
Cooling coil Heating coil Quick-closing Safety or relief Electrical coil Solenoid Square-head cock Humidifier Unclassified (number and specify) Fittings Valves
Valves for Selective Actuators Air line Ball Flanged Butterfly Diaphragm Gate Gate, angle Globe Globe, angle Plug valve Elbow, facing toward viewer Three way
a Includes The following fittings are shown without connection notations. This reflects current practice. The symbol for the body of a fitting is the same for all types of connections, unless otherwise specified. The types of connections are often specified for a range of pipe sizes, but are shown with the fitting symbol where required. For example, an elbow would be: Threaded Belt & Spigot Weldeda Fitting Bushing Cap Cross Elbow, 90° Elbow, 45° Soldered Solvent Cement Symbol fusion; specify type. Abbreviations and Symbols
Elbow, facing away from viewer Elbow, base-supported Lateral Reducer, concentric Reducer, eccentric, flat on bottom Reducer, eccentric, flat on top Tee Tee, facing toward viewer Tee, facing away from viewer Union, screwed Union, flanged Propeller Roof ventilator, intake Roof ventilator, exhaust Roof ventilator, louvered Vaneaxial Air separator Pipe guide Anchor, intermediate Anchor, main Ball joint Expansion joint Expansion loop Flexible connector Flowmeter, orifice plate with flanges Flowmeter, venturi Flow switch Hanger rod Hanger spring Heat exchanger, liquid Heat transfer surface (indicate type) Pitch of pipe, rise (R) drop (D) Pressure gage and cock Pressure switch Pump (indicate use) Pump suction diffuser Spool piece, flanged Strainer Terminal unit, variable volume Strainer, blow off Strainer, duplex Tank (indicate use) Sound attenuator Terminal unit, mixing Duct section, return Duct size, where first dimension is visible duct Duct section, supply Ductworka,b Direction of flow Thermometer well, only Thermostat Traps, steam (indicate type) Unit heater (indicate type) Thermometer 37.7 Air-Moving Devices and Components
Fans (indicate use) Centrifugal Piping Specialties
Air vent, automatic Air vent, manual Duct section, exhaust Change of elevation rise (R) drop (D) Access doors, vertical or horizontal Cowl, (gooseneck) and flashing Duct lining Flexible connection Flexible duct a Units of measurement are not shown here, but should be shown on drawings. The first dimension is visible duct dimension for duct size, top dimension for grilles, and horizontal dimension for registers. bShow volumetric flow rate at each device. 37.8
Transitiona Turning vanes 2009 ASHRAE Handbook—Fundamentals
Reciprocating Rotary Rotary screw Smoke detectors Dampers Backdraft damper Condensers Air cooled Evaporative Fire damper Water cooled, (specify type) Manual volume Condensing Units Air cooleda Smoke damper Water cooleda Grilles, Register and Diffusersb Sidewall inlet, (exhaust) outlet, registers, and grilles Sidewall outlet, registers, and grilles Rectangular four-way outlet, supply Condenser-Evaporator (Cascade System) Cooling Towers Cooling tower Spray pond Louver and screen Evaporatorsb Finned coil Transfer grille or louver Forced convection Door grille or louver Immersion cooling unit Plate coil Pipe coilc Ceiling diffuser, rectangular Liquid Chillers (Chillers only) Direct expansiond Round outlet Floodedd Linear outlet Tank, closed Light troffer outlet Tank, open Chilling Units Undercut door Refrigeration
aIndicate bShow Absorption aL flat on bottom or top (FOB or FOT), if applicable. volumetric flow rate at each device. = Liquid being cooled, RL = Refrigerant liquid, RS = Refrigerant suction. manifolding. used diagrammatically as evaporator and/or condenser with label indicating name and type. d L = Liquid being cooled, RL = Refrigerant liquid, RS = Refrigerant suction.
bSpecify c Frequently Abbreviations and Symbols
Valve, condenser water regulating 37.9 Centrifugal Auxiliary Equipment
Reciprocating Refrigerant Filter Rotary screw Controls
Refrigerant Controls Capillary tube Expansion valve, hand Expansion valve, automatic Strainer Filter and drier Scale trap Drier Vibration absorber Expansion valve, thermostatic Heat exchanger Float valve, high side, or liquid drain valve Float valve, low side Thermal bulb Solenoid valve Oil separator Sight glass Fusible plug Rupture disk Receiver, high-pressure, horizontal Receiver, high-pressure, vertical Constant pressure valve, suction Evaporator pressure regulating valve, thermostatic, throttling Evaporator pressure regulating valve, thermostatic, snap-action Evaporator pressure regulating valve, throttling-type, evaporator side Compressor suction valve, pressure-limiting, throttlingtype, compressor side Thermosuction valve Receiver, low-pressure Intercooler Intercooler/desuperheater Snap-action valve Energy Recovery Equipment
Refrigerant reversing valve Temperature or Temperature-Actuated Electrical or Flow Controls Thermostat, self-contained Thermostat, remote bulb Coil loop Sensor, temperature Heat pipe Pressure-reducing regulator Pressure regulator Fixed plate Condenser, double bundle Air to Air Energy Recovery Rotary heat wheel 37.10 2009 ASHRAE Handbook—Fundamentals
Table 2 Examples of Legends Plate fin, crossflow Power Sources
Motor, electric (number for identification of description in specifications) Engine (indicate fuel) Classification Gas turbine Steam turbine Steam turbine, condensing HOT WATER AIR 100 PSIG H.P. RETURN STEAM 100 PSIG Table 3 Classification of Hazardous Materials and Designation of Colorsa
Color Field Colors of Letters for Legend Black Black Black Yellow Black White White Electrical Equipmenta Symbols for electrical equipment shown on mechanical drawings are usually geometric figures with an appropriate name or abbreviation, with details described in the specifications. The following are some common examples.b Motor control Disconnect switch, unfused Disconnect switch, fused Time clock Automatic filter panel Lighting panel Power panel
a See b Number Materials Inherently Hazardous Flammable or explosive Yellow Chemically active or toxic Yellow Extreme temperatures or pressures Yellow Radioactiveb Purple Materials of Inherently Low Hazard Liquid or liquid admixturec Green Gas or gaseous admixture Blue Fire Quenching Materials Water, foam, CO2, Halon, etc. Red
a When preceding color scheme is used, colors b Previously should be as recommended in latest revi- sion of NEMA Standard Z535.1. specified radioactive markers using yellow or purple are acceptable if already installed and/or until existing supplies are depleted, subject to applicable federal regulations. cMarkers with black letters on green field are acceptable if already installed and/or until existing supplies are depleted. Fig. 1 Visibility of Pipe Markings ARI Standard 130 for preferred symbols of common electrical parts. each symbol if more than one; see ASME Standard Y32.4. PIPING SYSTEM IDENTIFICATION
The material in piping systems is identified to promote greater safety and lessen the chances of error, confusion, or inaction in times of emergency. Primary identification should be by means of a lettered legend naming the material conveyed by the piping. In addition to, but not instead of lettered identification, color can be used to identify the hazards or use of the material. The data in this section have been extracted from ASME Standard A13.1. Fig. 1 Visibility of Pipe Markings Fire Quenching Materials. This classification includes sprinkler systems and other piped fire fighting or fire protection equipment. This includes water (for fire fighting), chemical foam, CO2, Halon, and so forth. Definitions
Piping Systems. Piping systems include pipes of any kind, fittings, valves, and pipe coverings. Supports, brackets, and other accessories are not included. Pipes are defined as conduits for the transport of gases, liquids, semiliquids, or fine particulate dust. Materials Inherently Hazardous to Life and Property. There are four categories of hazardous materials: • Flammable or explosive materials that are easily ignited, including materials known as fire producers or explosives • Chemically active or toxic materials that are corrosive or are in themselves toxic or productive of poisonous gases • Materials at extreme temperatures or pressures that, when released from the piping, cause a sudden outburst with the potential for inflicting injury or property damage by burns, impingement, or flashing to vapor state • Radioactive materials that emit ionizing radiation Materials of Inherently Low Hazard. All materials that are not hazardous by nature, and are near enough to ambient pressure and temperature that people working on systems carrying these materials run little risk through their release. Method of Identification
Legend. The legend is the primary and explicit identification of content. Positive identification of the content of the piping system is by lettered legend giving the name of the contents, in full or abbreviated form, as shown in Table 2. Arrows should be used to indicate the direction of flow. Use the legend to identify contents exactly and to provide temperature, pressure, and other details necessary to identify the hazard. The legend shall be brief, informative, pointed, and simple. Legends should be applied close to valves and adjacent to changes in direction, branches, and where pipes pass through walls or floors, and as frequently as needed along straight runs to provide clear and positive identification. Identification may be applied by stenciling, tape, or markers (see Figure 1). The number and location of identification markers on a particular piping system is based on judgment. Color. Colors listed in Table 3 are used to identify the characteristic properties of the contents. Color can be shown on or contiguous to the piping by any physical means, but it should be used Abbreviations and Symbols
Table 4 Size of Legend Letters
Outside Diameter of Pipe or Covering, in. 3/4 to 1 1/4 1 1/2 to 2 2 1/2 to 6 8 to 10 over 10 Length of Color Field A, in. 8 8 12 24 32 Size of Letters B, in. 1/2 3/4 1-1/4 2-1/2 3-1/2 37.11
CODES AND STANDARDS
ARI. 1988. Graphic electrical/electronic symbols for air-conditioning and refrigeration equipment. Standard 130-88. ASHRAE. 2005. Graphic symbols for heating, ventilating, air-conditioning, and refrigeration systems. ANSI/ASHRAE Standard 134-2005. ASME. 2007. Standard markers for pipe identification. ANSI/ASME Standard A13.1-2007. American Society of Mechanical Engineers, New York. ASME. 1988. Letter symbols: Glossary of terms concerning letter symbols. Standard Y10.1-1972 (R1988). American Society of Mechanical Engineers, New York. ASME. 1984. Letter symbols and abbreviations for quantities used in acoustics. Standard Y10.11-1984. American Society of Mechanical Engineers, New York. ASME. 1987. Illuminating engineering. Standard Y10.18-1967 (R1977). American Society of Mechanical Engineers, New York. ASME. 1999. Graphical symbols for pipe fittings, valves, and piping. Standard Y32.2.3. American Society of Mechanical Engineers, New York. ASME. 1998. Graphical symbols for heating, ventilating, and air conditioning. Standard Y32.2.4. American Society of Mechanical Engineers, New York. IEEE. 2004. Standard letter symbols for units of measurement. Standard 260.1-2004. Institute of Electrical and Electronics Engineers, Piscataway, NJ. IEEE. 1996. Letter symbols and abbreviations used in acoustics. Standard 260.4-1996. Institute of Electrical and Electronics Engineers, Piscataway, NJ. NEMA. 2002. Safety color code. Standard Z535-2002. National Electrical Manufacturers Association, Rosslyn, VA. NFPA. 2006. Standard for fire safety and emergency symbols, 2006 edition. Standard 170. National Fire Protection Association, Quincy, MA. in combination with a legend. Color can be used in continuous total length coverage or in intermittent displays. Visibility. Pipe markings should be highly visible. If pipe lines are above the normal line of vision, the lettering is placed below the horizontal centerline of the pipe (Figure 1). Type and Size of Letters. Provide the maximum contrast between color field and legend (Table 3). Table 4 shows the size of letters recommended. Use of standard size letters of 1/2 in. or larger is recommended. For identifying materials in pipes of less than 3/4 in. in diameter and for valve and fitting identification, use a permanently legible tag. Unusual or Extreme Situations. When the piping layout occurs in or creates an area of limited accessibility or is extremely complex, other identification techniques may be required. While a certain amount of imagination may be needed, the designer should always clearly identify the hazard and use the recommended color and legend guidelines. ...
View Full Document
This note was uploaded on 03/08/2011 for the course ASME 293 taught by Professor Range during the Spring '11 term at Prairie View A & M.
- Spring '11