Premium Performance Direct Spring Valves Series 60 and 80 - Sizing ANDERSON GREENWOOD. Note. How to Size a Valve

Transcription

1 ANDERSON GREENWOOD Preliminary Selection Guide Applications Body Material Valve Gas/ Gas/Liquid Seat Set Relieving Balanced Type Vapor Liquid Thermal Steam Type Brass CS SS Pressure Temperature for Back Relief barg [psig] C [ F] Pressure 81 X X Plastic X X X [50-10,000] -253 C C [-423 F F] N 81P X X Plastic X X X [50-6,000] -40 C C [-40 F F] Y 83 X X O-ring X X X [20-2,000 ] -40 C C [-40 F F] N 86 X Plastic X X X [ ] -253 C C [-423 F F] N 61 X X Plastic X [ ] -196 C C [-320 F F] N 63B X X O-ring X [ ] -40 C C [-40 F F] N 1. Minimum and maximum set pressures may not be available in all orifice sizes (see AGCDS-0032 pages 1-4). How to Size a Valve Pressure relief valves are selected on the basis of their ability to meet an expected relieving condition and flowing a sufficient amount of fluid to prevent excessive pressure increase. This means that the size of the valve orifices must be calculated taking the required flow, lading fluid properties, and other factors into consideration. To select the minimum required orifice area that will flow the required capacity of the system you wish to protect, please refer to the following information, which appears in this section: 1. Sizing formulas 2. Physical properties of the fluid to be relieved 3. Capacities of different orifice areas at different pressures 4. Conversion tables to aid calculations Once you have determined the required orifice area for your service conditions, refer to Ordering, pages 18 through 44, to select a specific valve model number. Orifice Areas and Nozzle Coefficient The orifice areas and nozzle coefficients for all Series 80 valves are tabulated in the table below. These values are derived from the values certified by the National Board of Boiler and Pressure Vessel Inspectors, in accordance with Section VIII, Divisionž1 of the ASME Pressure Vessel Code. Verification of Sizing Orifice area calculations are made and/or verified whenever sufficient data is provided. If no data is furnished, the size selection responsibility will remain totally with the purchaser. Nozzle Coefficient and Available Orifice Sizes, cm# [in#] Valve K Type [0.049] [0.077] [0.110] [0.150] [0.196] [0.307] [0.503] [0.785] [1.287] (-4) (-5) (-6) (-7) (-8 or E) (F) (G) (H) (J) X X X X X X X 81P X X X X X X X X X X X X X X X X X Emerson.com/FinalControl 2017 Emerson. All rights reserved. without notice AGCDR-0031-EN-1308

2 Vapors or Gases (capacity in scfm) 1 V MTZ A = 6.32 CKP1 Steam (capacity in lb/hr ) 1 W A = 51.5 K P1 K s Vapors or Gases (capacity in lb/hr ) 1 W TZ A = CKP 1 M Liquids (capacity in gpm) A = V L G 38 K K P K W K V P A P B English Sizing Formulas Orifice area calculations are made and/or verified whenever sufficient data is provided. If no data is furnished, the size selection responsibility will remain totally with the purchaser. V = Required capacity, SCFM W = Required capacity, lb/hr VL = Required capacity, gpm G = Specific gravity of liquid at flowing temperature referred to water = 1.00 at 70 F (see Physical Properties on pages 12-14) W C K P 1 P A = Required capacity, lb/hr = Gas constant based on k (if unknown, assume C = 315; see Physical Properties on pages 10-11; also see page 8) = Nozzle coefficient for 90 percent of actual capacity, derived from National Board Certified Testing (see page 4) = Inlet flowing pressure, psia = Set pressure - inlet pressure loss + allowable overpressure = Inlet flowing pressure, psig = Set pressure - inlet pressure loss + allowable overpressure M = Molecular weight of vapor or gas (M = 29 x G, see Physical Properties on pages 10-11) PB = Back pressure - psig K p = Overpressure correction factor, 1.0 T = Relief temperature, R ( R = F + 460) K w = Back pressure correction factor (see page 7) Z = Compressibility factor (if unknown, assume Z = 1.0) k = Specific heat ratio k = C p C V K v = Viscosity correction factor (see page 7) K s = Superheat correction factor (for saturated steam, K s = 1.0, refer to Table on page 9) 1. As is accepted industry practice, built-up back pressure for conventional (unbalanced) gas or steam valves should not exceed 10 percent. Emerson reserves the right to change the contents without notice page 2

3 Vapors or Gases (capacity in Nm 3 /hr ) 1 V MTZ A = CKP 1 Vapors or Gases (capacity in kg/hr ) W TZ A = CKP 1 M Steam (capacity in kg/hr ) 1 W A = 52.5 K P 1 K s Liquids (capacity in M 3 /hr ) V L G A = K K P K W K V P A P B Metric Sizing Formulas A = Calculated orifice area, cm 2 V = Required capacity, Nm 3 /hr W = Required capacity, kg/hr V L = Required capacity, M 3 /hr G = Specific gravity (Relative Density) of liquid at flowing temperature referred to water = 1.00 at 20 C (see Physical Properties on pages 12-14) M = Molecular weight of vapor or gas (M = 29 x G, see Physical Properties on pages 10-11) T = Relief temperature, K ( K = C + 273) Z = Compressibility factor (if unknown, assume Z = 1.0) C K = Gas constant based on k (if unknown, assume C = 315; see Physical Properties on pages 10-14; also see page 8) = Nozzle coefficient for 90 percent of actual capacity, derived from National Board Certified Testing (see page 4) P 1 = Inlet flowing pressure, bara = Set pressure - inlet pressure loss + allowable overpressure bars P A = Inlet flowing pressure, psig = Set pressure - inlet pressure loss + allowable overpressure P B = Back pressure, barg K p = Overpressure correction factor, 1.0 K w = Back pressure correction factor (see page 7) K v = Viscosity correction factor (see page 7) k = Specific heat ratio k = C p C V K s = Superheat correction factor (for saturated steam, K s = 1.0, refer to Table on page 9) 1. As is accepted industry practice, built-up back pressure for conventional (unbalanced) gas or steam valves should not exceed 10 percent. Emerson reserves the right to change the contents without notice page 3

4 Determining K v and K w K w = Back Pressure Correction Factor Based on 10% Overpressure K V = Viscosity Correction Factor ,000 2,000 10,000 20, ,000 Correction Curve for Types 81P - G and 81P - J R = Reynolds Number Correction Curve for Types 81P - 4 and 81P Percentage Back Pressure = Back Pressure, barg [psig] Set Pressure, barg [psig] English Units V L (2,800 G) R = µ A or Determining K v V L = Flow rate at the flowing temperature, in U.S. gpm [m 3 /hr ] G R = 12,700 V L U A Metric Units R = 31,313 V L G µ A = Specific gravity of liquid at flowing temperature referred to water = 1.00 at 21 C [70 F] µ = Absolute viscosity at the flowing temperature, in centipoises A U = Effective discharge area, in square inches [cm 2 ] (from manufacturer s standard orifice areas) = Viscosity at the flowing temperature, in Saybolt Universal seconds After the value of R is determined, the factor K v is obtained from the graph. Factor K v is applied to correct the preliminary required discharge area. If the corrected area exceeds the chosen standard orifice area, the calculations should be repeated using the next larger standard orifice size. Determining K w See graph at right. Emerson reserves the right to change the contents without notice page 4

5 Determining C, based on k Gas Constant, C k C k C Steam Super Heat Correction Factor, K s Set Saturated Total Steam Temperature in, C [ F] Pressure Steam Temp barg [psig] C [ F] [300] [320] [340] [360] [380] [400] [420] [440] [460] [480] [500] [520] [540] [560] 3.5 [50] 148 [298] [60] 153 [308] [80] 162 [324] [100] 170 [338] [120] 177 [350] [140] 183 [361] [160] 188 [371] [180] 193 [380] [200] 198 [388] [220] 202 [395] [240] 206 [403] [260] 210 [409] [280] 213 [416] [300] 217 [422] [350] 225 [436] [400] 231 [448] [450] 238 [460] [500] 243 [470] [550] 249 [480] [600] 254 [489] [650] 258 [497] [700] 263 [506] [750] 267 [513] Emerson reserves the right to change the contents without notice page 5

6 Physical Properties M k C Gas or Vapor Molecular Specific Gas Constant Weight Heat Ratio Acetone Acetylene (Ethyne) Air Ammonia, Anhydrous Argon Benzene (Benzol or Benzole) Boron Trifluoride Butadiene-1,3 (Divinyl) Butane-n (Normal Butane) Butylene (1-Butene) Carbon Dioxide Carbon Disulfide (C. Bisulfide) Carbon Monoxide Carbon Tetrachloride Chlorine Chloromethane (Methyl Chloride) Cyclohexane Cyclopropane (Trimethylene) Decane-n Diethylene Glycol (DEG) Dimethyl Ether (Methyl Ether) Dowtherm A Dowtherm E Ethane Ethyl Alcohol (Ethanol) Ethylene (Ethene) Ethylene Glycol Ethylene Oxide Fluorocarbons: 12, Dichlorodifluoromethane 13, Chlorotrifluoromethane 13B1, Bromotrifluoromethane 22, Chlorodifluoromethane 115, Chloropentafluoroethane Glycerine (Glycerin or Glycerol) Helium Heptane Hexane Hydrogen Hydrogen Chloride, Anhydrous Hydrogen Sulfide Isobutane (2-Methylpropane) Isoprene (2-Methyl-1, 3 Butadiene) Isopropyl Alcohol (Isopropanol) Krypton Methane Methyl Alcohol (Methanol) Methylamines, Anhydrous Monomethylamine (Methylamine) Dimethylamine Trimethylamine Methyl Mercapton (Methanethiol) Napthalene (Napthaline) Natural Gas (specific gravity = 0.60) Neon Nitrogen Nitrous Oxide Octane Oxygen Pentane Propadiene (Allene) Propane Propylene (Propene) Propylene Oxide Styrene Sulfur Dioxide Sulfur Hexafluoride Steam Toluene (Toluol or Methylbenzene) Triethylene Glycol (TEG) Vinyl Chloride Monomer (VCM) Xenon Xylene (p-xylene) Emerson reserves the right to change the contents without notice page 6

7 Physical Properties G Liquid Specific Gravity C [ F] Water = 1 Acetaldehyde Acetic Acid Acetone Ammonia, Anhydrous Automotive Crankcase and Gear Oils: SAE-5W Through SAE 150 Beer Benzene (Benzol) Boron Trifluoride Butadiene - 1, 3 Butane-n (Normal Butane) Butylene (1-Butene) Carbon Dioxide Carbon Disulfide (C. Bisulfide) Carbon Tetrachloride Chlorine Chloromethane (Methyl Chloride) Crude Oils: 32.6 Deg API 35.6 Deg API 40 Deg API 48 Deg API Cyclohexane Cyclopropane (Trimethylene) Decane-n Diesel Fuel Oils Diethylene Glycol (DEG) Dimethyl Ether (Methyl Ether) Dowtherm A Dowtherm E Ethane Ethyl Alcohol (Ethano Ethylene (Ethene) Ethylene Glycol Ethylene Oxide Fluorocarbons: R12, Dichlorodifluoromethane R13, Chlorotrifluoromethane R13B1, Bromotrifluoromethane R22, Chlorodifluoromethane R115, Chloropentafluoromethane Fuel Oils, Nos. 1, 2, 3, 5 and 6 Gasolines Glycerine (Glycerin or Glycerol) Heptane0 Hexane Hydrochloric Acid Hydrogen Sulfide Isobutane (2-Methylpropane) Isoprene (2-Methyl - 1, 3-Butadiene) Isopropyl Alcohol (Isopropanol) Jet Fuel (average) Kerosene Methyl Alcohol (Methanol) Methylamines, Anhydrous: Monomethylamine (Methylamine) Dimethylamine Trimethylamine Methyl Mercapton (Methanethiol) Nitric Acid Nitrous Oxide Octane Pentane Propadiene (Allene) Propane Propylene (Propene) Propylene Oxide Styrene Sulfur Dioxide Sulfur Hexafluoride Sulfuric Acid: % 60% 20% Toluene (Toluol or Methylbenzene) Triethylene Glycol (TEG) Vinyl Chloride Monomer (VCM) Water, fresh Water, sea Xylene (p-xylene) [68] [68] [68] [68] [60] [60] [68] [-148] [68] [68] [68] [-4] [68] [68] [68] [68] [60] [60] [60] [60] [68] [68] [68] [60] [68] [68] [68] [68] [68] [68] [-155] [68] [68] [68] [68] [68] [68] [68] [60] [60] [68] [68] [68] [60] [68] [68] [68] [68] [60] [60] [68] [68] [68] [68] [68] [60] [-127] [68] [68] [-30] [68] [68] [68] [68] [68] [68] [68] [68] [68] [68] [68] [-4] [68] [68] [68] Emerson reserves the right to change the contents without notice page 7

8 Gas Flow Conversions scfm 2 scfh 2 lb/hr 3 or #/hr 3 kg/hr 4 Nm 3 /hr 5 Nm 3 /min 5 scfm scfh lb/hr [kg/hr ] [Nm 3 /hr ] [Nm 3 /min] 60 M M M M M M M M M M M M M M M M 60 If flow is expressed in actual volume, such as cfm (cubic feet per minute) or acfm (actual cfm) as is often done for compressors, where the flow is described as displacement or swept volume, the flow may be converted to scfm as follows (or from flow expressed in m 3 / hr to Nm 3 /hr ). Inch-Pound Units ( acfm ) t cfm p 520 scfm = or x x Where: p = gauge pressure of gas or vapor in psig t = temperature of gas or vapor in F Metric Units p Nm 3 /hr = n 3 hr = x x t Where: p = gauge pressure of gas or vapor in barg t = temperature of gas or vapor in C s 1. M = Molecular weight of vapor or gas. 2. Volumetric flow (per time unit of hour or minute as shown) in standard cubic feet per minute at bara [14.7 psia], 16 C [60 F]. 3. Weight flow in pounds per hour. 4. Weight flow in kilograms per hour. 5. Volumetric flow (per time unit of hour or minute as shown) at bara 0 C [32 F]. This represents the commercial standard, known as the Normal Temperature and Pressure (NTP). Conversions from one volumetric flow rate to another or to weight flow (and vice versa) may only be done when the volumetric flow is expressed in the standard conditions shown above. If flows are expressed at temperature or pressure bases that differ from those listed above, they must first be converted to the standard base. Pressure Conversion kpa (kilopascal) psig (pounds/in 2 ) 3 kg/cm 2(1) (kilograms/cm 2 ) barg Area Conversion in 2 cm 2 ft 2 mm 2 kpa psig kg/cm 2 barg in 2 ft 2 mm 2 cm x x s 1. Also expressed as kp/cm 2 and kgf/cm Normal Temperature and Pressure (NTP) Conditions are, at sea level, equal to bara or kg/cm 2 (kilograms force per square centimeter absolute) at a base temperature of 32 F [0 C]. This differs slightly from Metric Standard Conditions (MSC), which uses bara 60 F [15 C] for the base temperature. 3. Inch-Pound Standard Conditions are, at sea level, equal to 14.7 psia (pounds force per square inch absolute), rounded up from psia, and at a base temperature of 16 C [60 F]. Emerson reserves the right to change the contents without notice page 8

9 s 1. Kinematic viscosity x specific gravity = absolute viscosity. 2. Centistokes x specific gravity = centipoise. 3. Saybolt Second Universal (SSU) x x specific gravity = centipoise. Absolute Viscosity poise centipoise gm cm sec lb ft-sec poise Centipoise gm lb cm sec ft sec Kinematic Viscosity stoke centistoke cm 2 sec ft 2 sec stoke Centistoke cm 2 ft 2 sec sec x G = Specific gravity of liquid at its relieving temperature compared to that of water at 20 C [68 F], where G water = Liquid Flow Conversions l/hr (litres/hour) gpm (US gallons per minute) gpm (Imperial gallons per minute) barrels/day (petroleum - 42 US gallons) m 3 /hr (cubic meters per hour) m 3 /s (cubic meters per seconds) kg/hr (kilograms per hour) lb/hr (pounds per hour) l/hr gpm - US gpm - Imp barrels/day m 3 /hr x G 227.1G 272.8G G 1000G G 500.8G 601.5G 14.61G 2205G Emerson reserves the right to change the contents without notice page 9