Refrigerant Piping Handbook

1 Refrigerant Piping HandbookRefrigerant Piping DenisonAcknowledgementsSuvarefrigerants DedicationThe author wishes to acknowledge the contribution of various friends, co-workers and former colleagues. Gino DiFebo, Nick Reggi, Wesley Taylor and Laurence White enriched the pages of this work with their perspectives and knowledge. Itwas their participation, discussions, review and comments thatmade this publication the advancement of the profession and its of ContentsEngineering OnePiping ThreePiping FourExpansion / Contraction ..Section FiveBest SixQuick Pick SevenHFC Quick Pick Tables ..Section EightHCFC Quick Pick Tables ..Section NineCFC Quick Pick Tables ..Section TenSuvarefrigerants Engineering DataSection 1 Engineering DataSuvarefrigerants Section 1 page .. 1 Engineering Data .. Section OneDesign Goals ..page 3 Application Considerations ..page 5 Code Regulations ..page 6 General Design Principles.

2 Page 7 Capacity versus Pressure Drop ..page 8 Equivalent Lengths ..page 9 Copper Tubing Specifications ..page 10 Weight of Refrigerant in Copper ..page 11 Refrigerant Receivers ..page 12 Temperature / Pressure tables ..page 13 Refrigeration Piping Schematics ..page 14 TEL Work Sheets ..page 16 Glossary of Terms ..page 18 Suvarefrigerants Section 1 page .. 2 Refrigerant PipingDesign GoalsA common goal is to size the Suction, Hot Gas and Liquidlines for about 1F pressure drop at design Suction line must: return oil from the evaporator to thecompressor at minimum system capacity. prevent oil draining from an active to aninactive evaporator when more than oneevaporator is used in a single system. dampen or eliminate line vibrations and noisecause by compressor vibration. minimize line sweating from condensation. prevent unnecessary heat gain into Hot Gas Discharge line must: avoid oil trapping at minimum systemcapacity.

3 Prevent backflow of oil or liquidrefrigerant to the compressor during lowcapacity or shutdown. dampen or eliminate line vibration andnoise caused by gas pulsations andcompressor ..Suvarefrigerants Section 1 page .. 3 Refrigerant PipingDesign GoalsThe Liquid line must prevent: formation of flash gas upstream of the meteringdevice. heat gain to the Refrigerant Condensate line must: provide sewer-type flow; that is, free draining ofliquid Refrigerant in one direction, whilerefrigerant vapour flows adjacent to the liquid inthe other Hot Gas Defrost line must: maintain sufficient Refrigerant flow rate. Thevelocity determined at saturated conditionswill result in a conservative line size. be properly sized to handle the calculatedneeded hot gas load, this is based on twice theevaporator flow rate. prevent condensed liquid Refrigerant frombackflow to the compressor while on defrost refrigeration Piping design requires that the refrigeration lines be pitched in the direction of flow atapproximately 1/2 inch per 10 feet or 1 inch per 20 velocities in vertical lines should be at least 1500 ft/min to ensure good oil return;velocities in horizontal lines should be at least 750 Section 1 page.

4 4 Refrigerant PipingApplication Considerations System design for MINIMUM pressure loss results in:a. decrease in thermal capacityb. increase power requirements (see page 8) Refrigerant being piped DOES NOT change state. Lubricants are miscible with refrigerants. minimize the accumulation of liquidrefrigerant in compressor crankcase oil returns to compressor at same ratewhich it leavesSuvarefrigerants Section 1 page .. 5 Refrigerant PipingCode RegulationsDesign should conform to all codes, law and regulations thatapply at the SITE of the :Mechanical Refrigeration Code .. CSA B52 Canadian Building CodeASHRAE 15 Municipal / State / Provincial CodesOEM s Recommended Installation GuidelinesSuvarefrigerants Section 1 page .. 6 Refrigerant PipingGeneral Design Principles Ensure proper feed to evaporators. Practical line sizes without excessive pressure drop. Protect compressor by: preventing excessive oil from being trapped in asystem.

5 Minimizing oil loss from the compressor. preventing liquid Refrigerant or oil from entering thecompressor while operating or while on the off cycle. maintaining a clean and dry Section 1 page .. 7 Refrigerant PipingCapacity Versus Line Pressure DropVapour LinesNo line loss2F Suction line2F Hot gas discharge line4F Suction line4F Hot gas discharge lineCapacity % % LinesPressure drop not as critical as in vapour drop should not cause: vapour formation in line insufficient liquid pressure at DX deviceTypical liquid line pressure drop no greaterthan 1F change in Refrigerant Section 1 page .. 8 Refrigerant 5 1 5 1 5 3 1 Line /SightGlass45 Elbow90 LRElbow90 SRElbowAngle /CheckValveGlobe /SolenoidValve Line SizeODEquivalent Lengths of Nonferrous Valves and FittingsEquivalent Length is expressed in Feet of PipeMuller Brass Co. DataSuvarefrigerants Section 1 page .. 9 Note: General accepted industry practice for determining the equivalent lengths for both P traps and U Bends is to add two 90 LR elbows of the specific OD tubing size for each component CouplingReducing Coupling1/41/23/41/41/23 Engineering Manual number 3 Enter table for losses at smallest diameter d Areasq.

6 (OD)Diameter3/81/25/83/47/81 1/81 3/81 5/82 1/82 5/83 1/83 5/84 1/8 DiameterOD In ID InBased on ASTM B-88 standardRefrigerant PipingCopper Tubing SpecificationsSuvarefrigerants Section 1 page .. 105678910111213145/87/81 1/81 3/81 5/82 1/82 5/83 1/83 5/84 1/8 Max. Spanin (OD)DiameterMaximum Spacing Between PipeSupports for Copper Tubing1967 ASHRAE Guide and Data Book{{ Maximum allowable hanger distance as per CSA B52 code 1/81 3/81 5/82 1/82 5/83 1/83 5/84 1 VNOTES: (1).}}

7 L .. saturated liquid & density, V .. saturated vapour & density, (2). Copper Tubing as per ASTM B88, (3). for R-507 use R-404A of Refrigerant in Copper TubingPounds per 100 feet of Type K & L Tubing ( Weight at 77 F / 25 C )Tube Areasq. inCu ft /100ft(2)(1)(3)

8 Section 1 page .. 11 Refrigerant Receivers( R-22 capacities at 90 F and 90% full. )Density of R-22 at 90 F is lbs per cubic footVertical Receivers( R-22 capacity in lbs. )Horizontal Receivers( R-22 capacity in lbs. )Dia. length x = x 10 = 34 x 10 = 45 x 10 = 65 x 20 = 136 x 12 = 106 x 18 = 166 x 24 = 226 x 30 = 28 Dia. length x 28 = 186 x 30 = 286 x 36 = 346 5/8 x 38 = 437 5/8 x 28 = 418 5/8 x 28 = 538 5/8 x 36 = 698 5/8 x 42 = 818 5/8 x 48 = 938 5/8 x 60 = 117 Dia. length 3/4 x 22 = 5110 3/4 x 36 = 10510 3/4 x 48 = 14210 3/4 x 60 = 17910 3/4 x 72 = 21610 3/4 x 96 = 29012 3/4 x 48 = 19612 3/4 x 60 = 24812 3/4 x 72 = 29912 3/4 x 96 = 404 Dia. length x 72 = 36314 x 96 = 48916 x 60 = 38816 x 72 = 47016 x 96 = 63318 x 72 = 59720 x 72 = 73620 x 84 = 86620 x 96 = 996 For alternate Refrigerant storage capacities in pounds for R-22 rated receiversmultiply the rated capacity by the following conversion factors.

9 Example: A receiver that measures 12 3/4" x 72" has a R-22 rated capacity of 299 is its revised capacity if this receiver is used with R- 407c ?299 lbs x = 283 .. R-401A .. R-404A .. R-410A .. R-401B .. R- 407c .. R-507 .. R-402A .. R-408A .. R-402B .. R-409A .. : Receivers capacities source .. Standard Refrigeration Company. All dimensions are expressed in inches and all weights are expressed in pounds. Densities sourced from DuPont Thermodynamic Tables, R-507 .. AlliedSignal Inc., computer program, R-408A and R-409A .. Elf Atochem, computer Section 1 page .. 12 Note: Dia. and Length are in inches Note: Dia. and Length are in inches 344 52368 54392 57418 60446 63445479510543577315 282336 302358 324381 347405 372333 331355 353378 377403 401428 4221841992132292463013213413633852782963 16337359125 169130 181135 193140 207145 220243 38261 41280 43300 46322 49320344368394421222 193239 209257 225275 243294 262237 235254 252273 271292 290312 3101241351461581712162322482652821962102 26242260100 117105 127110 136115 147120 158166 24180 27194 29210 32226 35221238257277298151 126163

10 138177 150191 164206 178162 160176 177190 188205 203220 2187987951041141491611741872011321441561 6818275 7780 8485 9290 10095 108108 10119 13129 16141 18153 2114515817318820496 77106 86116 95127 104139 115106 104116 114126 125138 136150 1484652586471981071171271388493102111122 50 4755 5260 5765 6470 7066 - 473 - 181 290 499 7899910912113257 4364 4871 5579 6287 6964 6371 7079 7887 8696 9522263135405966738189495562697625 2530 2935 3340 3745 4235 -1841 -1546 -1252 - 959 - 7505764728029 1934 2339 2744 3250 3734 3339 3845 4451 4957 5679121519313641465224283338430 95 1210 1515 1820 2115 -3218 -2922 -2626 -2331 -21232832384410 414 617 921 1225 1514 1317 1621 2025 2429 28 7 4 0241215192227710131620-25 2 -20 1-15 2-10 5- 5 5 R-507 C1 -463