DuPont 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.

2 1 Engineering Data .. Section OneDesign Goals ..page 3 Application Considerations ..page 5 Code Regulations ..page 6 General Design Principles ..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.

3 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. 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.

4 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 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.

5 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. minimizing oil loss from the compressor. preventing liquid Refrigerant or oil from entering thecompressor while operating or while on the off cycle.

6 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.

7 (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).}}

8 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)

9 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.

10 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. 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.