ASHRAE 41.4-1996

ASHRAE STANDARDAmerican Society of Heating, Refrigeratingand Air-Conditioning Engineers, Inc.1791 T ullie Circle NE, Atlanta, GA 30329Standard Method for Measurement ofProportion of Lubricant in Liquid RefrigerantBSR/ASHRAE Standard 41.4-1996 (RA 2006)Reaffirmation of ANSI/ASHRAE Standard 41.4-1996Approved by the ASHRAE Standards Committee on October 29, 1995, and reaffirmed on January 21, 2006; by the ASHRAE Board of Directors on February 22, 1996, and reaffirmed on January 26, 2006; and by the American National Standards Institute on May 28, 1996, and reaffirmed on January 27, 2006.ASHRAE Standards are scheduled to be updated on a five-year cycle; the date following the standard number is the year of ASHRAE Board of Directors approval. The latest copies may be purchased from ASHRAE Customer Service, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail: orders@. Fax: 404-321-5478. Tele-phone: 404-636-8400 (worldwide) or toll free 1-800-527-4723 (for orders in US and Canada).© Copyright 2006 ASHRAE, Inc.ISSN 1041-2336When addenda, interpretations, or errata to this standard have been approved, they can be downloaded free ofcharge from the ASHRAE Web site at .SPECIAL NOTEThis American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Consensus is defined by the American National Standards Institute (ANSI), of which ASHRAE is a member and which has approved this standard as an ANS, as “substantial agreement reached by directly and materially affected interest categories. This signifies the concurrence of more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that an effort be made toward their resolution.”Compliance with this standard is voluntary until and unless a legal jurisdiction makes compliance mandatory through legislation.ASHRAE obtains consensus through participation of its national and international members, associated societies, and public review.ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. The Project Committee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAE members, all must be technically qualified in the subject area of the Standard. Every effort is made to balance the concerned interests on all Project Committees.The Manager of Standards of ASHRAE should be contacted for:a. interpretation of the contents of this Standard,b. participation in the next review of the Standard,c. offering constructive criticism for improving the Standard,d. permission to reprint portions of the Standard.ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDSASHRAE Standards and Guidelines are established to assist industry and the public by offering a uniform method of testing for rating purposes, by suggesting safe practices in designing and installing equipment, by providing proper definitions of this equipment, and by providing other information that may serve to guide the industry. The creation of ASHRAE Standards and Guidelines is determined by the need for them, and conformance to them is completely voluntary.In referring to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, either stated or implied, that the product has been approved by ASHRAE.DISCLAIMERASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public in light of available information and accepted industry practices. However, ASHRAE does not guarantee, certify, or assure the safety or performance of any products, components, or systems tested, installed, or operated in accordance with ASHRAE’s Standards or Guidelines or that any tests conducted under its Standards or Guidelines will be nonhazardous or free from risk.ASHRAE STANDARDS COMMITTEE 2005-2006Richard D. Hermans, Chair David E. Knebel, Vice-Chair Donald L. Brandt Steven T. Bushby Paul W. Cabot Hugh F . Crowther Samuel D. Cummings, Jr.Robert G. Doerr Hakim Elmahdy Roger L. Hedrick John F . Hogan Frank E. Jakob Stephen D. KennedyJay A. Kohler James D. Lutz Merle F . McBride Mark P . Modera Cyrus H. Nasseri Stephen V . Santoro Stephen V . Skalko David R. T ree Jerry W. White, Jr.James E. Woods William E. Murphy, BOD ExO Ronald E. Jarnagin, CO Claire B. Ramspeck, Assistant Director of Technology for Standards and Special ProjectsASHRAE Standing Standard Project Committee 41.4Cognizant TC: TC 1.2, Instruments and MeasurementsSPLS Liaison: Bill RichardsDavid A. Didion, Chair*Michael B. Pate*Ullrich Hesse*Roberto Pereira*Daniel C. Leaver*William F . Walter** Denotes members of voting status when the document was approved for publication.--`,,```,,,,````-`-`,,`,,`,`,,`---CONTENTSANSI/ASHRAE Standard 41.4-1996 (RA 2006)Standard Method for Measurement of Proportion ofLubricant in Liquid RefrigerantSECTION PAGE Foreword (2)1 Purpose (2)2 Scope (2)3 Definitions (2)4 List of Required Equipment (2)5 Method of Test (2)6 Test Procedure (4)7 Data to be Recorded (5)8 Calculation of Results (5)9 Symbols (6)10 References (6)Appendix:Recommended Sampling Procedure (6)--`,,```,,,,````-`-`,,`,,`,`,,`---NOTEWhen addenda, interpretations, or errata to this standard have been approved, they can be downloaded free of charge from the ASHRAE Web site at .© Copyright 2006 American Society of Heating,Refrigerating and Air-Conditioning Engineers, Inc.1791 Tullie Circle NEAtlanta, GA 30329All rights reserved.(This foreword is not a part of this standard. It is merely informative and does not contain requirements necessary for conforma nce to the sta nda rd. It ha s not been processed a ccording to the ANSI requirements for a sta nda rd a nd ma y conta in ma teria l tha t ha s not been subject to public review or a consensus process.) FOREWORDThis is a reaffirmation of ASHRAE Standard 41.4-1996. This standard was prepared under the auspices of the Ameri-can Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). It may be used, in whole or in part, by an association or government agency with due credit to ASHRAE. Adherence is strictly on a voluntary basis and merely in the interests of obtaining uniform standards throughout the industry.The change made for the 2006 reaffirmation was that the name of the standard was added to the Contents page.1.PURPOSEThis standard sets forth standard procedures for experi-mentally determining the weight concentration of miscible lubricant-and-liquid-refrigerant mixtures and, in limited cases, immiscible mixtures.2.SCOPE2.1This standard provides a method for measurement of proportion of lubricant in liquid refrigerant.2.2This standarda.defines specialized terms,b.specifies the required data and minimum precision,c.specifies the methods of computation that should be used,andd.describes the equipment required.2.3This standard is intended to apply only where it is known, or possible to determine, that the sample is of a mis-cible lubricant and liquid refrigerant mixture. This restriction is not intended to prevent the application of this standard to determine lubricant concentration in cases where lubricant immiscibility exists provided that the sample is confined entirely to either the lubricant-rich or refrigerant-rich layer.2.4This standard does not apply to measurement of lubri-cant concentrations when the total amount of lubricant col-lected is less than .001 g.2.5This standard provides for a primary (gravimetric) method but does not prohibit the use of other methods using new technologies, provided these methods are calibrated against the primary method.3.DEFINITIONSresolution: the minimum observable difference between two values of a measured characteristic.lubricant concentration, sample basis: the ratio of the weight of lubricant to the total weight of the refrigerant and lubricant in the sample.lubricant concentration, pure refrigerant basis: the ratio of the weight of lubricant to the weight of the pure refrigerant in the sample.4.LIST OF REQUIRED EQUIPMENT1. A high-pressure type 304 stainless steel or aluminum alloycylinder with needle valve. (Stainless steel provides better corrosion resistance but is heavier.) The cylinder shall havea bursting pressure not less than five times the saturationpressure exerted by the refrigerant under test at 60°C.1 The cylinder shall have a rupture disc or a relief valve rated at not more than one-half of the cylinder burst pressure. (See Table 1 or Figure 1 for cylinder sizing.)2.Analytical balance capable of weighing to 0.0001 g.3.Top-loading balance capable of weighing to 0.01 g.4. Pipe thread sealant compatible with the refrigerant/lubri-cant mixture.5. Hot plate.6. Forced-air oven capable of attaining 150°C.7.Filter paper capable of retaining particles ≥3 µm.8.Beakers, 150 mL and 50 mL capacity.9.V acuum pump with gauge capable of measuring vacuumdown to 100 µm Hg.10.Solvent (e.g., pentane and acetone), reagent grade or better.5.METHOD OF TEST5.1This section is a summary of the overall method of test. Details are provided in Section6.The cylinder assembly shall be evacuated and weighed (W1). A sample of liquid whose lubricant content is to be Figure 1Maximum container size.--`,,```,,,,````-`-`,,`,,`,`,,`---T A B L E 1 L u b r i c a n t E s t i m a t e s f o r S a m p l i n g *R e f r i g e r a t o r sS m . U n i t A /C M i d -R a n g e A /C S u p e r m a r k e t . R e f .L a r g e U n i t A /C L g e P k g C h i l l .X -L g e C h i l lC a p a c i t y , k W (t o n s ) 0.7 (0.2)1.76 (0.5) 3.52 (1)17.6 (5) 26.4 (7.5) 70.4 (20) 52.8 (15) 141 (40) 211 (60) 422 (120) 458 (130) 1408 (400) 1760 (500)17600 (5000)E s t . R e f . C h a r g e , k g (l b ) 0.20 (0.44)0.45 (1.0)1.12 (2.5)5.67 (12.5) 8.44 (18.75) 22.70 (50) 17.00 (37.5) 45.4 (100) 68.1 (150)136.2 (300)147.55 (325)454.00 (1000)567.50 (1250)5675(12500)E s t . L u b r i c a n t C h a r g e , L(g a l )0.19 (0.05)0.42 (0.11)0.50 (0.13)2.50 (0.66)3.79 (1.00) 10.0 (2.64) 2.0 (0.53) 5.3 (1.40) 8.0 (2.12) 16.0 (4.25) 17.4 (4.6) 26.5 (7.0)26.5 (7.0)26.5 (7.0)M a x . C o n t a i n e r S i z e , L0.050.050.050.05 0.05 0.15 0.15 0.50 0.50 0.50 0.500.500.500.50L u b r i c a n t i n S a m p l e , g0.10% 0.0430.0430.043 0.043 0.043 0.128 0.128 0.425 0.425 0.4250.4250.4250.4250.4250.20% 0.0850.0850.085 0.085 0.085 0.255 0.255 0.85 0.85 0.850.850.850.850.850.50% 0.2130.2130.213 0.213 0.213 0.638 0.638 2.125 2.1252.1252.1252.1252.1252.1251.00%0.4250.4250.425 0.425 0.425 1.275 1.275 4.25 4.254.254.254.254.254.252.00%0.850.850.85 0.85 0.85 2.55 2.55 8.58.58.58.58.58.58.55.00%2.1252.1252.125 2.125 2.125 6.375 6.375 21.2521.2521.2521.2521.2521.2521.2510.00%4.254.254.25 4.25 4.25 12.75 12.7542.542.542.542.542.542.542.515.00% 6.3756.375 6.375 6.375 6.375 19.13 19.1363.7563.7563.7563.7563.7563.7563.75*T h i s t a b l e i s f o r i n f o r m a t i v e p u r p o s e s o n l y a n d t h e u n i t s h a v e b e e n s e l e c t e d f o r t h e c o n v e n i e n c e o f t h e u s e r .--`,,```,,,,````-`-`,,`,,`,`,,`---determined is drawn into the cylinder and weighed (W 2). The refrigerant is allowed to evaporate slowly so that minimum lubricant is entrained with the leaving vapor. The cylinder shall be evacuated again to strip out remaining refrigerant dissolved in the lubricant.For concentrations ≥1%, the cylinder assembly with the remaining lubricant is reweighed (W 3).For concentrations <1%, the cylinder assembly is washed with solvent. The washings are filtered into a tared beaker (W 4) and the solvent slowly evaporated on a hot plate. The beaker is then reweighed with the remaining oil (W 5). (See Table 3.)The weight of lubricant in the sample is the difference between the third and first weighings (W 3 − W 1) for lubricant concentrations ≥1%, or the difference between the fifth and fourth weighings (W 5 − W 4) for lubricant concentrations <1%.The arithmetic mean of at least three independent deter-minations differing less than 5% shall be the lubricant concen-tration. The lubricant weight concentration shall be expressed as the mean plus or minus (±) three times the standard devia-tion of the mean (SDM) calculated in accord with Section 8.5.2Other secondary test methods may be used, but they shall be calibrated against the primary method over the range of application for verification purposes.6.TEST PROCEDURE 6.1Preparing the Sample Cylinder6.1.1 The cylinder shall be thoroughly cleaned with sol-vent to remove any organic residue. To do this, remove fittings from both ends and remove all sealants. Rinse all parts with solvent, dry in a vented forced-air oven for 15 minutes at 150°C, and reassemble using new sealant.6.1.2 The assembled cylinder shall be heated in a 150°C oven for 15 minutes in order to evacuate to less than 100 µm Hg. Allow to cool to room temperature.6.1.3The cylinder assembly shall be weighed to 0.1 g.Record this weight as (W 1).6.2Sampling6.2.1The maximum weight of sample to be collected shall be determined by multiplying the cylinder volume by 0.8and the density of the liquid refrigerant. (See Table 2.)6.2.2The cylinder assembly shall be connected to the sys-tem at the point where the liquid refrigerant is to be sampled and evacuated via connecting tubing, tee connection, and vac-uum pump. All connecting tubing shall be metal (e.g., soft copper or stainless steel) and shall be kept as short as possible.6.2.3The cylinder assembly shall be placed in an ice bath.6.2.4Close valve to vacuum pump, then open the valve on the cylinder, and finally, open the valve on the system.6.2.5After no more than 80% of the volume of cylinder is filled, the desired amount has been collected, or the maximum weight has been reached, close the valve on the sample source as well as the valve on the cylinder.CAUTION: Lack of sufficient vapor space can create a dangerous overpressure situation if cylinder temperature is increased.6.2.6The connecting tubing shall be carefully discon-nected immediately after sample has been withdrawn to pre-vent overpressurization of liquid line.CAUTION: Liquid refrigerant may be released at this point.Wear protective gloves and safety glasses.6.2.7The cylinder shall be weighed to the nearest 0.1 g and this weight shall be recorded as (W 2). The sample weight shall not exceed the weight determined in 6.2.1. (Note: Cyl-inder surface must be dry.)6.3Separating Refrigerant from Lubricant6.3.1The cylinder shall be connected to the low-pressure side of a recovery system. Consult the pressure-temperature chart for the refrigerant and adjust the cylinder temperature by heating or cooling so that the pressure within the cylinder isTABLE 2 Liquid Densities of Selected Refrigerants(Reference 2)TABLE 3 Detection LimitsNote:This table gives the minimum amounts of lubricant that can be accuratelymeasured using this standard. It includes the assumption that 0.001 g of lubricant is the smallest quantity that can be collected and weighed accurately.--`,,```,,,,````-`-`,,`,,`,`,,`---50 kPA + 15 kPa higher than the lower side pressure of the recovery system being used.6.3.2The valve shall be opened slowly so that only vapor is removed; it shall be left open until outward flow has stopped.6.3.3The cylinder shall be connected to a vacuum pump and evacuated to a pressure of 2000 µm Hg. The valves shall be closed and disconnected from the vacuum pump.6.3.4The mass of the evacuated cylinder shall be deter-mined to ±0.1 g (W3). If the amount of lubricant (W3− W1) is ≤3 g, continue with step 6.3.5. If the amount of lubricant is >3g, the weight of the cylinder shall be recorded as (W3) and then proceed to Section 8.6.3.5If a double-ended cylinder is used, the pipe plug shall be removed from the end of the cylinder. In any case, the inside walls of the cylinder (and the pipe plug) shall be thor-oughly rinsed with reagent-grade solvent to remove any lubri-cant. Pentane is to be used for mineral oil and alkylbenzene. Acetone is to be used for POE and PAG lubricants. Or, alter-natively, a pentane rinse followed by acetone would ensure that all lubricants are removed from the cylinder. The solvent wash shall be collected in a 150-mL beaker. For safety rea-sons, this should be done in a laboratory hood.6.3.6The hot plate shall be used to evaporate the solvent down to 10-20 mL. The temperature of this process should be controlled such that no lubricant is expelled out of the beaker (solvent boiling point is +10°C). The sample shall be trans-ferred into a 50-mL beaker, preweighed to the nearest 0.0001g (W4). If the sample contains solids, it shall be filtered through filter paper capable of retaining particles ≥3 mm. The 150-mL beaker, and filter paper if necessary, shall be rinsed with sol-vent to remove any lubricant left behind.6.3.7The solvent shall be evaporated in the 50-mL beaker down to a few milliliters using a hot plate or preferably an oven set low enough that rapid boiling does not expel lubri-cant out of the beaker. The beaker shall be transferred into a forced-air vented oven set at 121°C for a minimum of two hours to remove the remaining solvent. The beaker shall then be transferred to a desiccator until cool. The beaker contain-ing the lubricant shall be reweighed until constant weight is obtained. This weight shall be recorded as (W5).7.DATA TO BE RECORDEDA form similar to that below should be used for recording original data as they are taken.8.CALCULATION OF RESULTS8.1The concentration of lubricant shall be calculated by the following formulas.8.1.1Sample BasisWhere lubricant 1%Where lubricant 1%8.1.2Pure Refrigerant BasisWhere lubricant 1%Where lubricant 1%8.2Arithmetic Mean Concentration≥C sW3W1–W2W1–--------------------=≤C sW5W4–W2W1–--------------------=≥C RW3W1–W2W3–--------------------=≤C RW5W4–W2W3–--------------------=CC1C2C3. . . C n++n------------------------------------------------=--`,,```,,,,````-`-`,,`,,`,`,,`---8.3Standard Deviation of the Mean9.SYMBOLSW1=weight of the cylinder when emptyW2=weight of the cylinder with sampleW3=weight of the cylinder with residual lubricant from the sampleW4=50-mL beaker (tare weight)W5=50-mL beaker plus remaining lubricantC R=concentration of lubricant based on the weight ofrefrigerant only in the sampleC S=concentration of lubricant based on the weight of therefrigerant and lubricant in the sampleC=arithmetic mean of the independent observations of lubricant concentration in a given sample (C R or C S) n=number of independent observations of lubricant concentration made on a given sample10.REFERENCES1UL 207, “Standard for Safety: Refrigerant Containing Components and Accessories, Nonelectrical,” 5th ed., December, 1986, revised October 3, 1989.2NIST Thermodynamic Properties of Refrigerants and Refrigerant-Mixtures Database (RE F PROP 3.03), Gaithersburg, MD, USA (1991).(This a ppendix is not pa rt of the sta nda rd a nd is provided for information only.)APPENDIXRECOMMENDED SAMPLING PROCEDURE Step 1•Estimate the refrigerant charge in the system.–Avoid removing more than 1% of the system charge by sampling if you intend to continue sys-tem operation.Step 2•The estimated lubricant charge in the system typically will follow the following rules.–For very small systems the typical lubricant charge is 200 mL (approximately 6.7 oz) of oil.–For systems from 3.5 to 422.5 kW (approximately 1 to 120 tons), the estimated lubricant charge is.25lb/nom ton.–F or very large systems above 422 kW (approxi-mately 120 tons), the estimated lubricant charge is26.5 L (7.0 gal).–The idea is to avoid removing too much lubricant charge or refrigerant charge through sampling sothat further system operation could be detrimentalto the equipment. This is particularly true in thesmallest systems.Step 3•Select a sample container size.–This will depend upon the system size (estimated lubricant in system) and the scale accuracy avail-able. (See Figure 1 or Table 1.)–The smallest container size is 50 mL. (This is a practical limit.)–The largest container size is 500 mL to avoid dis-posal problems.Step 4•Examination of Table 1 shows a shaded area.–The shaded area shows when an analytical scale is required to ensure the resolution (0.0001 g).–For the unshaded area, a top-loading scale will pro-vide satisfactory resolution (0.01 g).–Some knowledge of the expected lubricant circula-tion rate is helpful.For rotary compressors in small refrigerators, 1.0%to 1.3% of circulating fluid is oil.For reciprocating compressors, lubricant circulationrates of 0.5% to 1.0% are typical.For large chillers, lubricant circulation rates less than1% are typical.Note: This procedure is usually conducted in an engineering laboratory, so I-P units are included for the user’s convenience.SDM= --`,,```,,,,````-`-`,,`,,`,`,,`---POLICY STATEMENT DEFINING ASHRAE’S CONCERNFOR THE ENVIRONMENTAL IMPACT OF ITS ACTIVITIESASHRAE is concerned with the impact of its members’ activities on both the indoor and outdoor environment. ASHRAE’s members will strive to minimize any possible deleterious effect on the indoor and outdoor environment of the systems and components in their responsibility while maximizing the beneficial effects these systems provide, consistent with accepted standards and the practical state of the art.ASHRAE’s short-range goal is to ensure that the systems and components within its scope do not impact the indoor and outdoor environment to a greater extent than specified by the standards and guidelines as established by itself and other responsible bodies.As an ongoing goal, ASHR AE will, through its Standards Committee and extensive technical committee structure, continue to generate up-to-date standards and guidelines where appropriate and adopt, recommend, and promote those new and revised standards developed by other responsible organizations.Through its Handbook, appropriate chapters will contain up-to-date standards and design considerations as the material is systematically revised.ASHRAE will take the lead with respect to dissemination of environmental information of its primary interest and will seek out and disseminate information from other responsible organizations that is pertinent, as guides to updating standards and guidelines.The effects of the design and selection of equipment and systems will be considered within the scope of the system’s intended use and expected misuse. The disposal of hazardous materials, if any, will also be considered.ASHR AE’s primary concern for environmental impact will be at the site where equipment within ASHR AE’s scope operates. However, energy source selection and the possible environmental impact due to the energy source and energy transportation will be considered where possible. Recommendations concerning energy source selection should be made by its members.--`,,```,,,,````-`-`,,`,,`,`,,`---86107 PC 2/06--` , , ` ` ` , , , , ` ` ` ` -` -` , , ` , , ` , ` , , ` ---。