ASTM D3698-2004(2010) Standard Practice for Solvent Vapor Degreasing Operations《溶剂蒸气脱脂操作方法的标准实施规程》.pdf

1、Designation: D3698 04 (Reapproved 2010)Standard Practice forSolvent Vapor Degreasing Operations1This standard is issued under the fixed designation D3698; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A

2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice recommends work practices for conven-tional vapor degreasing operations utilizing any solvent orsolvent blend that has b

3、een categorized as nonflammable.1.2 This practice is not intended for use in vapor degreasingoperations utilizing flammable (low flash point) solvents or invapor degreasing operations utilizing enclosed (sealed, air-tight) equipment. For these non-applicable operations, usersshould consult the solve

4、nt or equipment supplier for additionalinformation.1.3 The values given in inch-pound units are to be regardedas the standard. The values stated in parentheses are forinformation only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is ther

5、esponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2110 Test Method for pH of Water Extractions of Halo-genated Organic Solvents and Their

6、 AdmixturesD2942 Test Method for Total Acid Acceptance of Haloge-nated Organic Solvents (Nonreflux Methods)D4276 Practice for Confined Area EntryD4579 Practice for Handling an Acid Degreaser or Still2.2 Government Documents:340 CFR Part 63.460-469 U.S. EPA, National EmissionStandards for Halogenated

7、 Solvent Cleaning29 CFR Part 1910 U.S. Department of Labor, OccupationalSafety and Health Standards2.3 Other Documents:Threshold Limit Values for Chemical Substances and Physi-cal Agents, ACGIH Industrial Ventilation, ACGIH4NFPA 704 Identification System for Fire Hazards of Mate-rials, National Fire

8、 Protection Association53. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 emergencyany occurrence that may result in animmediate hazard to health including exposures resulting from,but not limited to, equipment failure, rupture of containers, orfailure to control equipment.3.1.2

9、 hazardous operationany procedure or activitywhere a release of the solvent or the decomposition products ofthe solvents might be expected to result in a hazard to health.3.1.3 nonflammable solvent(s)as used herein, is a solventor solvent mixture having a NFPA flammability hazard ratingof 1 or lower

10、 (as determined by NFPA 704), intended for use invapor degreasing operations.3.1.4 solvent vapor degreasera solvent and corrosion-resistant tank with a heated solvent reservoir or sump at thebottom, a condensing means near the top, and freeboard abovethe condensing means, in which sufficient heat is

11、 introduced toboil the solvent and generate hot solvent vapor. Because the hotvapor is heavier than air, it displaces the air and fills the tankup to the condensing zone. The hot vapor condenses on thecooled condensing means, thus maintaining a fixed vapor leveland creating a thermal balance.3.1.5 s

12、olvent vapor degreasing operationsthe process bywhich materials are immersed in vapors of boiling liquids forthe purpose of cleaning or altering their surfaces, and are1This practice is under the jurisdiction of ASTM Committee D26 on Haloge-nated Organic Solvents and Fire Extinguishing Agents and is

13、 the direct responsi-bility of Subcommittee D26.02 on Vapor Degreasing.Current edition approved June 1, 2010. Published July 2010. Originally approvedin 1979. Last previous edition approved in 2004 as D3698 04. DOI: 10.1520/D3698-04R10.2For referenced ASTM standards, visit the ASTM website, www.astm

14、.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Code of Federal Regulations, available from U.S. Government Printing Office,Washington, DC 20402.4Available from American Co

15、nference of Governmental Industrial Hygienists,Inc., 1330 Kemper Meadow Dr., Suite 600, Cincinnati, OH 45240.5Available from National Fire Protection Association, 1 Batterymarch Park,Quincy, MA 022699101.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2

16、959, United States.subsequently removed from the vapors, drained and dried in asolvent vapor degreaser.4. Significance and Use4.1 This practice is intended for use by employers indeveloping their own specific operation standards for solventvapor degreasing operations.4.2 Certain vapor degreasing ope

17、rations are subject to therequirements of the National Emission Standards for Haloge-nated Solvent Cleaning (Halogenated Solvent Cleaner NES-HAP) as found in 40 CFR Part 63, Subpart T. The determina-tion of the applicability of these, or any additionalrequirements is the responsibility of the user.4

18、.3 This practice is not intended to address all of therequirements contained in the Halogenated Solvent CleanerNESHAP. Development and implementation of training pro-grams, recordkeeping, and other additional requirements of theNESHAP are the responsibility of the user.5. Exposure Limit5.1 No employ

19、ee may be exposed to any of the solventsutilized in vapor degreasing operations covered by this sectionin excess of either the OSHA Permissible Exposure Limits(PEL), the ACGIH Threshold Limit Value (TLV (trade-marked), or any manufacturers recommended exposure limit.6. System Location and Design6.1

20、Location:6.1.1 Degreasers shall be placed in a room having ventila-tion adequate to maintain operator exposure below the appro-priate exposure limit.6.1.2 A degreaser shall be installed so that it is not affectedby drafts from sources such as windows, doors, fans, unitheaters, ventilators, or adjace

21、nt spray booths. Normal aircirculation (at velocities not exceeding 50 ft (15.24 m)/min) isrecommended and should not be confused with direct draftssuch as those listed in the preceding sentence. Drafts should bediverted from the top of the degreaser by the use of baffleslocated on the windward side

22、 of the degreaser.6.1.3 No degreaser shall be installed in areas where solventvapors may reach open flames or high-temperature surfacesabove 350F (176C). Solvent degreasing equipment shall notbe installed in the proximity of welding and heat treatingoperations or space heaters unless adequate ventil

23、ation of thedegreaser or other means are provided to prevent solvent fumesfrom contacting the high-temperature source.6.1.4 Gas-heated degreasers (provided with natural draftventilation of combustion tube) shall not be located in an areawhere the general mechanical exhaust system produces nega-tive

24、pressure, unless positive exhausting of combustion prod-ucts by mechanical means is provided.6.2 Design:6.2.1 The level of vapors below the top edge of thedegreaser (freeboard) shall at a minimum be a 1.0 ratio ofheight to width.6.2.2 All degreasers shall have durable covers which shallbe secured in

25、 a closed position when degreasing operations arenot occurring. Sliding covers, which allow partial closureduring degreasing operations are preferred.6.2.3 Where gas is used as a fuel for heating, the combus-tion chamber of the degreaser shall be of tight construction,except for such openings as the

26、 exhaust flue, and those that arenecessary for supplying air for combustion. Flues shall be ofcorrosion-resistant construction and shall extend to the outsideair. If mechanical exhaust is used on the flue, there shall beprovision for outside fresh make-up air. If nonmechanicalexhaust is used on the

27、flue, a back draft diverter shall be used.Gas burners shall be provided with safety protection to provideshut down if the pilot or igniter fails.6.2.4 Heating elements shall be so designed and maintainedthat their surface temperature will not cause the solvent ormixture to decompose or break down.6.

28、2.5 New solvent vapor degreasers or solvent stills of morethan 4 ft2of vapor area shall be equipped with suitableclean-out or sludge doors located at the bottom of the boilingsump and any other sump having an area of more than 4 ft2(0.37 m2). These doors shall be designed and gasketed so thatthere w

29、ill be no leakage when they are closed.6.2.6 Floors and platforms around degreasers shall be pre-vented from becoming slippery both by the original type ofconstruction and by frequent cleaning. They shall be firm,sound, and of the design and construction to minimize thepossibility of tripping. Raili

30、ng requirements for platformsappear in 29 CFR 1910.23(c).6.2.7 When an open top degreaser is located in a pit belowfloor level, the elevation of the top of the degreaser shall be aminimum of 42 in. (1066 mm) above the floor level or theoperating level or else a 42-in. (1066-mm) railing must beprovid

31、ed in accordance with 29 CFR 1910.23(c)(3) and(e)(1). Pit ventilation shall be designed to provide a minimumof two air changes per minute whenever a degreaser is installedin a pit more than 18 in. (457 mm) deep.6.2.8 Degreasers shall be equipped with means to preventsolvent vapors from overflowing,

32、such as a vapor level controldevice (vapor safety thermostat) sensitive enough to shut offthe heat input if the solvent vapor level rises above the primarycondensing coils.6.2.8.1 The vapor safety thermostat is typically set at atemperature 20 to 30 % below the boiling point of the solvent(based on

33、the boiling point in F) except for very low boilingsolvents (for example, methylene chloride). For these solvents,the vapor safety thermostat should be set at ambient tempera-ture +10F, but never higher than 100F (38C). Recom-mended temperatures for vapor safety thermostat settings canbe determined

34、fromAppendix X1, or from the solvent supplier.6.2.9 Degreasers shall be equipped with safety devices inthe boiling sump that can shut off the heat input if the solventlevel drops too close to the heating coils (sump level controldevice) or if the solvent becomes too contaminated (sumpsafety thermost

35、at).6.2.9.1 A sump level control device is designed to preventheat input unless there is adequate solvent in the boiling sump.Such devices may be mechanical (liquid level sensor) orthermostatic (liquid level safety thermostat). The liquid levelsensor should interrupt heat input if the liquid level i

36、s less than2 in. above the heating coils. Liquid level safety thermostats,used on electrically heated degreasers, are attached to the upperD3698 04 (2010)2surface of the heating coil with a maximum recommendedsetting of 20F above the boiling point of the solvent.6.2.9.2 Degreasers should also be equ

37、ipped with a sumpsafety thermostat immersed in the boiling liquid. If the de-greaser is equipped with an auxiliary still, then the degreasersump safety thermostat should be set at the temperaturecorresponding to 25 % oil contamination (see 7.4.2.1). Thesump safety thermostat in the auxiliary still s

38、hould then be setat the temperature corresponding to 25 % oil concentration ifthe unit is electrically heated. However, the sump safetythermostat in the auxiliary still can be set at the temperaturecorresponding to approximately 70 % oil concentration if theunit is indirectly heated by such means as

39、 steam. Recom-mended temperatures for the sump safety thermostat can bedetermined from Appendix X1, or from the solvent supplier.6.2.9.3 If reclamation of solvent will be conducted using thedegreasers boiling sump as the still sump, then the safetythermostat in the degreaser may be adjusted to the h

40、ighersetting during that operation and then readjusted to the tem-perature corresponding to 25 % oil concentration during nor-mal operation.6.2.10 Degreasers shall be equipped with a device to pre-vent heat input unless there is adequate cooling to ensuresufficient condensation of vapor in the degre

41、aser.6.2.11 Degreasers of the spray type shall be equipped witha method that will prevent spray pump operation unless thesolvent vapors have reached normal operating levels.6.2.12 Steam-heated degreasers shall be equipped with“ popsafety valves” down-stream from any pressure control. Thepressure rel

42、ief setting should be consistent with the solvent inuse, and may be determined from Appendix X1, or from thesolvent supplier.6.2.13 Conveyorized degreasers shall be equipped with athermostat that will prevent work from being processed bystopping conveyorized operation unless the solvent vaporshave r

43、eached the normal operating levels.7. Degreaser Operations Procedures7.1 Start-UpIn starting a vapor degreaser follow theprocedures enumerated sequentially where applicable:7.1.1 Turn on the cooling/condensing system coolant andcheck to ensure proper operation.7.1.2 Start air exhaust equipment, if a

44、ny.7.1.3 Activate all safety control thermostats.7.1.4 Adjust solvent levels in all compartments as neces-sary.7.1.5 Check that all degreaser covers are in place duringheat-up as well as cool-down.7.1.6 Turn on the heat supply and adjust the settings asnecessary. Adjust the heat balance in the degre

45、aser so that thelevel of the vapor remains constant. A proper balance isachieved if solvent vapors are generated at the same rate theyare condensed by work entering the vapor zone and by thecondensers.7.1.7 Once the vapor level reaches the condensing coils,check to ensure the flow of condensed solve

46、nt through thewater separator and its return to proper degreaser compart-ments.7.1.8 Check all gages and thermometers for proper opera-tion.7.1.9 Begin vapor degreasing of work items.7.1.10 Check condenser coolant flow and adjust coolantflow or temperature, or both, to maintain temperature to ensure

47、that the vapor line does not rise above the condenser and tominimize condensation of moisture from the room air on thecondenser coils. Check that all coolant and heating lines arefree of leaks and the water separator is functioning properly toprevent contamination in the degreaser.7.2 DegreasingIn d

48、egreasing follow the procedures enu-merated:7.2.1 Do not allow work loads to exceed designed degreasercapacity. Work should not generally occupy more than 50 % ofthe open horizontal area of the machine unless the workpermits easy passage of vapor through or around it. Secure ahighly durable tag to e

49、ach degreaser indicating the maximumweight and volume of a single load expressed in terms ofpounds per load and loads per hour.7.2.2 Place work loads, where necessary, in free-drainingnonporous baskets, trays, racks, and so forth, and position toeliminate solvent drag out.7.2.3 When working with cup-shaped parts or parts withcavities that may collect liquid, load the parts, and rotate ifnecessary, in a manner to facilitate complete drainage while inthe vapor zone.7.2.4 Do not allow the vertical rate of entry and withdrawalof work loads to exceed the maximum deg