ASTM D3698-04(2015)
(Practice)Standard Practice for Solvent Vapor Degreasing Operations
Standard Practice for Solvent Vapor Degreasing Operations
SIGNIFICANCE AND USE
4.1 This practice is intended for use by employers in developing their own specific operation standards for solvent vapor degreasing operations.
4.2 Certain vapor degreasing operations are subject to the requirements of the National Emission Standards for Halogenated Solvent Cleaning (Halogenated Solvent Cleaner NESHAP) as found in 40 CFR Part 63, Subpart T. The determination of the applicability of these, or any additional requirements is the responsibility of the user.
4.3 This practice is not intended to address all of the requirements contained in the Halogenated Solvent Cleaner NESHAP. Development and implementation of training programs, recordkeeping, and other additional requirements of the NESHAP are the responsibility of the user.
SCOPE
1.1 This practice recommends work practices for conventional vapor degreasing operations utilizing any solvent or solvent blend that has been categorized as nonflammable.
1.2 This practice is not intended for use in vapor degreasing operations utilizing flammable (low flash point) solvents or in vapor degreasing operations utilizing enclosed (sealed, airtight) equipment. For these non-applicable operations, users should consult the solvent or equipment supplier for additional information.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D3698 − 04 (Reapproved 2015)
Standard Practice for
Solvent Vapor Degreasing Operations
This standard is issued under the fixed designation D3698; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 29 CFR Part 1910 U.S. Department of Labor, Occupational
Safety and Health Standards
1.1 This practice recommends work practices for conven-
tional vapor degreasing operations utilizing any solvent or
2.3 Other Documents:
solvent blend that has been categorized as nonflammable.
Threshold Limit Values for Chemical Substances and Physi-
cal Agents, ACGIH Industrial Ventilation, ACGIH
1.2 This practice is not intended for use in vapor degreasing
operations utilizing flammable (low flash point) solvents or in NFPA 704 Identification System for Fire Hazards of
vapor degreasing operations utilizing enclosed (sealed, air- Materials, National Fire Protection Association
tight) equipment. For these non-applicable operations, users
should consult the solvent or equipment supplier for additional 3. Terminology
information.
3.1 Definitions of Terms Specific to This Standard:
1.3 The values stated in inch-pound units are to be regarded
3.1.1 emergency—any occurrence that may result in an
as standard. The values given in parentheses are mathematical
immediatehazardtohealthincludingexposuresresultingfrom,
conversions to SI units that are provided for information only
but not limited to, equipment failure, rupture of containers, or
and are not considered standard.
failure to control equipment.
1.4 This standard does not purport to address all of the
3.1.2 hazardousoperation—anyprocedureoractivitywhere
safety concerns, if any, associated with its use. It is the
a release of the solvent or the decomposition products of the
responsibility of the user of this standard to establish appro-
solvents might be expected to result in a hazard to health.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 3.1.3 nonflammable solvent(s)—as used herein, is a solvent
or solvent mixture having a NFPA flammability hazard rating
2. Referenced Documents
of 1 or lower (as determined by NFPA 704), intended for use
in vapor degreasing operations.
2.1 ASTM Standards:
D2110 Test Method for pH of Water Extractions of Haloge-
3.1.4 solvent vapor degreaser—a solvent and corrosion-
nated Organic Solvents and Their Admixtures
resistant tank with a heated solvent reservoir or sump at the
D2942 Test Method for Total Acid Acceptance of Haloge-
bottom, a condensing means near the top, and freeboard above
nated Organic Solvents (Nonreflux Methods)
the condensing means, in which sufficient heat is introduced to
D4276 Practice for Confined Area Entry
boilthesolventandgeneratehotsolventvapor.Becausethehot
D4579 Practice for Handling an Acid Degreaser or Still
vapor is heavier than air, it displaces the air and fills the tank
2.2 Government Documents:
up to the condensing zone. The hot vapor condenses on the
40 CFR Part 63.460-469 U.S. EPA, National Emission
cooled condensing means, thus maintaining a fixed vapor level
Standards for Halogenated Solvent Cleaning
and creating a thermal balance.
3.1.5 solvent vapor degreasing operations—the process by
1 which materials are immersed in vapors of boiling liquids for
This practice is under the jurisdiction of ASTM Committee D26 on Haloge-
nated Organic Solvents and Fire Extinguishing Agents and is the direct responsi-
the purpose of cleaning or altering their surfaces, and are
bility of Subcommittee D26.02 on Vapor Degreasing.
subsequently removed from the vapors, drained and dried in a
Current edition approved June 1, 2015. Published June 2015. Originally
solvent vapor degreaser.
approved in 1979. Last previous edition approved in 2010 as D3698 – 04(2010).
DOI: 10.1520/D3698-04R15.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from American Conference of Governmental Industrial Hygienists
the ASTM website. (ACGIH), 1330 Kemper Meadow Dr., Cincinnati, OH 45240, http://www.acgih.org.
3 5
Code of Federal Regulations, available from U.S. Government Publishing Available from National Fire Protection Association, 1 Batterymarch Park,
Office, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://www.gpo.gov. Quincy, MA 02169-7471, http://www.nfpa.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3698 − 04 (2015)
4. Significance and Use 6.2.3 Where gas is used as a fuel for heating, the combus-
tion chamber of the degreaser shall be of tight construction,
4.1 This practice is intended for use by employers in
except for such openings as the exhaust flue, and those that are
developing their own specific operation standards for solvent
necessary for supplying air for combustion. Flues shall be of
vapor degreasing operations.
corrosion-resistant construction and shall extend to the outside
4.2 Certain vapor degreasing operations are subject to the
air. If mechanical exhaust is used on the flue, there shall be
requirements of the National Emission Standards for Haloge-
provision for outside fresh make-up air. If nonmechanical
nated Solvent Cleaning (Halogenated Solvent Cleaner NES-
exhaust is used on the flue, a back draft diverter shall be used.
HAP) as found in 40 CFR Part 63, Subpart T. The determina-
Gas burners shall be provided with safety protection to provide
tion of the applicability of these, or any additional
shut down if the pilot or igniter fails.
requirements is the responsibility of the user.
6.2.4 Heating elements shall be so designed and maintained
4.3 This practice is not intended to address all of the
that their surface temperature will not cause the solvent or
requirements contained in the Halogenated Solvent Cleaner mixture to decompose or break down.
NESHAP. Development and implementation of training
6.2.5 New solvent vapor degreasers or solvent stills of more
programs, recordkeeping, and other additional requirements of
than 4 ft of vapor area shall be equipped with suitable
the NESHAP are the responsibility of the user.
clean-out or sludge doors located at the bottom of the boiling
sump and any other sump having an area of more than 4 ft
5. Exposure Limit 2
(0.37 m ). These doors shall be designed and gasketed so that
there will be no leakage when they are closed.
5.1 No employee may be exposed to any of the solvents
utilized in vapor degreasing operations covered by this section
6.2.6 Floors and platforms around degreasers shall be pre-
in excess of either the OSHA Permissible Exposure Limits vented from becoming slippery both by the original type of
(PEL), the ACGIH Threshold Limit Value (TLV
construction and by frequent cleaning. They shall be firm,
(trademarked)), or any manufacturer’s recommended exposure sound, and of the design and construction to minimize the
limit.
possibility of tripping. Railing requirements for platforms
appear in 29 CFR § 1910.23(c).
6. System Location and Design
6.2.7 When an open top degreaser is located in a pit below
floor level, the elevation of the top of the degreaser shall be a
6.1 Location:
minimum of 42 in. (1066 mm) above the floor level or the
6.1.1 Degreasers shall be placed in a room having ventila-
operating level or else a 42-in. (1066-mm) railing must be
tion adequate to maintain operator exposure below the appro-
provided in accordance with 29 CFR § 1910.23(c)(3) and
priate exposure limit.
(e)(1). Pit ventilation shall be designed to provide a minimum
6.1.2 A degreaser shall be installed so that it is not affected
oftwoairchangesperminutewheneveradegreaserisinstalled
by drafts from sources such as windows, doors, fans, unit
in a pit more than 18 in. (457 mm) deep.
heaters, ventilators, or adjacent spray booths. Normal air
circulation (at velocities not exceeding 50 ft (15.24 m)/min) is 6.2.8 Degreasers shall be equipped with means to prevent
recommended and should not be confused with direct drafts solvent vapors from overflowing, such as a vapor level control
such as those listed in the preceding sentence. Drafts should be device (vapor safety thermostat) sensitive enough to shut off
diverted from the top of the degreaser by the use of baffles the heat input if the solvent vapor level rises above the primary
located on the windward side of the degreaser. condensing coils.
6.1.3 No degreaser shall be installed in areas where solvent
6.2.8.1 The vapor safety thermostat is typically set at a
vapors may reach open flames or high-temperature surfaces
temperature 20 to 30 % below the boiling point of the solvent
above 350°F (176°C). Solvent degreasing equipment shall not
(based on the boiling point in °F) except for very low boiling
be installed in the proximity of welding and heat treating
solvents (for example, methylene chloride). For these solvents,
operations or space heaters unless adequate ventilation of the
the vapor safety thermostat should be set at ambient tempera-
degreaserorothermeansareprovidedtopreventsolventfumes
ture +10°F, but never higher than 100°F (38°C). Recom-
from contacting the high-temperature source.
mended temperatures for vapor safety thermostat settings can
6.1.4 Gas-heated degreasers (provided with natural draft
bedeterminedfromAppendixX1,orfromthesolventsupplier.
ventilation of combustion tube) shall not be located in an area
6.2.9 Degreasers shall be equipped with safety devices in
where the general mechanical exhaust system produces nega-
the boiling sump that can shut off the heat input if the solvent
tive pressure, unless positive exhausting of combustion prod-
level drops too close to the heating coils (sump level control
ucts by mechanical means is provided.
device) or if the solvent becomes too contaminated (sump
safety thermostat).
6.2 Design:
6.2.1 The level of vapors below the top edge of the 6.2.9.1 A sump level control device is designed to prevent
degreaser (freeboard) shall at a minimum be a 1.0 ratio of heat input unless there is adequate solvent in the boiling sump.
height to width. Such devices may be mechanical (liquid level sensor) or
6.2.2 All degreasers shall have durable covers which shall thermostatic (liquid level safety thermostat). The liquid level
be secured in a closed position when degreasing operations are sensor should interrupt heat input if the liquid level is less than
not occurring. Sliding covers, which allow partial closure 2 in. above the heating coils. Liquid level safety thermostats,
during degreasing operations are preferred. usedonelectricallyheateddegreasers,areattachedtotheupper
D3698 − 04 (2015)
surface of the heating coil with a maximum recommended 7.1.8 Check all gages and thermometers for proper opera-
setting of 20°F above the boiling point of the solvent. tion.
6.2.9.2 Degreasers should also be equipped with a sump 7.1.9 Begin vapor degreasing of work items.
safety thermostat immersed in the boiling liquid. If the
7.1.10 Check condenser coolant flow and adjust coolant
degreaser is equipped with an auxiliary still, then the degreaser flow or temperature, or both, to maintain temperature to ensure
sump safety thermostat should be set at the temperature
that the vapor line does not rise above the condenser and to
corresponding to 25 % oil contamination (see 7.4.2.1). The
minimize condensation of moisture from the room air on the
sump safety thermostat in the auxiliary still should then be set condenser coils. Check that all coolant and heating lines are
at the temperature corresponding to 25 % oil concentration if
free of leaks and the water separator is functioning properly to
the unit is electrically heated. However, the sump safety prevent contamination in the degreaser.
thermostat in the auxiliary still can be set at the temperature
7.2 Degreasing—In degreasing follow the procedures enu-
corresponding to approximately 70 % oil concentration if the
merated:
unit is indirectly heated by such means as steam. Recom-
7.2.1 Do not allow work loads to exceed designed degreaser
mended temperatures for the sump safety thermostat can be
capacity.Work should not generally occupy more than 50 % of
determined from Appendix X1, or from the solvent supplier.
the open horizontal area of the machine unless the work
6.2.9.3 If reclamation of solvent will be conducted using the
permits easy passage of vapor through or around it. Secure a
degreaser’s boiling sump as the still sump, then the safety
highly durable tag to each degreaser indicating the maximum
thermostat in the degreaser may be adjusted to the higher
weight and volume of a single load expressed in terms of
setting during that operation and then readjusted to the tem-
pounds per load and loads per hour.
perature corresponding to 25 % oil concentration during nor-
7.2.2 Place work loads, where necessary, in free-draining
mal operation.
nonporous baskets, trays, racks, and so forth, and position to
6.2.10 Degreasers shall be equipped with a device to pre-
eliminate solvent drag out.
vent heat input unless there is adequate cooling to ensure
7.2.3 When working with cup-shaped parts or parts with
sufficient condensation of vapor in the degreaser.
cavities that may collect liquid, load the parts, and rotate if
6.2.11 Degreasers of the spray type shall be equipped with
necessary, in a manner to facilitate complete drainage while in
a method that will prevent spray pump operation unless the
the vapor zone.
solvent vapors have reached normal operating levels.
7.2.4 Do not allow the vertical rate of entry and withdrawal
6.2.12 Steam-heateddegreasersshallbeequippedwith“pop
of work loads to exceed the maximum degreaser design, which
safety valves” down-stream from any pressure control. The
should not exceed 11 ft/min (3.4 m/min).
pressure relief setting should be consistent with the solvent in
7.2.5 Allow the work loads (and accompanying baskets,
use, and may be determined from Appendix X1, or from the
trays, racks, and so forth) to remain in the vapor zone until
solvent supplier.
condensation on the work loads (and accompanying baskets,
6.2.13 Conveyorized degreasers shall be equipped with a
trays, racks, and so forth) has stopped.
thermostat that will prevent work from being processed by
7.2.6 Conduct all spraying of work loads within the vapor
stopping conveyorized operation unless the solvent vapors
zo
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3698 − 04 (Reapproved 2010) D3698 − 04 (Reapproved 2015)
Standard Practice for
Solvent Vapor Degreasing Operations
This standard is issued under the fixed designation D3698; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice recommends work practices for conventional vapor degreasing operations utilizing any solvent or solvent
blend that has been categorized as nonflammable.
1.2 This practice is not intended for use in vapor degreasing operations utilizing flammable (low flash point) solvents or in vapor
degreasing operations utilizing enclosed (sealed, airtight) equipment. For these non-applicable operations, users should consult the
solvent or equipment supplier for additional information.
1.3 The values givenstated in inch-pound units are to be regarded as the standard. The values statedgiven in parentheses are for
information only.mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D2110 Test Method for pH of Water Extractions of Halogenated Organic Solvents and Their Admixtures
D2942 Test Method for Total Acid Acceptance of Halogenated Organic Solvents (Nonreflux Methods)
D4276 Practice for Confined Area Entry
D4579 Practice for Handling an Acid Degreaser or Still
2.2 Government Documents:
40 CFR Part 63.460-469 U.S. EPA, National Emission Standards for Halogenated Solvent Cleaning
29 CFR Part 1910 U.S. Department of Labor, Occupational Safety and Health Standards
2.3 Other Documents:
Threshold Limit Values for Chemical Substances and Physical Agents, ACGIH Industrial Ventilation, ACGIH
NFPA 704 Identification System for Fire Hazards of Materials, National Fire Protection Association
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 emergency—any occurrence that may result in an immediate hazard to health including exposures resulting from, but not
limited to, equipment failure, rupture of containers, or failure to control equipment.
3.1.2 hazardous operation—any procedure or activity where a release of the solvent or the decomposition products of the
solvents might be expected to result in a hazard to health.
3.1.3 nonflammable solvent(s)—as used herein, is a solvent or solvent mixture having a NFPA flammability hazard rating of 1
or lower (as determined by NFPA 704), intended for use in vapor degreasing operations.
This practice is under the jurisdiction of ASTM Committee D26 on Halogenated Organic Solvents and Fire Extinguishing Agents and is the direct responsibility of
Subcommittee D26.02 on Vapor Degreasing.
Current edition approved June 1, 2010June 1, 2015. Published July 2010June 2015. Originally approved in 1979. Last previous edition approved in 20042010 as
D3698 – 04.D3698 – 04(2010). DOI: 10.1520/D3698-04R10.10.1520/D3698-04R15.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Code of Federal Regulations, available from U.S. Government Printing Office, Washington, DC 20402.Publishing Office, 732 N. Capitol St., NW, Washington, DC
20401-0001, http://www.gpo.gov.
Available from American Conference of Governmental Industrial Hygienists, Inc.,Hygienists (ACGIH), 1330 Kemper Meadow Dr., Suite 600, Cincinnati, OH
45240.45240, http://www.acgih.org.
Available from National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269–9101.02169-7471, http://www.nfpa.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3698 − 04 (2015)
3.1.4 solvent vapor degreaser—a solvent and corrosion-resistant tank with a heated solvent reservoir or sump at the bottom, a
condensing means near the top, and freeboard above the condensing means, in which sufficient heat is introduced to boil the solvent
and generate hot solvent vapor. Because the hot vapor is heavier than air, it displaces the air and fills the tank up to the condensing
zone. The hot vapor condenses on the cooled condensing means, thus maintaining a fixed vapor level and creating a thermal
balance.
3.1.5 solvent vapor degreasing operations—the process by which materials are immersed in vapors of boiling liquids for the
purpose of cleaning or altering their surfaces, and are subsequently removed from the vapors, drained and dried in a solvent vapor
degreaser.
4. Significance and Use
4.1 This practice is intended for use by employers in developing their own specific operation standards for solvent vapor
degreasing operations.
4.2 Certain vapor degreasing operations are subject to the requirements of the National Emission Standards for Halogenated
Solvent Cleaning (Halogenated Solvent Cleaner NESHAP) as found in 40 CFR 40 CFR Part 63, Subpart T. The determination of
the applicability of these, or any additional requirements is the responsibility of the user.
4.3 This practice is not intended to address all of the requirements contained in the Halogenated Solvent Cleaner NESHAP.
Development and implementation of training programs, recordkeeping, and other additional requirements of the NESHAP are the
responsibility of the user.
5. Exposure Limit
5.1 No employee may be exposed to any of the solvents utilized in vapor degreasing operations covered by this section in excess
of either the OSHA Permissible Exposure Limits (PEL), the ACGIH Threshold Limit Value (TLV (trademarked)), or any
manufacturer’s recommended exposure limit.
6. System Location and Design
6.1 Location:
6.1.1 Degreasers shall be placed in a room having ventilation adequate to maintain operator exposure below the appropriate
exposure limit.
6.1.2 A degreaser shall be installed so that it is not affected by drafts from sources such as windows, doors, fans, unit heaters,
ventilators, or adjacent spray booths. Normal air circulation (at velocities not exceeding 50 ft (15.24 m)/min) is recommended and
should not be confused with direct drafts such as those listed in the preceding sentence. Drafts should be diverted from the top
of the degreaser by the use of baffles located on the windward side of the degreaser.
6.1.3 No degreaser shall be installed in areas where solvent vapors may reach open flames or high-temperature surfaces above
350°F (176°C). Solvent degreasing equipment shall not be installed in the proximity of welding and heat treating operations or
space heaters unless adequate ventilation of the degreaser or other means are provided to prevent solvent fumes from contacting
the high-temperature source.
6.1.4 Gas-heated degreasers (provided with natural draft ventilation of combustion tube) shall not be located in an area where
the general mechanical exhaust system produces negative pressure, unless positive exhausting of combustion products by
mechanical means is provided.
6.2 Design:
6.2.1 The level of vapors below the top edge of the degreaser (freeboard) shall at a minimum be a 1.0 ratio of height to width.
6.2.2 All degreasers shall have durable covers which shall be secured in a closed position when degreasing operations are not
occurring. Sliding covers, which allow partial closure during degreasing operations are preferred.
6.2.3 Where gas is used as a fuel for heating, the combustion chamber of the degreaser shall be of tight construction, except
for such openings as the exhaust flue, and those that are necessary for supplying air for combustion. Flues shall be of
corrosion-resistant construction and shall extend to the outside air. If mechanical exhaust is used on the flue, there shall be
provision for outside fresh make-up air. If nonmechanical exhaust is used on the flue, a back draft diverter shall be used. Gas
burners shall be provided with safety protection to provide shut down if the pilot or igniter fails.
6.2.4 Heating elements shall be so designed and maintained that their surface temperature will not cause the solvent or mixture
to decompose or break down.
6.2.5 New solvent vapor degreasers or solvent stills of more than 4 ft of vapor area shall be equipped with suitable clean-out
2 2
or sludge doors located at the bottom of the boiling sump and any other sump having an area of more than 4 ft (0.37 m ). These
doors shall be designed and gasketed so that there will be no leakage when they are closed.
6.2.6 Floors and platforms around degreasers shall be prevented from becoming slippery both by the original type of
construction and by frequent cleaning. They shall be firm, sound, and of the design and construction to minimize the possibility
of tripping. Railing requirements for platforms appear in 29 CFR 29 CFR § 1910.23(c).
D3698 − 04 (2015)
6.2.7 When an open top degreaser is located in a pit below floor level, the elevation of the top of the degreaser shall be a
minimum of 42 in. (1066 mm) above the floor level or the operating level or else a 42-in. (1066-mm) railing must be provided
in accordance with 29 CFR 29 CFR § 1910.23(c)(3) and (e)(1). Pit ventilation shall be designed to provide a minimum of two air
changes per minute whenever a degreaser is installed in a pit more than 18 in. (457 mm) deep.
6.2.8 Degreasers shall be equipped with means to prevent solvent vapors from overflowing, such as a vapor level control device
(vapor safety thermostat) sensitive enough to shut off the heat input if the solvent vapor level rises above the primary condensing
coils.
6.2.8.1 The vapor safety thermostat is typically set at a temperature 20 to 30 % below the boiling point of the solvent (based
on the boiling point in °F) except for very low boiling solvents (for example, methylene chloride). For these solvents, the vapor
safety thermostat should be set at ambient temperature +10°F, but never higher than 100°F (38°C). Recommended temperatures
for vapor safety thermostat settings can be determined from Appendix X1, or from the solvent supplier.
6.2.9 Degreasers shall be equipped with safety devices in the boiling sump that can shut off the heat input if the solvent level
drops too close to the heating coils (sump level control device) or if the solvent becomes too contaminated (sump safety
thermostat).
6.2.9.1 A sump level control device is designed to prevent heat input unless there is adequate solvent in the boiling sump. Such
devices may be mechanical (liquid level sensor) or thermostatic (liquid level safety thermostat). The liquid level sensor should
interrupt heat input if the liquid level is less than 2 in. above the heating coils. Liquid level safety thermostats, used on electrically
heated degreasers, are attached to the upper surface of the heating coil with a maximum recommended setting of 20°F above the
boiling point of the solvent.
6.2.9.2 Degreasers should also be equipped with a sump safety thermostat immersed in the boiling liquid. If the degreaser is
equipped with an auxiliary still, then the degreaser sump safety thermostat should be set at the temperature corresponding to 25 %
oil contamination (see 7.4.2.1). The sump safety thermostat in the auxiliary still should then be set at the temperature corresponding
to 25 % oil concentration if the unit is electrically heated. However, the sump safety thermostat in the auxiliary still can be set at
the temperature corresponding to approximately 70 % oil concentration if the unit is indirectly heated by such means as steam.
Recommended temperatures for the sump safety thermostat can be determined from Appendix X1, or from the solvent supplier.
6.2.9.3 If reclamation of solvent will be conducted using the degreaser’s boiling sump as the still sump, then the safety
thermostat in the degreaser may be adjusted to the higher setting during that operation and then readjusted to the temperature
corresponding to 25 % oil concentration during normal operation.
6.2.10 Degreasers shall be equipped with a device to prevent heat input unless there is adequate cooling to ensure sufficient
condensation of vapor in the degreaser.
6.2.11 Degreasers of the spray type shall be equipped with a method that will prevent spray pump operation unless the solvent
vapors have reached normal operating levels.
6.2.12 Steam-heated degreasers shall be equipped with“ pop safety valves” down-stream from any pressure control. The
pressure relief setting should be consistent with the solvent in use, and may be determined from Appendix X1, or from the solvent
supplier.
6.2.13 Conveyorized degreasers shall be equipped with a thermostat that will prevent work from being processed by stopping
conveyorized operation unless the solvent vapors have reached the normal operating levels.
7. Degreaser Operations Procedures
7.1 Start-Up—In starting a vapor degreaser follow the procedures enumerated sequentially where applicable:
7.1.1 Turn on the cooling/condensing system coolant and check to ensure proper operation.
7.1.2 Start air exhaust equipment, if any.
7.1.3 Activate all safety control thermostats.
7.1.4 Adjust solvent levels in all compartments as necessary.
7.1.5 Check that all degreaser covers are in place during heat-up as well as cool-down.
7.1.6 Turn on the heat supply and adjust the settings as necessary. Adjust the heat balance in the degreaser so that the level of
the vapor remains constant. A proper balance is achieved if solvent vapors are generated at the same rate they are condensed by
work entering the vapor zone and by the condensers.
7.1.7 Once the vapor level reaches the condensing coils, check to ensure the flow of condensed solvent through the water
separator and its return to proper degreaser compartments.
7.1.8 Check all gages and thermometers for proper operation.
7.1.9 Begin vapor degreasing of work items.
7.1.10 Check condenser coolant flow and adjust coolant flow or temperature, or both, to maintain temperature to ensure that
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.