ASTM D6157-97

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 6157 – 97
Standard Practice for
Determining the Performance of Oil/Water Separators
Subjected to a Sudden Release
This standard is issued under the fixed designation D 6157; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 1.8 This practice can be used with a variety of hydrocar-
bons. It adopts No. 2 fuel oil with a density of 845 kg/m
1.1 This practice describes the testing procedure, any nec-
3 2
3 (52.73 lb /ft ) and a viscosity of 1.9 to 4.1 centistokes at 40 °C (104 °F) and SAE
m
essary related apparatus and the sampling technique to be used
3 3
90 lubricating oil with a density (See SAE J313) of 930 kg/m (58 lb /ft ) at 15.5
m
in determining the performance characteristics of an oil/water
°C (60 °F) and a viscosity (See SAE J306) of 13.5 to < 24 centistokes at 100 °C (212
separator subjected to the sudden release of a relatively large
°F) as the comparative testing media. It is understood that the results obtained from
quantity of hydrocarbons that may appear in its influent in pure
this practice are only directly applicable to No. 2 fuel oil and SAE 90 lubricating oil
form or at high concentration.
for the tested concentrations and only careful interpolation or extrapolation, or both,
1.2 This practice does not address determining the perfor-
is allowed to other hydrocarbons. Low viscosity or high density hydrocarbons or
mance characteristics of an oil/water separator subjected to
hydrocarbons that contain a larger fraction of highly soluble compounds may need
surface run-off resulting from rain water draining from im-
to be tested separately.
proved or unimproved land. In this case, refer to Practice
D 6104.
NOTE 1—No extrapolation outside the range of the tested influent or
1.3 This practice does not address determining the perfor-
effluent oil concentrations is allowed as performance may not be linear.
Hence, to establish performance at a higher or lower concentration, the
mance characteristics of an oil/water separator subjected to a
separator shall be tested for that specific condition. In addition, linearity
mechanically emulsified influent such as provided by a pump.
must be established prior to using linear interpolation.
1.4 This practice does not investigate the ability of the
separator to handle debris or suspended solids, that is, grit or 1.9 Since regulations are based on effluent total hydrocar-
bon content, this practice does not set forth any lower limits on
tree leaves.
1.5 While the effluent may meet code requirements for total oil particle size for the evaluation of separator efficiency.
However, a standardized means for mixing oil and water shall
oil and grease content, this practice does not address the
presence of soluble organics, that is, benzene, toluene, ethyl- be specified to ensure repeatability. It must be noted however
that smaller particles, having a greater surface area to volume
benzene and xylene (BTEX’s) that may be detected in the
effluent. It also does not make any provisions for the effects of ratio, rise at a slower rate than their larger counterparts. (Guide
F 933 requires that 20 % of all oil particles be smaller than or
detergents, surfactants, soaps or any water soluble matter (that
is, salts) or any portion of an essentially insoluble matter that equal to 50 μm and IMO MEPC 60 (30) does not mention any
may be found in solution on separation. (Effects of certain particle size requirements but asks the user to avoid emulsion
causing chemicals.)
water soluble chemicals or solids may be investigated by
adding them to the water at predetermined constant concentra- 1.10 Although the tests described in this practice intend to
simulate the performance of a separator subjected to a sudden
tions.)
1.6 In order to estimate the effect of water temperature on release, they do not cover all possible applications. It is the end
user’s responsibility to determine whether his separation re-
the performance of the separator, the tests described in this
practice must be performed at two water temperatures. The quirements are within the scope of this practice.
1.11 A product different from the general description herein
selected temperatures must be at least 10 °C (18 °F) apart, with
the temperature ranging from a minimum of 0 °C (32 °F) to a may be tested and found to be in compliance with the
performance criteria set forth.
maximum of 50 °C (122 °F).
1.7 This practice does not make any provisions for the 1.12 The values stated in SI units are to be regarded as the
standard. The inch-pound units given in parentheses are for
variation of pH or temperature during a test run. Refer to
Appendix X1 for further detail. information only.
1.13 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
This practice is under the jurisdiction of ASTM Committee D19 on Water and
is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water. Ray E. Bolz and George L. Tuve, CRC Handbook of tables for Applied
nd
Current edition approved July 10, 1997. Published October 1997. Engineering Science, 2 Edition, CRC Press, 1991.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 6157
responsibility of the user of this standard to establish appro- 3.2.8 release—any sudden discharge of an oily substance
priate safety and health practices and determine the applica- from vessels that are specifically designed to store, contain or
bility of regulatory limitations prior to use. transfer oily products such as storage tanks, pipelines, diked
areas and transfer equipment and which may appear in the
2. Referenced Documents
influent to a separator.
2.1 ASTM Standards:
3.2.9 separator—a flow through primary treatment device
D 1129 Terminology Relating to Water
the primary purpose of which is to separate oil from water.
D 3370 Test Method for Sampling Water
4. Summary of Practice
D 4281 Test Method for Oil and Grease (Fluorocarbon
4.1 The practice evaluates a separator’s ability to inhibit a
Extractable Substances) by Gravimetric Determination
sudden release from escaping into its effluent. For this, a
F 933 Guide for Evaluation of Oil Water Separation for
quantity of hydrocarbon constituting at least the rated oil
Spilled Oil Recovery Applications
storage capacity of the separator is released at the separator’s
D 6104 Practice for Determining the Performance of Oil/
rated flow for the test conditions, either in pure form or mixed
Water Separators Subjected to Surface Run-Off
with water to form a 500 000 mg/L concentration. It is then
2.2 EPA Standards:
immediately followed with fresh water. The corresponding
EPA-413.1, “Methods for Chemical Analysis of Water and
effluent hydrocarbon content is determined by obtaining and
Wastes”, EPA 600/4-79-020
analyzing grab samples.
EPA-413.2, “Methods for Chemical Analysis of Water and
4.2 The data generated in this practice are considered valid
Wastes”, EPA 600/4-79-020
for the separators tested only. However, the results of these
EPA-1664, H-Hexane Extractable Material (HEM) and
tests may be extrapolated to smaller or larger size separators
Silica Gel Treated N-Hexane Extractable Material (SGT-
provided that applicable geometric and dynamic similitude are
HEM) by Extraction and Gravimetry (Oil and Grease and
maintained. Where the use of extrapolation is not applicable,
Total Petroleum Hydrocarbons) EPA-821-B-94-004B
that size unit must be subjected to testing.
2.3 SAE Standards:
4.3 Other concentrations and quantities of hydrocarbons
SAE J306 Axle and Manual Transmission Lubricant Vis-
may be used. However, this shall be noted in the report and
cosity Classification
when referencing this practice.
SAE J313 Surface Vehicle Recommended Practice — (R)
4.4 For the purpose of this test, the water temperature
Diesel Fuels
should be between 50°F and 70°F and the pH of the water
3. Terminology
between 6 and 9.
3.1 Definitions: For definitions of terms used in this prac-
5. Significance and Use
tice, refer to Terminology D 1129.
5.1 The Clean Water Act promulgated the implementation
3.2 Definitions of Terms Specific to This Standard:
of water quality standards and contamination limits for a wide
3.2.1 calibration—the certified evaluation of the accuracy
range of pollutants including oil and grease. Specifically, the
of a measuring instrument as performed by its manufacturer or
USEPA prohibits “the discharges of oil that cause a film or
an independent licensed or accredited third party.
sheen upon or cause discoloration of the surface of the
3.2.2 contaminated run-off—rain water which has collected
water. . .”. Several state and local agencies have adopted this
oily contaminants from the surfaces it came in contact with and
statement in addition to setting concentration limits, that is, 15
which may appear in the influent to a separator. Unlike a
mg/L or even 5 mg/L. The purpose of this practice is to
release, the level of contamination in this case is much lower.
evaluate the performance of a separator in regards to the
3.2.3 effluent—the aqueous release from a separator.
regulations and user requirements when subject to a sudden
3.2.4 flow totalizer—a counter, usually attached to a flow
release. The sudden release may occur in dry weather and local
meter, that evaluates the total volume of the fluid that has
personnel may attempt to hose the contaminated area down or
flowed through over a given time period.
it may occur on a rainy day and enter the separator mixed in
3.2.5 influent—the oily aqueous input to a separator.
with the runoff.
3.2.6 oily discharge—any release of oily contaminants into
5.2 This practice is not applicable if the influent to a
the environment that exceeds the allowable limit.
separator is simply runoff from contaminated rainwater. For
3.2.7 re-entrainment—the condition in which the level of
this case, see Practice D 6104.
contamination of the effluent water of a separator containing oil
5.3 This practice is not applicable if the influent to a
is higher than the influent contamination level due to internal
separator i
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