1、Designation: F 2682 07Standard Guide forDetermining the Buoyancy to Weight Ratio of Oil SpillContainment Boom1This standard is issued under the fixed designation F 2682; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide describes a practical method for determiningthe buoyancy to weight (B/W) ratio of oil spill containmentboom
3、s.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility 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
4、 Documents2.1 ASTM Standards:2F 818 Terminology Relating to Spill Response BarriersF 1523 Guide for Selection of Booms in Accordance WithWater Body Classifications3. Terminology3.1 boom sectionlength of boom between two end con-nectors. F 8183.2 boom segmentrepetitive identical portion of the boomse
5、ction. F 8183.3 buoyancy to weight ratiogross buoyancy divided byboom weight. F 8183.4 gross buoyancyweight of fresh water displaced by aboom totally submerged. F 8183.5 reserve buoyancygross buoyancy minus boomweight. F 8184. Significance and Use4.1 This guide describes a method of determining theb
6、uoyancy to weight ratio of spill response booms. The prin-ciple is based on Archimedes Law, which states that a bodyeither wholly or partially immersed in a fluid will experiencean upward force equal and opposite to the weight of the fluiddisplaced by it.4.2 Unless otherwise specified, when used in
7、this guide, theterm buoyancy to weight ratio (B/W ratio) refers to the grossbuoyancy to weight ratio. Buoyancy is an indicator of a spillresponse booms ability to follow the water surface whenexposed to current forces, fouling due to microbial growth(which adds weight), and wave conditions. Surface
8、conditionsother than quiescent will have an adverse effect on collection orcontainment performance. When waves are present, conform-ance to the surface is essential to prevent losses. Minimumbuoyancy to weight ratios for oil spill containment booms arespecified in Guide F 1523 for various environmen
9、tal condi-tions.4.3 This guide provides the methodology necessary todetermine the buoyancy to weight ratio using a fluid displace-ment method. This method is typically applied to boomshaving relatively low B/W ratios (in the range of 2:1 to 10:1).Booms with greater buoyancies may also be tested in t
10、hismanner. It is acceptable to use calculation methods to estimateboom displacement for booms with buoyancies greater than10:1, where the potential error in doing so would have a lesssignificant effect on performance.4.4 When evaluating the B/W ratio of a spill response boom,consideration must be gi
11、ven to the inherent properties of theboom that may affect the net B/W ratio while in use. Theseconsiderations include, but are not limited to, absorption offluids into flotation materials, membranes that are abradedduring normal use, and entry of water into components of theboom.4.5 The entry of wat
12、er into boom components is of particu-lar concern with booms that contain their flotation elementwithin an additional membrane. (This is the case for manybooms that use rolled-foam flotation and relatively lightweightmaterial for the boom membrane.) It is also important forbooms that have pockets th
13、at enclose cable or chain tensionmembers or ballast. When new, the membrane enclosure maycontain air that would result in increased buoyancy. In normaluse, the membrane material may be easily abraded such that itwould no longer contain air, and water would be allowed in atabrasion locations. For suc
14、h booms, the membrane enclosureshall not be considered as part of the flotation of the boom, andthe membrane shall be intentionally punctured to allow waterto enter during the test procedure.1This guide is under the jurisdiction of ASTM Committee F20 on HazardousSubstances and Oil Spill Response and
15、 is the direct responsibility of SubcommitteeF20.11 on Control.Current edition approved Nov. 1, 2007. Published November 2007.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
16、 refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Summary of Test Method5.1 Displacement MethodBuoyancy to weight ratio isestimated using two key values, the dry weigh
17、t of the boomand the gross buoyancy of the boom. Weight of the boom ismeasured directly. The gross buoyancy is equal to the weight offresh water displaced by a boom totally submerged. Grossbuoyancy is measured by submerging the boom, measuring thevolume of water that is displaced, and calculating th
18、e weight ofthe displaced water.6. Equipment Requirements6.1 This method requires a scale to measure the dry weightof the boom, an open-top tank sufficient in volume andfootprint area to physically hold the boom section or segment,a means of submerging the test section, a fresh water supply,and a met
19、hod of accurately measuring the volume of water thatis delivered to the tank. A recommended method of restrainingthe booms buoyant force is to use a fabricated grid ofdimensional lumber or steel that fits inside the tank surfacearea.6.2 The preferred method of determining the displacementof the boom
20、 is to use a complete boom section including endconnectors, tension members and ballast, and so forth. Depend-ing on the size of the boom, it may be more practical tomeasure only a portion of the boom (several segments, forexample) and to scale the results. It is helpful, but not essential,that the
21、tank have a consistent cross-sectional area. Prior to use,the tank shall be leveled and a datum established from whichto obtain relative measurements.6.3 For accurate results, the surface area of the tank shall notgreatly exceed the area that the boom occupies within the tank.A recommended rule-of-t
22、humb for this is that the surface areaof the tank be no greater than twice the area occupied by theboom or boom segments being tested.7. Test Method7.1 The following is a summary of the methodology formeasuring buoyancy-to-weight ratio. The methodology is in-tentionally generalized to allow the user
23、 to employ alternativetest apparatus that may be readily available.7.2 Obtain the dry weight of the boom to be tested (section,segments, and/or components) and record the weight.7.3 Inspect the boom for areas that may trap air during thetest. These include: ballast chain pocket, layers of fabric sow
24、ntogether, and voids at hinges, connectors, and flotation cham-bers. A means of allowing water to fill these air pockets mustbe provided for accurate results.7.4 Place the boom within the (empty) tank, orientating it ina close to upright position as it would be deployed for use.When placing the boom
25、 in the tank, care shall be taken to notintroduce folds in the boom skirt that could trap air, andorienting the boom in a close to upright position is recom-mended to aid in this.7.5 Place the submerging grid (or other device to restrainthe boom below water) in position. There shall be enoughspace f
26、or the boom to float freely as the tank is filled.7.6 Fill the tank with water and allow sufficient time fortrapped air to escape. Filling the tank to submerge the boomshall take no less than one hour, during which time the flotationelement and the skirt shall be moved around to facilitate thereleas
27、e of trapped air. (Note that this must be done periodically,and will be difficult or impossible once the boom is submergedand its buoyant force is holding the boom against the restrain-ing grid.)7.7 Once the boom and the restraining grid have beensubmerged, record the volume of water that has been d
28、eliveredand mark the water level from the datum.7.8 Remove the boom from the tank and empty the tank.With the boom removed and the restraining grid back in place,fill the tank again to the same water level. Record the volumeof water that is delivered to achieve this. The differencebetween this and t
29、he measurement in 7.7 will be the displace-ment of the boom.8. Accuracy8.1 Given the use of the data, a reasonable goal in this testwould be to achieve an accuracy of the buoyancy-to-weightratio of less than 610 %. With an accurate and recentlycalibrated load cell, the tester should be able to deter
30、mine theweight of the boom to within less than 61 %. Therefore, themain test requirement is to measure the buoyancy of the boomto an accuracy of less than 610 %.8.2 The required accuracy has implications for equipmentselection, particularly the test tank. Assuming that the waterlevel can only be mea
31、sured to an accuracy of 61 mm (orapproximately116 in.), the tester can estimate the correspond-ing accuracy of the measured water volume. This shall becompared with the estimated volume measurement of the boom(see 7.8) to ensure that it is within the required 610 %.8.3 Accurately measuring the water
32、 level is critical to anaccurate estimation of the booms displacement. One method isto scribe a datum mark at an appropriate height, and use thedatum as the “fill” mark. Alternatively, a scaled ruler can bemounted at an appropriate location. In both cases, it is essentialthat the test tank be undist
33、urbed through the test period so thatsuccessive tests, and duplicate test runs to establish accuracy,can be performed using the same datum. Whatever the mea-surement method used, the tester shall confirm through dupli-cate tests that the selected method achieves the requiredaccuracy.8.4 Totalizing f
34、low meters are available with a statedaccuracy of 62 %, and can be installed on the water supply (tothe tank) to provide an accurate estimate of the total volume ofwater delivered to the tank. Duplicate tests shall be performedto confirm the required accuracy.9. Potential Sources of Error9.1 The fol
35、lowing items are the most likely sources ofpotential error, other than error due to imprecise measurementtechniques. The tester shall be aware of, and take appropriateprecautions for, each of these items.9.2 The most likely source of error is related to the potentialtrapping of air between flotation
36、 chambers or within folded-over portions of the skirt or sail. Trapped air would lead to anincrease in apparent buoyancy. As noted above, the boom mustbe observed periodically as the tank is filled, and the boommust be manually agitated to ensure that trapped air is freedF2682072from the boom. This
37、means that the filling process shall bedone over a period of no less than one or two hours to allowample time for inspection and agitation of the boom.9.3 If the tank used for the displacement measurement hasremovable or hinged doors, leakage from the tank may be ofconcern. If leakage cannot be stop
38、ped or controlled it may bepossible to collect any such leakage and its volume taken intoaccount in the displacement measurement.9.4 If the boom being tested has been used previously, itsweight may be affected by water trapped within the boom or bythe presence of marine growth.9.5 If the boom being
39、tested is less than a full section, theweight and displacement of the connectors shall be adjustedproportionately.10. Calculation Methods10.1 Calculation methods for estimating boom displacementare acceptable for booms with buoyancies greater than 10:1,where the potential error in doing so would hav
40、e a lesssignificant effect on boom performance. Calculation methodsare also acceptable for booms that are self-inflating, and boomsthat have a continuous buoyancy chamber, where it would bedifficult to measure by the above displacement method.10.2 Calculations are made to estimate the displaced vol-
41、ume of each of the components of a boom section. As with thedisplacement method, components that may not contribute tobuoyancy during normal use shall not be included, specifically,membranes containing solid flotation that may lose theirbuoyant effect when abraded during normal usage.10.3 When calcu
42、lating displacement volumes, care must betaken to account for reductions in cross-section of the flotationelement. For example, flotation chambers may be tapered,greatly reduced, or eliminated at the end of each segment orsection, and this shall be accounted for in the displacementcalculation.10.4 C
43、alculations will lead to a total displacement volume,which is then multiplied by the density of fresh water to resultin total buoyancy in pounds. Total buoyancy is then divided bygross dry weight to produce the buoyancy-to-weight ratio.11. Keywords11.1 boom; buoyancy; oil spill control equipment; oi
44、l spillresponse; spill containmentASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risko
45、f infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this
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47、ur views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F2682073
