1、Designation: F2682 07 (Reapproved 2012)1Standard Guide forDetermining the Buoyancy to Weight Ratio of Oil SpillContainment Boom1This standard is issued under the fixed designation F2682; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorial changes were made to Sections 3, 6, 7, and 9.1. Scope1.1 This guide describes a practical method fo
3、r determiningthe buoyancy to weight (B/W) ratio of oil spill containmentbooms.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 deter
4、mine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F818 Terminology Relating to Spill Response BarriersF1523 Guide for Selection of Booms in Accordance WithWater Body Classifications3. Terminology3.1 boom sectionlength of boom between two end co
5、n-nectors. F8183.2 boom segmentrepetitive identical portion of the boomsection. F8183.3 buoyancy to weight ratiogross buoyancy divided byboom weight. F8183.4 gross buoyancyweight of fresh water displaced by aboom totally submerged.3.5 reserve buoyancygross buoyancy minus boomweight. F8184. Significa
6、nce and Use4.1 This guide describes a method of determining thebuoyancy 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 fl
7、uiddisplaced by it.4.2 Unless otherwise specified, when used in 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 mi
8、crobial growth(which adds weight), and wave conditions. Surface conditionsother than quiescent will have an adverse effect on collection orcontainment performance. When waves are present, confor-mance to the surface is essential to prevent losses. Minimumbuoyancy to weight ratios for oil spill conta
9、inment booms arespecified in Guide F1523 for various environmental conditions.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
10、to 10:1).Booms with greater buoyancies may also be tested in thismanner. 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 t
11、he B/W ratio of a spill response boom,consideration must be given 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
12、entry of water into components of theboom.4.5 The entry of water 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
13、 membrane.) It is also important forbooms that have pockets that 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 ai
14、r, and water would be allowed in at1This guide is under the jurisdiction of ASTM Committee F20 on HazardousSubstances and Oil Spill Response and is the direct responsibility of SubcommitteeF20.11 on Control.Current edition approved June 1, 2012. Published June 2012. Originallyapproved in 2007. Last
15、previous edition approved in 2007 as F2682 07. DOI:10.1520/F2682-07R12E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe
16、ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.abrasion locations. For such booms, the membrane enclosureshall not be considered as part of the flotation of the boom, andthe membrane shall be intentionally punctured to
17、allow waterto enter during the test procedure.5. Summary of Test Method5.1 Displacement MethodBuoyancy to weight ratio isestimated using two key values, the dry weight of the boomand the gross buoyancy of the boom. Weight of the boom ismeasured directly. The gross buoyancy is equal to the weight off
18、resh water displaced by a boom totally submerged. Grossbuoyancy is measured by submerging the boom, measuring thevolume of water that is displaced, and calculating the weight ofthe displaced water.6. Equipment Requirements6.1 This method requires a scale to measure the dry weightof the boom, an open
19、-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 method of accurately measuring the volume of water thatis delivered to the tank. A recommended method of restrainingthe booms buoyant for
20、ce is to use a fabricated grid ofdimensional lumber or steel that fits inside the tank surfacearea. The grid would be positioned above the boom such thatit holds the boom underwater when the tank is filled.6.2 The preferred method of determining the displacementof the boom is to use a complete boom
21、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 tank have a consistent cros
22、s-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-thumb for this is that the s
23、urface 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 to employ alternativetest
24、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 sowntogether, and voids at hin
25、ges, 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, orienting it ina close to upright position as it would be deployed for use.When placing the boom in the tank, care shall be t
26、aken 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 for the boom to float freely a
27、s 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 therelease of trapped air. (Note that
28、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 deliveredand mark the water le
29、vel 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 the measurement in 7.7 will be
30、 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 determine theweight of the boom to
31、 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 measured to an accuracy of 61 mm
32、 (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 level is critical to anaccur
33、ate 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 undisturbed through the test period
34、 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 flow meters are available with
35、 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 following items are the most lik
36、ely sources ofpotential error, other than error due to imprecise measurementtechniques. The tester shall be aware of and take appropriateprecautions for each of these items.F2682 07 (2012)129.2 The most likely source of error is related to the potentialtrapping of air between flotation chambers or w
37、ithin 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 freedfrom the boom. This means that the filling
38、 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 stopped or controlled it m
39、ay 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 tested is less than a
40、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 have a lesssignificant ef
41、fect 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-ume of each of the com
42、ponents 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 calculating displacement vo
43、lumes, 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 Calculations will lead
44、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; oil spillresponse; spill
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48、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F2682 07 (2012)13
