1、Designation: G158 98 (Reapproved 2010)Standard Guide forThree Methods of Assessing Buried Steel Tanks1This standard is issued under the fixed designation G158; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe purpose of this guide is to provide three methods of inspecting and assessing buried steeltank(s) for corrosion damage and de
3、termining the suitability of these tanks prior to application ofcathodic protection.1. Scope1.1 This guide covers procedures to be implemented prior tothe application of cathodic protection for evaluating the suit-ability of a tank for upgrading by cathodic protection alone.1.2 Three procedures are
4、described and identified as Meth-ods A, B, and C.1.2.1 Method ANoninvasive with primary emphasis onstatistical and electrochemical analysis of external site envi-ronment corrosion data.1.2.2 Method BInvasive ultrasonic thickness testing withexternal corrosion evaluation.1.2.3 Method CInvasive perman
5、ently recorded visual in-spection and evaluation including external corrosion assess-ment.1.3 This guide presents the methodology and the proceduresutilizing site and tank specific data for determining a tankscondition and the suitability for such tanks to be upgraded withcathodic protection.1.4 The
6、 tanks condition shall be assessed using Method A,B, or C. Prior to assessing the tank, a preliminary site surveyshall be performed pursuant to Section 8 and the tank shall betightness tested pursuant to 5.2 to establish that the tank is notleaking.1.5 While this guide provides minimum procedures fo
7、rassessing a tanks condition, this guide does not provideminimum installation procedures or requirements for upgradesof the tank by cathodic protection.1.6 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units tha
8、t are provided for information onlyand are not considered standard.1.7 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 ap
9、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 The most recent version of the following documentsshould be consulted as references by those using this guide:2.2 ASTM Standards:2D2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Ro
10、ck by MassE114 Practice for Ultrasonic Pulse-Echo Straight-Beam Ex-amination by the Contact MethodE797 Practice for Measuring Thickness by Manual Ultra-sonic Pulse-Echo Contact MethodE1323 Guide for Evaluating Laboratory Measurement Prac-tices and the Statistical Analysis of the Resulting DataE1526
11、Practice for Evaluating the Performance of ReleaseDetection Systems for Underground Storage Tank Sys-tems3G51 Test Method for Measuring pH of Soil for Use inCorrosion TestingG57 Test Method for Field Measurement of Soil ResistivityUsing the Wenner Four-Electrode Method1This guide is under the jurisd
12、iction of ASTM Committee G01 on Corrosion ofMetals and is the direct responsibility of Subcommittee G01.10 on Corrosion inSoils.Current edition approved Feb. 1, 2010. Published February 2010. Originallyapproved in 1998. Last previous edition approved in 2004 as G15898(2004). DOI:10.1520/G0158-98R10.
13、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 ASTM website.3Withdrawn. The last approved version of this historical stan
14、dard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.3 ASNT Standard:4ASNT SNT-TC-1A Personnel Qualification and Certifica-tion in Nondestructive Testing2.4 NACE International Standards:5RP-0169 Standar
15、d Recommended Practice-Control on Ex-ternal Corrosion on Underground or Submerged MetallicPiping SystemsRP-0187 Standard Recommended Practice-Design Consid-erations for Corrosion Control of Reinforcing Steel inConcreteRP-0285 Standard Recommended Practice-Corrosion Con-trol of Underground Storage Ta
16、nk Systems by CathodicProtection2.5 Environmental Protection Agency Methods:6EPA SW 846 Test Methods for Evaluating Solid WasteEPA 371.1 Measurement of Sulfate Reducing Bacteria2.6 National Fire Protection Association (NFPA)7NFPA 329 Recommended Practice for Handling Under-ground Releases of Flammab
17、le and Combustible Liquids2.7 Underwriters Laboratories Inc.8UL 58 Steel Underground Tanks for Flammable and Com-bustible Liquids3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 buriedto be placed in the ground and covered withearth.3.1.2 cathodic protectionan applied technique
18、 to preventfurther corrosion of a metal surface by making that surface thecathode of an electrochemical cell. For example, a tank systemcan be cathodically protected through the application of eithergalvanic anodes or impressed current.3.1.3 corrosion specialist/cathodic protection specialistacompet
19、ent person who by reason of knowledge of the physicalsciences and the principles of engineering and mathematics,acquired by education and related practical experience, isqualified to engage in the practice of corrosion control onburied or submerged metallic piping systems and metallictanks. Such per
20、sons shall be registered professional engineersor persons recognized as corrosion specialists or cathodicprotection specialists by NACE, if their professional activitiesinclude suitable experiences in external corrosion control onburied or submerged metallic piping and tanks.3.1.4 corrosion technici
21、ana person possessing basicknowledge of corrosion and corrosion control, who is capableof performing routine, well defined work under the supervisionof the corrosion specialist/cathodic protection specialist.3.1.5 invasive procedurea method of determining thecorrosion status of a tank by assessing t
22、he tank from the insideas part of the upgrade procedure. Further, for the purposes ofthis guide, it does not require manned entry into the tank. (Seenon-invasive.)3.1.6 limitationsThe user of this guide is encouraged toreview any available third party verification information pro-vided as part of th
23、e vendor selection process.3.1.7 noninvasive procedurea method of determining thecorrosion status of a tank from the characteristics of itssurroundings with minimal entry into the tank. Further, for thepurposes of this guide, it does not require manned entry intothe tank. (See invasive.)3.1.8 pHthe
24、numerical value of the negative logarithm ofthe hydrogen ion concentration in moles per litre in anelectrolyte.3.1.9 redox potentialpotential of platinized platinum elec-trode in a redox environment (reversible system). The value ofredox potential depends on whether the system is in theoxidized, par
25、tially oxidized, partially reduced, or reduced state.3.1.10 tank tightness testa method capable of detecting a0.1 gal/h leak rate, while accounting for any applicable effectsof thermal expansion or contraction of the product, of vaporpockets, of tank deformation, of evaporation or condensation,and o
26、f the location of the water table. The method must becapable of detecting a 0.1 gal/h leak rate with a probability ofdetection of at least 0.95 and a probability of false alarm of atmost 0.05 or in accordance with NFPA 329.3.1.11 unconditional probability of corrosion failuretheprobability of corros
27、ion failure which includes a determinationof whether localized, pitting, or general corrosion is occurring.3.1.12 underground storage tank (UST)any one or com-bination of tanks (including connected underground piping),the volume of which is 10 % or more beneath the surface of theground.3.1.13 upgrad
28、ethe addition to or retrofit of UST systemsusing approaches including, but not limited to, cathodic pro-tection to improve the ability of a UST system to prevent arelease.3.1.14 USTsee underground storage tank (see 3.1.12).3.1.15 vendor provided informationThe user is referred toAnnex A1 for a speci
29、fic form and format of information whichmust be provided by a vendor. This information consists ofhistoric performance data on a method and is mandated as partof the guide.4. Significance and Use4.1 This guide provides three methods for determining thesuitability of a buried steel tank to be upgrade
30、d with cathodicprotection.4.2 This guide may be used to assess any UST, includingnon-regulated USTs.4.3 This guide provides three alternative methods but doesnot recommend any specific method or application. Theresponsibility for selection of a method rests with the user.4.4 This guide has specific
31、requirements for vendor pro-vided information which should be requested and reviewed bythe user.4Available from TheAmerican Society for Nondestructive Testing (ASNT), P.O.Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.5Available from National Association of Corrosion Engineers (NACE), 1440So
32、uth Creek Dr., Houston, TX 77084-4906.6Available from US Environmental Protection Agency, Office of UndergroundStorage Tanks, 401 “M” St. SW, Washington, DC 20460.7Available from Underwriters Laboratories (UL), Corporate Progress, 333Pfingsten Rd., Northbrook, IL 60062.8Available from National Fire
33、Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02269-9101.G158 98 (2010)25. Permits, Plans and Tank Leak Testing5.1 Prior to engaging in any activities relating to thealteration, repair, or upgrade of any UST system, consult allnecessary authorities to obtain any required permits.5.2
34、Tank Leak Testing:5.2.1 To establish that tanks are not leaking prior to assess-ment, they shall be assessed by a leak detection system. Thisleak detection assessment alone is not sufficient to determinethat a tank is suitable for upgrading with cathodic protectionunder this guide.5.2.2 A tightness
35、test or another release detection system inaccordance with NFPA 329 shall be used. Any release detec-tion must be capable of detecting a leak from any portion of thetank that routinely contains product, and be independentlyevaluated and certified in accordance with Practice E1526 orthe equivalent. L
36、eak detection results shall be provided to thecorrosion specialist/cathodic protection specialist.5.2.3 This testing shall be accomplished within six monthsprior to performing any of the assessment procedures.6. Required Approvals and Certifications6.1 The corrosion assessment work carried out under
37、 thisguide shall be performed under the responsible direction of acorrosion specialist/cathodic protection specialist as defined in3.1.3.6.2 The corrosion specialist/cathodic protection specialistshall certify to the tank owner or operator that the personnelperforming the assessment work on the tank
38、 are knowledgeableof all the applicable procedures in this guide.6.3 The corrosion specialist/cathodic protection specialistshall certify to the tank owner or operator that all work wasperformed in strict accordance with this guide.7. General Safety Requirements7.1 All personnel shall comply with ap
39、plicable federal,state, and local health and safety codes and regulations.8. Preliminary Site Survey8.1 A corrosion technician, under the responsible directionof the corrosion specialist/cathodic protection specialist, shallobtain tank site specific information as appropriate to themethod of assessm
40、ent to be used.8.1.1 Facility Information:8.1.1.1 Address or location, and8.1.1.2 Name and telephone number of owner and operatorcontact personnel.8.1.2 Tank and Piping Details:8.1.2.1 Number and capacity,8.1.2.2 Location and dimensions,8.1.2.3 Age,8.1.2.4 Material of construction,8.1.2.5 Electrical
41、 isolation,8.1.2.6 Type of product stored,8.1.2.7 Names of site contact personnel,8.1.2.8 Backfill material,8.1.2.9 Coatings and linings,8.1.2.10 Leak history,8.1.2.11 Repair history,8.1.2.12 Site plans,8.1.2.13 Installation specifications,8.1.2.14 Tank excavation liners, and8.1.2.15 As-built drawin
42、gs.8.1.3 Information Not in the Immediate Vicinity of theTanksThe presence of the following items, that are externalto the tank area, shall be investigated and included as appro-priate to the method of assessment of the suitability of tanks forupgrading with cathodic protection:8.1.3.1 Stray dc curr
43、ent sources,8.1.3.2 Existing cathodic protection systems,8.1.3.3 Steel product and vent piping and fittings, and8.1.3.4 Adjacent subsurface metallic/steel-reinforced con-crete structures.8.2 Preliminary EvaluationPrior to assessing the tank, apreliminary site survey must be performed pursuant to Sec
44、tion8 and a tightness test must be performed pursuant to 5.2 toestablish that the tank is not leaking.9. Method ANoninvasive with Primary Emphasis onStatistical and Electrochemical Analysis of ExternalSite Environment Corrosion Data (1, 2)9.1 Field and Laboratory TestingNoninvasive with Pri-mary Emp
45、hasis on Statistical and Electrochemical Analysis ofExternal Site Environment Corrosion Data.9.1.1 Tests shall be conducted by, or as directed by acorrosion specialist/cathodic protection specialist.9.1.2 Field Testing ProceduresTests to be performed shallinclude, but are not limited to, the followi
46、ng:9.1.2.1 Stray CurrentsPerform tests to detect the presenceof stray currents at each tank site. This test shall consist ofmeasuring structure-to-soil potentials at right angles at aminimum of two locations within the tank facilities andobserving the measurements for not less than2hatatimewhen such
47、 influences are most likely to occur. The monitorshall consist of a field data acquisition unit, with a minimum of10-MV input impedance, used in conjunction with a stablereference cell(s) placed in contact with the soil in the vicinityof the tank. The instrument shall measure and store structure-to-
48、electrolyte potential (voltage) data at least every 5 s through-out the entire duration of field investigation at the site or for 2h, whichever is greater. If variations of 650 mV or greater aremeasured during the test period, make 24-h recording measure-ments to confirm stray current effects.9.1.2.
49、2 Tank Information:(a) Locate all tanks and confirm materials of construction,age, capacity, and dimensions. Produce detailed site sketchesdescribing the layout of the UST system and above gradepertinent details for each site.(b) Determine the presence and extent of internal corrosionimmediately below the fill riser. If the depth of corrosionpenetration in the tank shell exceeds 50 % of the tank wallthickness, the UST shall be declared to have failed the test andthe procedure.(c) Determine if the tanks and piping are electricallycontinuous.9.1.2.3 Bore Hole
