1、Designation: D1838 12aStandard Test Method forCopper Strip Corrosion by Liquefied Petroleum (LP) Gases1This standard is issued under the fixed designation D1838; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the detection of the presence ofcomponents in liquefied petroleum gases which can be corro-sive to cop
3、per.NOTE 1For an equivalent copper strip test applicable to less volatilepetroleum products, see Test Method D130.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety co
4、ncerns, 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. For specificwarning statements, see 7.1, 10.3.1, and Annex A1.2. Referenced Doc
5、uments2.1 ASTM Standards:2D130 Test Method for Corrosiveness to Copper from Petro-leum Products by Copper Strip TestD1265 Practice for Sampling Liquefied Petroleum (LP)Gases, Manual MethodD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston Cylinder2.2 ASTM Adjuncts:ADJD0130, ASTM Coppe
6、r Strip Corrosion Standard forPetroleum33. Terminology3.1 Abbreviations:3.1.1 CAMICoated Abrasives Manufacturers Institute3.1.2 FEPAFederation of European ProducersAssociation4. Summary of Test Method4.1 A polished copper strip is immersed in approximately100 mL of the sample and exposed at a temper
7、ature of 37.8C(100F) for1hinacylinder of suitable working pressure. Atthe end of this period, the copper strip is removed and rated asone of the four classifications of the ASTM Copper StripCorrosion Standard (ADJD0130).5. Significance and Use5.1 Copper corrosion limits provide assurance that diffic
8、ul-ties will not be experienced in deterioration of the copper andcopper-alloy fittings and connections that are commonly usedin many types of utilization, storage, and transportation equip-ment.6. Apparatus6.1 Corrosion Test Cylinder, constructed of stainless steelwith an O-ring removable top closu
9、re according to the dimen-sions given in Fig. 1. Provide a flexible inert hose, such as onecomposed of aluminum or stainless steel, which permitsinverting the test cylinder as required in the procedure (seeNote 2). The whole assembly, including the corrosion testcylinder, shall be constructed to wit
10、hstand a minimum hydro-static test pressure of 6900 kPa (1000 psig). No leak shall bediscernible when tested at 3450 kPa (500 psig) with gas.NOTE 2Swivel connections with an adapter to fit a 6.4 mm (14 in.)pipe may be used.6.1.1 The assembly shall be tested for compliance with theminimum pressure ra
11、ting of 6900 kPa (1000 psig) by hydro-static testing, or alternative testing protocol acceptable to thelocal authority having jurisdiction, prior to first use. Additionaltesting can be required by the local authority having jurisdic-tion.6.1.2 The assembly shall be verified for gas tightness byleak
12、testing at a minimum of 3450 kPa (500 psig) with inert gasprior to first use, whenever pressure-containing components ofthe assembly are replaced, or otherwise on an annual basis.6.1.3 Note the presence and length (about 60 mm) of theoutage tube shown in Fig. 1, to provide adequate ullage forsafety.
13、 A safety pressure relief device may also be incorporatedinto the design of the corrosion test cylinder, if desired. If a1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum
14、 Gas.Current edition approved Dec. 1, 2012. Published March 2013. Originallyapproved in 1961. Last previous edition approved in 2012 as D183812. DOI:10.1520/D1838-12A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from ASTM International Headquarters. Order Adjunct No.ADJD0130.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, P
16、O Box C700, West Conshohocken, PA 19428-2959. United States1pressure relief device is incorporated, ensure that the materialsof its construction will not affect the test results.6.2 Water Bath, capable of being maintained at 37.8 60.5C (100 6 1F). Incorporate suitable supports to hold thetest cylind
17、er in an upright position. Make the bath deep enoughso that the entire cylinder and valves will be covered during thetest.6.3 Temperature Sensing Device (TSD)Capable of moni-toring the desired test temperature in the bath to within anaccuracy of 60.5C (1F) or better.6.4 Strip Polishing Vise, to hold
18、 the copper strip firmlywithout marring the edges. For convenient vises see TestMethod D130.7. Materials7.1 Wash SolventAny volatile, less than 5 mg/kg sulfur,hydrocarbon solvent may be used provided that it shows notarnish at all when tested for3hat50C (122F). 2,2,4-trimethylpentane (isooctane) of
19、minimum 99.75 % purity is thereferee solvent and should be used in case of dispute.(WarningExtremely flammable, see Annex A1.)7.2 Copper Strip, approximately 12.5 mm (12 in.) wide, 1.5to 3.0 mm (116 to18 in.) thick, cut approximately 75 mm (3 in.)long from smooth-surfaced, hard-temper, cold-finished
20、 copperof 99.9 + % purity; electrical bus bar stock is generallysuitable. Drill a 3.2 mm (18 in.) hole approximately 3.2 mm (18in.) from one end in the center of the strip. The strips may beused repeatedly but should be discarded if surfaces becomedeformed.7.3 Surface Preparation/Polishing Materials
21、00 grade orfiner steel wool; silicon carbide grit paper or cloth of varyingdegrees of fineness including 65-m grade (220-grit CAMI-grade or P220 FEPA-grade); also a supply of 105-m (120-gritto 150-grit CAMI-grade or P120 to P150 FEPA-grade) sizesilicon carbide grain or powder and absorbent cotton. A
22、commercial grade is suitable, but pharmaceutical grade cottonwool is most commonly available and is acceptable.7.4 ASTM Copper Strip Corrosion Standard (ADJD0130),Plaques are available.3Their care and inspection for stabilityare described in detail in Test Method D130.8. Preparation of Strips8.1 Sur
23、face PreparationRemove all surface blemishesfrom all six sides of the strip obtained from a previous analysis.One way to accomplish this is to use 00 grade or finer steelwool or silicon carbide paper or cloth of such degrees offineness as are needed to accomplish the desired resultsefficiently. Fini
24、sh with 65-m grade (220-grit CAMI-grade orP220 FEPA-grade) silicon carbide paper or cloth, removing allmarks that could have been made by other grades of paper usedpreviously. Ensure the prepared copper strip is protected fromoxidation prior to final preparation, such as by immersing thestrip in was
25、h solvent from which it can be withdrawn imme-diately for finish preparation (polishing) or in which it can bestored for future use.8.1.1 Only final preparation (8.2) is necessary for commer-cially purchased pre-polished strips.8.1.2 As a practical manual procedure for surfacepreparation, a sheet of
26、 silicon carbide paper may be placed ona flat surface and then moisten the paper with wash solventbefore rubbing the strip against the silicon carbide paper orcloth with a circular motion. Protect the strip from contact withthe fingers, such as by using ashless filter paper. Alternatively,the surfac
27、e of the strip may be prepared by use of motor-drivenmachines using appropriate grades of dry paper or cloth.8.2 Final PreparationFor strips prepared in 8.1 or newstrips being used for the first time, remove a strip from itsprotected location, such as by removing it from the washsolvent. Polish firs
28、t the ends and then the sides with the105m (120-grit to 150-grit CAMI-grade or P120 to P150FEPA-grade) silicon carbide grains picked up with a pad ofabsorbent cotton moistened with wash solvent, making surethat the surface is protected from coming in contact with thefingers, such as by using ashless
29、 filter paper. Wipe vigorouslywith fresh pads of absorbent cotton and subsequently handlewithout touching the surface of the strip with the fingers.Padded forceps (to prevent the scratching of the surface) havebeen found suitable to use. Secure the copper strip in a vise orsuitable holder and polish
30、 the main surfaces with silicon-carbide grains on absorbent cotton. Do not polish in a circularmotion. Rub in the direction of the long axis of the strip,carrying the stroke beyond the end of the strip before reversingthe direction. Clean all metal dust from the strip by rubbingMetric Equivalentsin.
31、 mm in. mm18 3.2 3 7614 6.4 6 152112 38.1FIG. 1 Copper Strip Corrosion Test CylinderD1838 12a2vigorously with clean pads of absorbent cotton until a fresh padremains unsoiled. When the strip is clean, with minimal delay,attach to the dip tube and lower into the prepared corrosion testcylinder (see F
32、ig. 1).8.2.1 It is important to polish the whole surface of the stripuniformly to obtain a uniformly stained strip. If the edges showwear (surface elliptical) they will likely show more corrosionthan the center. The use of a vise will facilitate uniformpolishing.8.2.2 It is important to follow the o
33、rder of preparation withthe correctly sized silicon carbide material as described in 8.1and 8.2. The final preparation is with 105-m (120-grit to150-grit CAMI-grade or P120 to P150 FEPA-grade) siliconcarbide grains. This is a larger grain size than the 65-m grade(220-grit CAMI-grade or P220 FEPA-gra
34、de) paper used in thesurface preparation stage. The reason for this use of largersilicon carbide grains in the final preparation is to produceasperities (controlled roughness) on the surface of the copperwhich act as sites for the initiation of corrosion reactions.9. Sampling9.1 Obtain a sample from
35、 a point in the LPG system thatwill give a representative sample of the volume being tested,such as from a dynamic flowing stream or from a well mixedcontainer, as appropriate. Preferably, collect the sample di-rectly into the corrosion test cylinder (6.1) after it has beenprepared for testing (10.1
36、). Pay particular attention to safetyand warning notes in Practices D1265 and D3700.9.2 Alternatively, collect a sample in accordance with Prac-tices D1265 and D3700.9.2.1 If a sample is first collected in a sampling cylinder,ensure that the interior surfaces are inert and will not react withcorrosi
37、ve species. Sampling cylinders with protective (inert)internal coatings or surface treatments (such as fused glass)may be used.NOTE 3Some internal coatings are porous and can adsorb or releasecontaminants that can affect test results.Also, fresh steel surfaces can reactwith some corrosive sulfur spe
38、cies and potentially remove them, whichcould result in a “false pass” in the copper strip corrosion test.9.3 The time between when the sample is collected andwhen the test is begun should be held to a minimum (preferablyonly a few minutes) (see Note 4).9.4 In case of dispute, a sample shall be colle
39、cted directlyinto a corrosion test cylinder.10. Procedure10.1 With Valve B (Fig. 1), open, place approximately 1 mLof distilled water into a clean test cylinder and swirl to moistenthe walls; allow the remainder to drain from the cylinder, insertthe freshly polished copper strip suspended from the h
40、ook onthe dip tube making sure that the bottom of the strip is at least6.4 mm (14 in.) from the bottom of the cylinder whenassembled.After assembly of the apparatus, close both Valve A(Fig. 1), on closure assembly with outage tube, and Valve B.10.2 Holding the test cylinder upright so as not to wet
41、thecopper strip with water, attach the sample source to the testcylinder Valve A (Fig. 1) by means of a short length of flexibleinert hose that has been purged with the sample. Admit somesample to the cylinder by opening the valve at the samplesource and then Valve A.10.3 Close Valve A without disco
42、nnecting the test cylinderfrom the sample source. Invert the test cylinder and open ValveB to purge the air from the test cylinder. Return the test cylinderto the upright position and drain any residual liquid through theopen Valve B. Close Valve B with the test cylinder now in itsupright position,
43、open Valve A and fill the test cylinder with thesample. When the test cylinder is full, close Valve A, the valveat the sample source, and disconnect the tubing.10.3.1 (WarningProvide a safe means for the disposal ofvapors and liquids during this and subsequent procedures.)10.4 As soon as the flexibl
44、e inert hose is disconnected, andwith the cylinder in its upright position, open Valve A slightlyso that all liquid above the end of the outage tube will beremoved from the test cylinder. When vapor first emerges fromValve A, close Valve A.10.5 With minimal delay, and as soon as practical afterfilli
45、ng and venting (described in 10.4) the test cylinder (seeNote 4), immerse the test cylinder in the water bath maintainedat 37.8 6 0.5C (100 6 1F). Allow the test cylinder to remainin the bath for 1 h 6 5 min.NOTE 4Any delay between preparing the test cylinder, collecting thesample, and immersing the
46、 test cylinder in the water bath gives the copperstrip more time in the sample, and thus more time to potentially developincreased discoloration if corrosive species are present in the sample.10.6 At the end of the test period remove the cylinder fromthe bath and, holding the cylinder in a vertical
47、position, openthe bottom valve to a suitable disposal unit (10.3.1) until all ofthe liquid and most of the vapor is discharged.10.7 When only a slight pressure remains in the cylinder,disassemble immediately and compare at once the copper stripthat has been exposed to the liquefied petroleum gases w
48、ith theASTM Copper Strip Corrosion Standard (ADJD0130).10.8 Handling only with stainless steel forceps, compare theexposed strip with the ASTM Copper Strip Corrosion Standard(ADJD0130). See Section 11 for further guidance and clarifi-cation. Hold both the test strip and the standard in such amanner
49、that light reflected from them at an angle of approxi-mately 45 will be observed. In handling the test strip duringthe inspection and comparison, the danger of marking orstaining can be avoided if it is inserted in a flat test tube whichis then stoppered with absorbent cotton.10.9 If the copper strip contacts the water-moistened wallsof the cylinder, or water droplets are splashed onto the copperstrip during sample filling, this can lead to isolated spots on thecopper strip that are typically circular in nature or found alongthe edges of the s
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