1、Designation: D1838 16Standard 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 revis
2、ion. 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 copp
3、er.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.1.2.1 ExceptionThe values given in parentheses are forinformation only.1.3 This standard does not purport to address all of
4、 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. For specificwarning statements, see 7.1, 10.3.1, and Annex A1.2. R
5、eferenced Documents2.1 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:ADJD013
6、0, ASTM Copper 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 expose
7、d at a temperature of 37.8 C(100 F) 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 assura
8、nce that difficul-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 remo
9、vable top closure 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 (see6.1.1). The whole assembly, including the corrosion testcylinder, shall be cons
10、tructed to withstand a minimum hydro-static test pressure of 6900 kPa (1000 psig). No leak shall bediscernible when tested at 3450 kPa (500 psig) with gas.6.1.1 Swivel connections with an adapter to fit a 6.4 mm(14 in.) pipe may be used.6.1.2 The assembly shall be tested for compliance with theminim
11、um pressure rating 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.6.1.3 The assembly shall be verified for gas tig
12、htness byleak 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.6.1.4 Note the presence and length (about 60 mm) of theoutage tube shown in Fig. 1, to provide adequate ull
13、age forsafety. 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, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee
14、D02.H0 on Liquefied Petroleum Gas.Current edition approved June 1, 2016. Published June 2016. Originallyapproved in 1961. Last previous edition approved in 2014 as D1838 14. DOI:10.1520/D1838-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、serviceastm.org. For Annual 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 Internation
16、al, 100 Barr Harbor Drive, PO 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 C 60.5 C (100 F 6 1 F). Incorporate suitab
17、le supports to holdthe test cylinder in an upright position. Make the bath deepenough so that the entire cylinder and valves will be coveredduring the test.6.3 Temperature Sensing Device (TSD)Capable of moni-toring the desired test temperature in the bath to within anaccuracy of 60.5 C (1 F) or bett
18、er.6.4 Strip Polishing Vise, to hold 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(122 F). 2,
19、2,4-trimethylpentane (isooctane) of minimum 99.75 % purity is thereferee solvent and should be used in case of dispute.(WarningExtremely flammable, see Annex A1.)7.2 Copper Strip SpecificationUse strips that are 12.5 mm6 2mm(12 in.) wide, 1.5 mm to 3.2 mm (116 to18 in.) thick,and cut 75 mm 6 5 mm (3
20、 in.) long from smooth-surfaced,hard-temper, cold-finished copper of 99.9+ % purity; electricalbus bar stock is generally suitable. Drill a 3.2 mm (18 in.) holeapproximately 3.2 mm (18 in.) from one end in the center of thestrip. The strips may be used repeatedly but shall be discardedwhen the strip
21、s surface shows pitting or deep scratches thatcannot be removed by the specified polishing procedure, orwhen the surface becomes deformed, or the dimensions for thecopper strip fall outside the specified limits.7.3 Surface Preparation/Polishing Materials00 grade orfiner steel wool; silicon carbide g
22、rit 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. Acommercial grade is suitable, but pharmaceutic
23、al 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 Surface PreparationRemove all surface blemishesfr
24、om 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. Finish with 65 m grade (220-grit CAMI-grade orP220
25、 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 wash solvent from which it can be withdrawn imme-
26、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 silicon carbide paper may be placed ona flat
27、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 surface of the strip may be prepared by use of motor
28、-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 first the ends and then the sides with the 105 m(1
29、20-grit to 150-grit CAMI-grade or P120 to P150 FEPA-grade) silicon carbide grains picked up with a pad of absorbentcotton moistened with wash solvent, making sure that thesurface is protected from coming in contact with the fingers,such as by using ashless filter paper. Wipe vigorously withfresh pad
30、s of absorbent cotton and subsequently handle withouttouching the surface of the strip with the fingers. Paddedforceps (to prevent the scratching of the surface) have beenfound suitable to use. Secure the copper strip in a vise orsuitable holder and polish the main surfaces with silicon-carbide grai
31、ns on absorbent cotton. Do not polish in a circularMetric Equivalentsin. mm in. mm18 3.2 3 7614 6.4 6 152112 38.1FIG. 1 Copper Strip Corrosion Test CylinderD1838 162motion. Rub in the direction of the long axis of the strip,carrying the stroke beyond the end of the strip before reversingthe directio
32、n. Clean all metal dust from the strip by rubbingvigorously 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 Fig. 1).8.2.1 It is important to polish the wh
33、ole 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 order of preparation withthe correctly sized s
34、ilicon 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-grade) paper used in thesurface preparation stag
35、e. 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 a point in the LPG system thatwill give a re
36、presentative 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). Pay particular attention to safetyand warn
37、ing 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 withcorrosive species. Sampling cylinders with protectiv
38、e (inert)internal coatings or surface treatments (such as fused glass)may be used.NOTE 2Some internal coatings are porous and can adsorb or releasecontaminants that can affect test results.Also, fresh steel surfaces can reactwith some corrosive sulfur species and potentially remove them, whichcould
39、result in a “false pass” in the copper strip corrosion test.9.3 Flushing a prepared (wetted) test cylinder with LPG asis the practice at a flowthrough sampling station can invalidatethe test by drying the cylinder walls. While a flow-throughsampling station can help ensure that a representative samp
40、le iscollected, care shall be taken that the procedure for collectinga sample for this test method is followed to remove air but notflow liquid LPG through the cylinder excessively which coulddry the wetted surfaces (10.3).9.4 The time between when the sample is collected andwhen the test is begun s
41、hould be held to a minimum (preferablyonly a few minutes) (see Note 3).9.5 In case of dispute, a sample shall be collected 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 moistent
42、he walls; allow the remainder to drain from the cylinder, insertthe freshly polished copper strip suspended from the hook 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
43、 A(Fig. 1), on closure assembly with outage tube, and Valve B.10.2 Prior to collecting a test sample, air shall be purgedfrom the test cylinder with the sample to be measured in amanner that does not dry the cylinder walls.10.2.1 Holding the test cylinder upright so as not to wet thecopper strip wit
44、h 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.10.2.2 Close Valve A without disconnecting the test
45、 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.10.3 Hold the test cylinder in its upright position whilesampling. W
46、ith Valve B closed, open Valve A and fill the testcylinder with the sample. When the test cylinder is full, closeValve A, the valve at the sample source, and disconnect thetubing.10.3.1 (WarningProvide a safe means for the disposal ofvapors and liquids during this and subsequent procedures.)10.4 As
47、soon as the flexible 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 p
48、ractical afterfilling and venting (described in 10.4) the test cylinder (seeNote 3), immerse the test cylinder in the water bath maintainedat 37.8 C 6 0.5 C (100 F 6 1 F). Allow the test cylinder toremain in the bath for 1 h 6 5 min.NOTE 3Any delay between preparing the test cylinder, collecting the
49、sample, and immersing the 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 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
