NO345371B1 - A spacing device and method of using same - Google Patents

Description

ASPACINGDEVICEANDMETHODOFUSINGSAME

Thepresentinventionisrelatedtoaspacingdevice.Moreparticularly,theinventionisrelatedtoaspacingdeviceforkeepingadistancebetweenanaperturedsheetforsupportinganinsulation,andanobject.

Inforexampleaprocessplant,itisfortechnical,economicorenvironmentalreasonssometimesnecessarytoinsulatepipelinesandrelatedequipmentsuchasvalvesandpumps,fromthesurroundingenvironment.Athermalinsulationismostcommon,butaneedforinsulationmayalsobeduetosound.Athermalinsulationwillbediscussedinthisdocument.

Therearetwomainpurposesforthermalinsulationofpipelineandrelatedequipment.

Onepurposeofthermalinsulationofapipelineistoreduceaheatexchangebetweena fluidflowingthroughthepipelineandthesurroundingenvironment.

Anotherpurposeofthermalinsulationistoprotectthepipelineand/orfluidflowingthrough thepipeline,againstheatthatmayoccurforexampleintheeventofafire.

Dependingonatemperaturedifferencebetweenanoutsideoftheinsulationfacingasurroundingenvironment,andaninsideoftheinsulationfacingabodysuchasapipe,anda relativehumidityoftheairwithintheinsulation,condensationmayoccur.Suchcondensationmayrepresentchallengeswithrespecttoreducedeffectofthethermalinsulationand increasedweight.However,themostseriousconsequenceofsuchcondensation,isincreasedriskofcorrosionoftheinsulatedequipment.SuchcorrosionisknownasCUI (CorrosionUnderInsulation)andrepresentsasafetyriskinadditiontoincreasedmaintenancecosts.

Toreducetheproblemofcondensationininsulationmaterialsurroundingforexampleapipeline,itiscommonpracticetoprovideaspacebetweentheinsulationmaterialand

anoutersurfaceoftheinsulatedobject,suchasapipeline.

Toprovidethespaceseveraltypesofspacingdevicesexistinthemarked.

Onesuchtypeofspacingdeviceisundulatingorcorrugatedmetalribbonssurrounding thepipeandbeingspacedapartinanaxialdirectionofthepipeline.Theribbonsareconfiguredforsupportingametalsheetprovidingasupportfortheinsulationmaterial.The corrugatedmetalribbonisappliedaroundthepipeandattachedtoitselfbymeanspop rivetssothattheribbonisformedasanendlessloop.Theskilledpersonwillappreciate thatapipelineinoperationmaybesubjecttovibrations.Suchvibrationsmaycauserubbinganddamageofthesurfaceofthepipelineabuttingridges/valleysoftheundulating metalribbonanddamagethepipeline.However,suchrubbingmaybeavoidedbyarranginganisolatingmaterial,forexamplearubbersheetbetweenthesurfaceofthepipeline andtheundulatingmetalribbon.Mountingsuchrubbersheetsiscumbersomeandtime consuming.Afurtherdisadvantageofprovidingsucharubbersheetisthatmoisturemay betrappedbetweentherubbersheetandthesurfaceofthepipeline.

Anothertypeofspacingdeviceisasplitringmadeofaplasticmaterial.Thesplitringisprovidedwithapluralityofinwardsprotrudingribsextendinginparallelwithalongitudinal axisofthepipeline.Inuse,apluralityofsplitringsarespacedapartinanaxialdirectionof thepipeline.Thesplitringsareconfiguredforsupportingametalsheetprovidingasupportfortheinsulationmaterial.Asplitringofplasticisnotencumberedwiththerubbingdamagesofthesurfaceofthepipelineasmaybethecaseforthemetalribbonmentionedlimitedabove.However,asplitringmayonlybeusedforarangeofthepipeline. Further,dependingonwhichtypeofpolymertheplasticismadefrom,asplitringofacertaintypeofplasticmaybeusedforalimitedtemperaturerange.Thus,arangeofdiameterswhereineachrangeisavailableinseveraltypesofplastic,mayberequired.

Stillanothertypeofspacingdeviceisaribbonmadefromrubber,whereintheribbonisprovidedwithundulatingportionsand“hingetype”lockingmeansconfiguredforprovidingandendlessribbonafterbeingmountedaroundapipeline.Inuse,apluralityofribbonsarespacedapartinanaxialdirectionofthepipeline.Theribbonsareconfiguredforsupportingametalsheetprovidingasupportfortheinsulationmaterial.Althoughhavingcertainflexibilitywithregardtodimensionofthepipeline,itmayinbonmanycasesbenecessarytoadaptto

Aspacingdevicebeingindependentofdiameterofthepipelineareso-calledspacer knobsconfiguredforbeingconnectedtoaperforatedsheet.Forthistypeofspacing

deviceapluralityofspacerknobsarearrangedcircumferentiallyandaxiallyalongthe pipelinetokeepthesheetandthustheinsulationsubstantiallyequidistantlyfromthepipeline.Thesheetservesasasupportfortheinsulationmaterialandistypicallymadeof metal.Thespacerknobsaretypicallymadefrompolytetrafluoroethylene(PTFE),suchas Teflon®.Eachknobissecuredtothemetalsheetbymeansofascrewscrewedthrough theknobandintoaperforationinthemetalsheet.Asaminimum,threeknobsaresubstantiallyequidistantlyarrangedaroundaperipheryofthepipelineatpredeterminedintervals,forexamplethreeateach300mmalongthepipeline,whichresultsinaneedfor 1000spacerknobsforeach100mpipeline.Assemblingofsuchpriorartspacerknobsis arelativelytimeconsumingandcumbersomeassemblyprocessinthattheknobmustbe heldinplacebyonehandwhilethescrewisalignedwiththeperforationandscrewed throughtheknobandintotheperforationinthemetalsheet.Experienceshowsthatitis easytoloseascreworaspacerknobwhiletheassemblyprocessisinprogress.

PublicationGB2539595disclosesaninsulationassemblycomprisingi.a.asupportarrangementthatprovidessupportforashell.Thesupportarrangementisintheformofametalringprovidedwithinwardlyextendingelongatemembersabuttingagainstasurfaceofpipesothatthemetalringiscoaxialwiththepipe.Bymeansofthemetalring,theshelliskeptatadistancefrominsulationmaterialabuttingagainstthepipesuchthatthereisavoidbetweentheinsulationmaterialandtheshell.

PublicationUS2002/0083993disclosesamethodforinhibitingexternalcorrosiononaninsulatedpipelineincludingpipeinsulationpositionedoutsideandaroundthepipeanda coatingmaterialaroundtheinsulationbypositioningapluralityofconcentratedchargesof alkalinematerialintheinsulationmaterial.

Theinventionhasforitsobjecttoremedyortoreduceatleastoneofthedrawbacksofthepriorart,oratleastprovideausefulalternativetopriorart.

Theobjectisachievedthroughfeatures,whicharespecifiedinthedescriptionbelowand intheclaimsthatfollow.

Inafirstaspectoftheinvention,thereisprovidedaspacingdeviceforkeepingadistancebetweenanaperturesheetforsupportinganinsulation,andanobject,thespacingdevicecomprises:abodyhavingafirstendportionandasecondendportion;andanengagementelementprotrudingfromthesecondendportionofthebody.Theengagementelementisfixedwithrespecttothebodyandaportionoftheengagementelementisconfiguredforpenetratingthroughanapertureinthesheetforsecuringthespacingdeviceto

thesheet.

Bythetermfixedismantthattheengagementelementformsanintegralpartwiththebodydispreventedfromrotatingwithrespecttothebodyofthespacingdevice.

Theobjectmaytypicallybeapipeorpipelineandpipeline-relateditemssuchasforexampleavalveformingpartofapipeline.

Oneeffectofprovidinganengagementelementthatisfixedwithrespecttothebodyand configuredforengagingtheaperturessothatthespacingdeviceinpositionofuseis securedtothesheet,isthatanoperatorcansecurethespacingdevicetothesheetby onehandwithoutanytool.Sincenotool,suchasanelectricaldrillorscrewdriverisrequiredwhensecuringthespacingdevicetothesheet,theoperationmaytakeplaceinso-calledEX-zones(areassubjecttogasexplosionorflammabledust).

Inoneembodiment,theengagementelementmaybeprovidedwithatleastoneresilient lockingdeviceconfiguredforallowingaxialmovementoftheengagementelementina firstdirectionthroughtheapertureofthesheetbutpreventedfrommovementinasecond directionoppositesaidfirstdirection.Inoneembodiment,theresilientlockingdeviceisby meansofatleastonelipconfiguredforsnappingthroughtheapertureofthesheet.Aresilientlockingdeviceallowsthespacingdevicetobesecuredtothesheetsimplybypushingtheengagementelementthroughtheaperture,i.e.applyinganaxialforcetowardsthe bodyofthespacingdevice,untilthesecondendportionofthespacingdeviceabutsan innersurfaceportionofthesheet.Inordertopreventtheengagementelementfrommovingintheseconddirection,thelipmustbecapableofabuttinganoutersurfaceofthe sheetafterhavingpassedtheapertureofthesheet.

Inanotherembodiment, theengagementelementprovidedwithathreadedportionconfiguredforengagingaperipheryportionofanapertureinthesheet.

Instillanotherembodiment,theengagementelementofthespacingdevicecomprisesa helicalportionforengaginganapertureofthesheet.Thishastheeffectthatacross-

sectionoftheengagementelementmaybesmallerthantheaperture,aswillbeexplainedinmoredetailbelow.

Atleastfortheabove-mentionedembodimentswhereintheengagementelementmaybeprovidedwithathreadedportionorahelicalportion,theengagementelementmaybemadeofamaterialbeingdifferentfromthematerialofthebody.Inoneembodiment,theengagementelementmaybemadeofamaterialbeinglessflexiblethanamaterialofthebody.Inoneembodiment,theengagementelementismadefromametal,whilethebodyispreferablymadefromanon-aggressivematerialsuchasforexamplesiliconerubber. Bytheterm“non-aggressivematerial”ismantamaterialthatwillnotrubthesurfaceofthebodyforexampleiftheobjectvibrates.

Inasecondaspectoftheinvention,thereisprovidedamethodforprovidingaspacebetweenanobjectandasheetbymeansofthespacingdeviceaccordingtothefirstaspectoftheinvention.Themethodcomprisesthestepsof: -a)aligningtheengagementelementofthespacingdevicewithanapertureprovidedin thesheet; -b)urgingaportionoftheengagementelementthroughtheaperturebyapplyingaforce tothebodyofthespacingdevicetosecurethespacingdevicetothesheet;and -c)repeatingstepsa)andb)toprovideapluralityofspaced-apartspacingdevicesprotrudingfromasurfaceofthesheet;and -d)movingthesheetwiththeprotrudingspacingdevicestowardstheobjectssothatthefirstendportionofthespacingdevicesabutasurfaceoftheobject.

The aperture for receiving the engagement element of the spacing device are preferably premade.

Instepb)theforceappliedtothebodyisatorqueand/oracompressiveforce.

Inthirdaspectoftheinventionthereisprovidedaninsulatedobjectcomprisingthespacingdeviceaccordingtoanyembodimentsofthefirstaspectoftheinvention.Theobjectmaytypicallybeapipelinewhereinthesheetiskeptsubstantiallyequidistantlyfrom anoutersurfaceofthepipelinebypluralityofspacingdevicesabutting,inapositionofuse,asurfaceofthepipeline.Theinsulatingmaterialabutsoutsideofthesheet.Thus, thesheetandthespacingdevicekeeptheinsulationmaterialfromanoutersurfaceofthepipeline-apart

Itisfurtherconceivabletoattachthespacingdevicetothesheetbymeansofanadhe-

sive.Forexample,adouble-sidedtapecouldprovideabindingbetweenthetopportionof thespacingdeviceandthesheet.Inoneembodiment,thespacingdeviceisprovidedwithboththeconnectionelementandanadhesive.

Theinventionisdefinedbytheindependentpatentclaims.Thedependentclaimsdefineadvantageousembodimentsoftheinvention.

In thefollowingaredescribedexamplesofpreferredembodimentsillustratedintheaccompanyingdrawings,wherein:

Fig.1 showsspacingdevicesaccordingtotheinventionprovidedinapositionofusebetweenpipeandanaperturedsheet;

Fig.2 showsradialviewoffig.1seenfromtheleft;

Fig.3a–3b showinlargerscaleafirstembodimentofaspacingdeviceaccordingtothepresentinvention;

Fig.4a–4b showinlargerscaleasecondembodimentofaspacingdeviceaccordingtothepresentinvention;and

Fig.5a–5c show in larger scale a third body and spacing device according to the present invention.

Anypositionalspecificationsusedhereinrefertothepositionsshowninthefigures.

In the figures, the same or corresponding elements are indicated by the same reference numerals and letters.

Apersonskilledinheartwillunderstandthatthefiguresarejustprincipledrawings.

In the figures, reference numeral 1 denotes a spacing device according to the present invention.

Thespacingdevice,hereshownasaknob1comprisesabody3havingafirstendportion5andasecondendportion7.Theknob1furthercomprisesanengagementelement10protrudingfromthesecondendportion7ofthebody3.

The engagement element 10 is fixed with respect to the body 3, meaning that the engagement element 10 forms an integral part with the body 3, and that the engagement element 10 is prevented from rotating with respect to the body of the spacing device or

knob1.

Figures1and2showtheknob1inatypicalpositionofuse.Apluralityofknobs1(four showninfig.2)aredistributedcircumferentiallyaroundanoutersurfaceofanobject,hereshownapipeP.Inwhatfollows,thepipePwillalsobenotedpipelineP.

Apurposeoftheknob1istoprovideaspacebetweenthepipePandasheetSconfiguredforprovidingasupportingbaseforaninsulationmaterialIMforinsulatingthepipeP. Apurposeofthespaceisinteraliatoreducetheproblemofcondensationintheinsulationmaterial,andtoavoidanywetininsulationtobeincontactwithasurfaceofthepipeP.AtcertainintervalsalonglongitudinalaxisofthepipeP,forexampleeach300mm,anewsetofminimumthreeknobs1maintainssheetSspacedapartfromtheoutersurfaceofthepipeP.ThepurposeoftheinsulationmaterialIMistoprovideathermalinsulation,a fireprotectioninsulationand/orasoundinsulationasdinheartbetappreciatedbyaperson.

Eachknob1issecuredtothesheetSbyurgingtheengagementelement10throughadesiredapertureSAprovidedinthesheetS.Intheembodyshowninfig.1,thesheetSisprovidedwithapluralityofpremadeapertures,i.e.thesheetisanaperturedorperforatedsheetS.SuchanaperturedsheetSistypicallymadefromametal.

Itshouldbenotedthattheknobs1accordingtotheinvention,inthesamewayasapriorartknob/screw-arrangementasdiscussedabove,aresecuredtothesheetSpriortofoldingthesheetSwithknobs1attachedthereto,aroundthepipelineP.

Two forman“endless”sheetSsurroundingthepipelineP,theendportionsofthesheetwhicharesubstantiallyinparallelwithalongitudinalaxisofthepipelineP,aretypicallymadeoverlappingandsecuredtoeachotherbyfasteningmeanssuchasforexamplepoprivets(notshown).

Figures 3a–5c show various embodiments of the engagement element 10 of the knob 1.

Infigures3aand3btheengagementelementsintheformofapin10providedwithaliporflange12extendingradiallyoutwardsfromanendportionofthepin10.

Adiameteroftheflange12islarger thandiameteroftheapertureSA(seefig.1)inthesheetS,butstillsufficientlysmalandsoresilienttoallowanouterportionoftheflange12tobenddownwards(towardsthesecondendportion7ofthebody3)whenurgedthroughtheapertureSA,andtorecaptureitsoriginaldisk-shapedformwhenhaving

passedthroughtheapertureSA.Adiameterofthepin10maybesmaller thandiameteroftheapertureSA,i.e.thepin10doesnothavetofullymatewiththeperipheryofthe apertureSA.

WhenhavingpassedinafirstdirectionthroughtheapertureSA,theknob1ispreventedfrommovementinaseconddirectionoppositesaidfirstdirectionduetotheflange12 abuttingaperipheryoftheapertureSAonanoutersurfaceofthesheetS.Theengagementelement10showninfigures3aand3bmaybeberegardedasasnap-inlockingdevice activatedbyapplyinganaxialforcetowardsthefirstendportion5ofthebody3.Theforcemaytypicallybeappliedbyathumbofanoperator.

Theembodimentshowninfigures4aand4bsimilaritieswiththeembodimentshown infigures3aand3binthattheengagementelement10isintheformofapin10.However,insteadoftheliporflange12asshowninfigures3aand3b,theengagementelement10showninfigures4aand4bisprovidedwithathreadedportion14.Thethreadedportion14isconfiguredforengagingaperipheryportionoftheapertureSAofthesheetS. Thus, the diameter of engagement element 10 must be mating with the diameter of the aperture SA.

Theengagementelement10showninfigures4aand4bmayberegardasascrew-in lockingdeviceactivatedbyapplyingatorqueonthebody3.Theforcemaytypicallybeappliedbytwofingersofanoperator.

Theembodimentshowninfigures5a–5chassimilaritieswiththeembodimentshowninfigures4aand4binthattheengagementelement10issecuredtothesheetSbyapplyingatorqueonthebody3.However,insteadofbeingathreadedpin,theengagementelement10showninfigures5a-5chasaspiral-form.

Afurtheradvantageoftheembodimentshowninfigures5a–5cinviewoftheembodimentshowninfigures4aand4binparticular,isthatadiameterofarodformedintothe spiralisindependentofadiameteroftheapertureSAofthesheetStowhichtheknob1 istobeconnected,aslongastherodpassesthroughtheapertureSA.Thus,theknob1 havinganengagementelement10asshowninfigures5a–5cmaybeusedforsheets havingaperturesofdifferentdiametersordifferentdesigns.WhenscrewedintotheapertureSAofasheetS,aperipheryportionoftheapertureSAofthesheetSwillbe “wedged”or“jammed”betweenaninclinedportionoftheengagementelement10facing thesecondendportion7ofthebody3,andthesecondendportion7itself.

Theengagementelement10showninfigures5a–5cmaytypicallybemadefromahelicalspringmadefromametalandpartlysubmergedintoasuitablebodymaterialsuchasforexamplearubbermaterial,aplasticmaterialorothernon-aggressivecastmaterials. Fig.5indicatesbydottedlinesanengagementelement10partlysubmergedinthebody3oftheknob1.

Similarly, theengagementelement10showninfigures4aand4bmayinoneembodybemadefromametalandpartlysubmergedintoasuitablebodymaterialsuchasforexamplearubbermaterial,aplasticmaterialorothernon-aggressivecastmaterials.

Thus,thematerialofthebody3oftheknob1maybemadefromamaterialhavingdifferentmaterialcharacteristicsfromthatoftheengagementelement10.

Intheembodimentsshown,aportionofthebody3whichisconfiguredforabuttingforexampleapipelineP,ishemispherical.Onepurposeofsuchaformistorereduceacontactareabetweenthespacingdeviceorknob1andsurfaceofthepipelineP.Areduced contactareawillrepresentareducedriskofentrappinganymoistureintheinterfacebetweentheknob1andthepipelineP.

Fromtheabovetheskilledpersonwillunderstandthatthespacingdevice1accordingtotheinventionisa“one-piece”spacingdevice1thatissecurabletoasheetSforuseasfor exampleaninsulationsupportS,withouttheneedofanytoolapartformahandofanoperator.

Itshouldbenotedthattheabove-mentionedembodimentsillustrateratherthanlimitthe invention,andthatthoseskilledintheartwillbeabletodesignmanyalternativeembodimentswithoutdepartingfromthescopeoftheappendedclaims.Intheclaims,anyreferencesignsplacedbetweenparenthesesshallnotbeconstruedaslimitingtheclaim.Use oftheverb"comprise"anditsconjugationsdoesnotexcludethepresenceofelementsor stepsotherthanthosestatedinaclaim.Thearticle"a"or"an"precedinganelementdoes notexcludethepresenceofapluralityofsuchelements.

Claims (9)

C l a i m s 1. Aspacingdevice(1)forkeepingadistancebetweenanaperturedsheet(S)forsupportinganinsulation,andanobject(P),thespacingdevice(1)comprising: -abody(3)havingafirstendportion(5)andasecondendportion(7); -anengagementelement(10)protrudingfromthesecondendportion(7)ofthe body(3), c h a r a c t e r i s e d i n thatengagementelement(10)is fixedwithrespecttothebody(3)andportionoftheengagementelementis configuredforpenetratingthroughanaperture(SA)inthesheet(S)forsecuringthespacingdevicetothesheet(S). 2. Thespacingdevice(1)accordingtoclaim1,whereintheengagementelement(10)isprovidedwithatleastoneresilientlockingdevice(12)configuredforallowingaxialmovementoftheengagementelement(10)infirstdirectionthrough theaperture(SA)ofthesheet(S)butpreventedfrommovementininaseconddirectionoppositethesaidfirstdirection. 3. Thespacingdevice(1)accordingtoclaim1,whereintheengagementelement(10)isprovidedwithathreadedportion(14)configuredforengagingaperipheryportionofsaidaaperture(SA). 4. Thespacingdevice(1)accordingtoclaim1,whereintheengagementelement(10)comprisesahelicalportionforengagingsaidaperture(SA). 5. Thespacingdevice(1)accordingtoclaim3or4,whereintheengagementelement(10)ismadeofamaterialbeingdifferentfromthematerialofthebody(3). 6. Thespacingdevice(1)accordingtoclaim5,whereintheengagementelement (10)ismadeofamaterialbeinglessflexiblethanamaterialofthebody(3). 7. Amethodforprovidingspacebetweenanobject(P)andasheet(S)bymeansofthespacingdevice(1)accordingtoanyoftheprecedingclaims, c h a r -a c t e r i s e d i n thatthemethodcomprises: -a)aligningtheengagementelement(10)ofthespacingdevice(1)withanaperture(SA)providedinthesheet(S); -b)urgingaportionoftheengagementelement(10)throughtheaperture(SA) byapplyingaforcetothebody(3)ofthespacingdevice(1)tosecurethespacingdevice(1)tothesheet(S);and -c)repeatingstepsa)andb)toprovideapluralityofspaced-apartspacingdevices(1)protrudingfromasurfaceofthesheet(S);and - d)movingthesheet(S)withtheprotrudingspacingdevices(1)towardstheobject(P)sothatthefirstendportion(5)ofthespacingdevices(1)aboutasurfaceoftheobject(P). 8. An insulated object (P) comprising the spacing device (1) according to any of the claims 1-6. 9. Theinsulatedobject(P)accordingtoclaim8,whereintheobject(P)isapipeline,andthesheet(S)iskeptsubstantiallyequidistantlyfromanoutersurfaceofthe pipeline(P)bypluralityofspacingdevices(1)abutting,inapositionofuse,asurfaceofthepipeline(P). Patent claims 1. A distance device (1) to keep a distance between a thin plate (S) provided with openings, and arranged to support an insulating agent, and an object (P), where the distance device (1) comprises: - a body (3) having a first end part (5) and a second end part (7); - an engagement element (10) projecting from the other end portion (7) of the body (3), characterized in that the engagement element (10) is fixed with respect to the body (3), and a part of the engagement element is configured to penetrate a opening (SA) in the thin plate (S) to attach the spacer to the thin plate (S). 2. Distance device (1) according to claim 1, where the engaging element (10) is provided with at least one elastic locking device (12) configured to allow axial movement of the engaging element (10) in a first direction through the opening (SA) in the thin plate (S) , but prevented from moving in a second direction opposite to said first direction. 3. Distance device (1) according to claim 1, where the engagement element (10) is provided with a threaded part (14) configured for engagement with a peripheral part of said opening (SA). 4. Distance device (1) according to claim 1, where the engagement element (10) comprises a spiral-shaped part for engagement with said opening (SA). 5. Distance device (1) according to claim 3 or 4, where the engagement element (10) is made of a material that is different from the material of the body (3). 6. Distance device (1) according to claim 5, where the engagement element (10) is made of a material which is less flexible than the material of the body (3). 7. Method for providing a space between an object (P) and a thin plate (S) using the distance device (1) according to any one of the preceding claims, characterized in that the method comprises: - a) aligning the distance device (1) engagement element (10) with an opening (SA) provided in the thin plate (S); - b) driving a part of the engaging element (10) through the opening (SA) by applying a force to the body (3) of the spacer (1) to attach the spacer (1) to the thin plate (S); and - c) repeating steps a) and b) to provide a plurality of spacers (1) spaced apart and projecting from a surface of the thin plate (S); and - d) to move the thin plate (S) with the protruding spacer devices (1) towards the object (P) so that the first end part (5) of the spacer devices (1) rests against a surface of the object (P). 8. Isolated object (P) comprising the distance device (1) according to any one of claims 1-6. 9. Isolated object (P) according to claim 8, where the object (P) is a pipe line, and the thin plate (S) is kept essentially at the same distance from an outer surface of the pipe line (P) by means of a plurality of distance devices (1) which, in a position of use, rests against a surface of the pipeline (P).