NON-DESTRUCTIVE MATERIAL TESTING · DELTA TEST – We do eddy current. DELTA TEST – a name that stands for qualified, non-destructive material testing using the eddy current procedure.

NON-DESTRUCTIVE MATERIAL TESTING

TABLE OF CONTENTS

DELTA TEST – We do eddy current. Page 2-3

What are eddy currents? Page 4-5

DELTA TEST – We give you security.

TUBULAR INSPECTIONS Page 6-15

DELTA TEST - We make surface cracks visible.

SURFACE CRACK INSPECTIONS Page 16-21

DELTA TEST – We will find a solution for your inspection problem.

SPECIALIZED INSPECTIONS Page 22-25

DELTA TEST – We help develop the future.

RESEARCH, DEVELOPMENT, PRODUCTION Page 26-33

Cooperation/Certification Page 34

DELTA TEST- What can we do for you? Page 35

DELTA TEST

TUBULAR

INSPECTIONS

SURFACE

CRACK INSPECTIONS

SPECIALIZED

INSPECTION

RESEARCH, DEVELOPMENT,

PRODUCTION

DELTA TEST

2

EINSATZBEREICHE

DELTA TEST – We do eddy current.DELTA TEST – a name that stands for qualified, non-destructive material testing using the eddy current procedure.

Since its foundation in 1988, DELTA TEST has been carrying out state-of-the-art eddy current test services,according to customer requirements and based on respective norms and standards. We are specialised in all kindsof eddy current tests and provide these around the world. Tests of paramagnetic and ferromagnetic heatexchangers play a significant part in this.

DELTA TEST guarantees short response times from the initial enquiry through to job execution, and furthermoreoptimally short test times with at the same time high quality test results. Our aim is to provide information throughhigh-quality and reliable test results, which will help you to lower your costs for maintenance and repair in thelong-term.

With this reliability and our availability around the clock, we can achieve a relationship of complete trust with ourcustomers. Our national and international success is based on highly motivated, certified and qualified employees andmodern equipment, development achievement and the ability to implement innovative ideas for you and with you.

DELTA TEST provides you with the security you require – fast, straightforward und successful! >>

3

Our comprehensive services in thearea of eddy current inspections areperformed by certified inspectorsdirectly on site as well as in thecompany laboratory. Naturally, ourcustomers can contact us and ourdevelopment department withregard to individual inspectionproblems at any time.

Heat exchanger inspections Mechanized eddy current inspections with crawlers and scanners IRIS inspections Videoscope inspections Tube leak testing Sleeve shaft tests Weldolet and hot surface inspections Flange sealing surface inspections Eddy current inspections of RDB threads and bolts Eddy current inspections in confined spaces via 3-axis manipulator Boiler and furnace tube inspections Surface crack inspections Turbine blade inspections Rolling bearing inspections Brake disc inspections Rail inspection Eddy current array technique

Chemical and

petrochemical plants Refineries Nuclear power plants Conventional power plants Waste incinerators Sugar factories Sea water desalination plants Oil rigs Rail cars/train Aircraft industry Automotive industry Pressure tank industry Tube manufacturers

DELTA TEST

Ferromagnetic tubes Condenser tubes Air-fin cooler tubes High-pressure tubes U-bended tubes Tube-sheet expansion zones Boiler and furnace tubes

Google on the Internet is always hel-

pful for answering such questions. If

eddy current is entered as a search

term, this results in more than

120,000 hits, which is rather a lot

and indicates that eddy current is

fairly well known.

From our everyday lives we knowthat there are materials whichconduct electric current, like forexample cables. These electricallyconductive materials are mostlymetals like copper, brass, iron andsteel. If such materials are broughtinto a magnetic alternating field, themagnetic field penetrates thematerial and causes eddy cur-rents within it. They are called

"eddy" currents because theyusually move on curved lines in theelectrically conductive materials andmove back and forth to the rhythmof the stimulating magnetic alter-nating field. So they do havesomething "eddy" about them,which is why their name reflectstheir behaviour. Now the electriccurrent is essentially nothing elsethan the movement of negativelycharged electrons in the conductivematerial. This means that our eddycurrents are electrons moving backand forth in the material. Comparedto everyday life the material couldbe a large city, with the electronsmoving about like people.

Simplified principle of eddy current testing

Coil

Secon-

dary

field

Primary

field

Measuring

coil

Eddy

currents

5

Professor Dr.-Ing. Dieter Stegemann

What are eddy currents?In non-destructive test methods, eddy current technology increasingly gains in importance. The reason for this isthat it is a test method that is flexible in its application and that its probes, usually coils of copper wire, are veryadaptable and can be produced fairly easily.

Usually, people that move causesomething. Is it the same forelectrons? The answer is: Yes.Their movement, which is a cur-rent – the eddy current -, causes amagnetic alternating field on theirpart, which opposes the stimulatingmagnetic field and weakens it. Thismagnetic alternating field createdby the eddy currents is called sec-ondary field, which occurs as a re-sult of the stimulating magneticfield. The stimulating magnetic al-ternating field is the primary field.The primary magnetic alternatingfield is usually created by coilscarrying alternating current.These ensure that the primary fieldenters the material and stimulatesthe eddy currents. This causes“stimulated” electrons to moveback and forth on curved lines. Thehigher the electrical conductibility ofthe material, the better thefunctioning of the eddy currentgeneration. The eddy currentsthemselves are not passive andcreate a secondary magnetic alter-nating field due to their movement,which weakens the primary field andcan thus be detected outside of thematerial. The secondary field canthus give evidence of the behaviourof the eddy currents on the insideof the material. Large cities have it alittle easier, as traffic and pedestrianmovements can be monitored by

video cameras. But the secondaryfield can also respond quite sen-sitively to disturbances in thematerial and is thus a suitableverification tool.

Why can eddy currents be used for

non-destructive tests?

Eddy currents are electrons movingback and forth on curved lines in thematerial. These electrons can serveas “spies” so to speak, indicatingwhether all is as it should be withinthe material or whether there areany disturbances. For example, sucha disturbance could be a crack in ametal. For the moving electrons thiscould be a big obstacle which couldblock their way, so that they wouldneed to find a different route. Comingback to the comparison with a largecity, this could for example be ablocked road. Now how does suchan obstacle affect the electrons inthe material? The electrons cannotmove across the obstacle, so thereis no eddy current here. This alsomeans that there is no secondarymagnetic field at the site of the ob-stacle, which in turn also means theprimary stimulating field is notweakened. This implies that flaws inan electrically conductive materialcan be detected via the amplitudeof the magnetic alternating field re-sulting from the overlay of stimulat-

ing field and secondary field. If theelectrons are forced to make adetour due to the obstacle, whichrequires additional time, thismeans that – compared to theuninterrupted case – there is atime shift between the primary andthe secondary magnetic field. Thisis called a displacement of phasebetween the two fields. This canalso be measured.

For finding flaws in the material,amplitudes and phases of magneticfield changes caused by the eddycurrents are thus available. Differ-ent flaws in the material obviouslycause different behaviour of theeddy currents and their signals,which makes it possible to differen-tiate between various flaws. Forexample, material losses or wallattenuations due to corrosion providedifferent signal responses than thealready mentioned cracks. For thisreason, the application of materialtests with eddy currents can bequite versatile. The measuringprobes used in eddy currenttechnology normally consist of atransmitting coil for creating thestimulating primary field and a re-ceiving coil for measuring the re-sulting magnetic field. For thisreason, the production of coils isrelatively simple and cost-effective.Electrical voltages and currents in

the frequency range up to a fewmegahertz are used. Usually, theanalogue signals from the probesare transformed to digital signals,so that the eddy current signalscan be analysed quickly and easily.As these are electromagneticsignals, their effect is quick, andhigh test speeds can be achieved.The signals and their processingand analysis enables the creationof fully automatic eddy currenttest systems for online or inlinetesting of work pieces duringproduction.

Source:Der Einsatz von Wirbelströmen für die zerstörungsfreie WerkstoffprüfungDieter Stegemann,em. ord. Professor Dr.-Ing.Fakultät fü�r MaschinenbauLeibniz Universität Hannover

DELTA TEST

DELTA TEST – We give you security.Trust is not enough, control is indispensable!

When its about security and the flawless operation of your heat exchanger tubes, this could be your motto! With targeted utilisation of eddy current testing, DELTA TEST can help you to always be on the safe side andto avoid unplanned downtimes for example.

Prevent all risks with regular inspections and instead gain complete security! >>

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Frequently, heat exchanger tubes

from different material are affected

by corrosion.

This can result in leakages, which inturn bear the risk of consequentialdamages like a longer search forleakages and decreased perfor-mance of the system. The worstcase scenario is environmentaldamage. The significant financialdamage for the company mustalso be considered.

With the eddy current inspectionprocedures used by DELTA TEST, ourcustomers have a problem-orienteddetection of tube damages at theirdisposal. By using the most recentcomputer technology, our compe-tent technicians and engineerscreate an overview of the actualsituation of each heat exchangersystem, and depending on the re-spective type of damage, the cus-tomer can take the required actionsfor repair. Furthermore, frequentlyinspections enable tracking of dam-ages, which confirm successfullyintroduced protective measures aswell as allow an estimation of thelife cycle.

Heat exchanger tubes are extreme-

ly important components, which

can be found in all kinds of indus-

trial systems like power or chemical

plants. Smooth and faultless func-tioning of these components is vitallyimportant for whole system parts.DELTA TEST gives its customerssecurity! Through frequently inspec-tions of heat exchangers, unplanneddowntimes (breakdowns) can thus bereduced by 95%, and completely newtube systems of heat exchangers aswell as storage of replacementtubes can be decreased to a mini-mum. Adding to this is the risk lim-itation in the area of environment aswell as a further prevention of finan-cial damages due to productiondowntimes.

The probability of detection (POD)when using our test system is morethan 80%, which compared to othertest methods like IRIS, RFT or MFLrepresents significantly higherreliability.

Furthermore, extended inspectionsystem modules like automatedsignal analysis in the backgroundand a precise position detectionsystem ensure maximum security. Inaddition, we offer our customersspecific expertise when testing

ferromagnetic heat exchanger tubes(e.g. carbon steel, duplex, monel).Testing usually takes place with thetest object installed, but it can alsobe used for lose tubes. Due to theimmediate signal analysis, testresults are immediately available toour customers. This means thatpossible additional repair measurescan be performed immediately andwithout loss of time.

Heat exchanger tubes

TUBULAR

INSPECTIONS

Straight tube heat exchanger U tube heat exchanger

Eddy current inspections above the tube length of a heat exchanger

Rear Test side

Heat exchanger

Conventional eddy current probe

Applications

of tubular inspections

Ferromagnetic tubes

Condenser tubes

Air-fin cooler tubes

High-pressure tubes

U-bended tubes

Tube-sheet expansion zones

Boiler and furnace tubes

8

Testing of ferromagnetic tubes

Steel and ferrous material as well as

nickel-containing alloys are ferro-

magnetic within the technically

relevant temperature range, i.e.

below the Curie temperature.

This means that after switching offan exterior field (magnet), a solidobject keeps exhibiting measurablemagnetic characteristics, a residualmagnetization or remanence. Thiscontinuation of an effect after dis-continuation of the cause is calledhysteresis. Hysteretic properties offerromagnetic materials hampereddy current testing severely. DELTATEST has the required know how forthis.

The magnetization of a body de-pends on the exterior field thatmagnetizes it. There is a differencein the behaviour of paramagneticmaterials, like zinc and aluminium,and ferromagnetic materials, likeiron, cobalt and nickel, with regardto their permeability and their re-sponse after magnetization isswitched off. The permeability offerromagnetic materials is a deci-sive interference factor in tubetesting, which must initially beminimized as much as possible.In paramagnetism, the molecularmagnets are aligned by an exteriormagnetic field so that theiralignment matches the exteriorstimulating magnetic field. If theparamagnetic material is located ina coil, the molecular magnets arerotated in direction of the exteriorfield. Once the exterior field isswitched off, the molecular mag-nets return to their originalalignment and the solid object doesnot exhibit any residual magneticproperties on the outside.

For ferromagnetic materials, analmost complete alignment of themolecular magnets also takes place,but this is partly irreversible. Thisresidual magnetization can only beremoved by applying an exterioropposing field with a material-dependent field strength, the co-ercive field strength. The cycle ofmagnetization, remanence, coercivefield strength and back-magneti-zation is described in the hysteresisgraph above.

DELTA TEST has developed a proce-dure with which eddy current testingcan be successfully performed evenfor ferromagnetic materials like steeltubes. This is possible by applyingpremagnetization procedures. Forthis, specifically developed probesare used, which reduce the ferro-magnetic properties – the perme-ability – of the material to a con-stant level which is a low as possible.The aim is to render the material-dependent relative permeability μrto a value near 1. This causes theeddy currents in the material tobehave similar to the behaviour inparamagnetic materials. This enablesan evaluation of the eddy currentsignals by particularly experiencedand trained experts. Furthermore,based on technical auxiliary meanslike automatic locators, special eddycurrent visualisation software andintelligent automatic signal analysisalgorithms precise test results canbe achieved, which are almost asgood as conventional eddy currenttest methods for paramagnetictubes.

Coercive field strengthSaturating field strengthSaturation flux densityRemanence

Initial magnetisation curve

Direction of the

exterior field during the initialmagnetisationcurveHysteresis curve

9

TUBULAR

INSPECTIONS

Comparison of methods for testing ferromagnetic heat exchanger tubes

Partial Saturated

Eddy Current - PSEC

Eddy current test procedures withpremagnetization have been devel-oped for detection of internal andexternal damages in tubes madefrom ferromagnetic materials likecarbon steel, low-alloy steel, duplexor nickel alloys. The central item forthis specific challenge are testprobes that were especially devel-oped for this task, which can detectlocal as well as extensive corrosion,cracks and all known erosion typesand differentiate between them.Even damages near by or undervulnerable support plate areas canbe determined, and their depth can

be identified with fair accuracy. Thisis a decisive advantage compared tocompeting NDT procedures likeremote field tests (RFT) for instance.Test speeds of up to 70 tubes perhour (average 30 to 40 tubes perhour) can be achieved. Even damageslike cracks and corrosion in the tubesheet area are detected with specialrotating probes. Fair tube cleaningis still necessary, but by far not ascritical as for IRIS testing. Onlymagnetic and electrical conduc-tive deposits must be removedfrom the tubes´ interior. Probeaccess with 1 mm undersizeacross the entire tube length mustbe ensured.

Prerequisites / Limitations:

Several types of defects present atthe same time make interpretationof the eddy current signals moredifficult. For this reason, experi-enced inspection personnel is re-quired. The depth of externaldefects can only be determined bysignal amplitudes compared toconventional eddy current. The testaccuracy resulting from this can beslightly below that of conventionaleddy current procedures (depend-ing on the tube material, tube di-mension and type of defect).

10

CorrosionDamage of heat exchangers can be

caused by a large number of factors.

One of the main causes of heat ex-changer damage – the worst casebeing a leak – is corrosion. Corrosionis described by DIN EN ISO 8044 as„the reaction of a metallic materialwith its environment, which causesa measurable change of the mate-rial and can affect its function (...)“.Amongst others, the standard de-fines 37 types of corrosion, includingpitting corrosion, stress corrosioncracking and erosion corrosion.

Pitting corrosion mostly occurs inpassivated materials with an elec-trolyte present. The occurrence isstrongly influenced by high tem-peratures, low electrode potentialof the material as well as a low pH-value of the electrolyte, i.e. the fluid,and a low oxygen concentration in

the electrolyte. For the occurrenceof stress corrosion cracking, threeconditions must be met: On the onehand the material must be suscep-tible to stress corrosion cracking.Furthermore, tensile stresses in theform of residual stresses or exter-nally applied stresses must bepresent. Moreover, a specific corro-sive agent must be present; foraustenitic steels these are fluidscontaining chloride and for copperzinc alloys these are ammonia,amines, nitrites or nitrates.Theerosion corrosion not only dependson mechanical material character-istics, but also on current conditions,such as speed and geometry, as wellas on possible specific substanceconditions like dissolved solid par-ticles in fluids or formation of dro-plets in gases, which can result inabrasive loss.

Damages through Corrosion/Erosion

Corrosion/Erosion

Pitting corrosion

Stress corrosion cracking

Inlet erosion

Baffle erosion

Steam and wet steam

erosion

Droplet erosion

ErosionBy definition, erosion or wear and

tear is the progressive loss of ma-

terial from the surface of a solid

object. If mechanical forces affect

this base body, i.e. contact and re-

lative movements of a solid, liquid

or gaseous counter body, this results

in erosion.

Amongst others, this undesiredchange of the surface occurs ontubes and tubeworks. Wear and tearis one of the main reasons for tubedamages and causes the associateddowntimes of heat exchangers andtheir connected components. Ero-sion on pipes can be manifold, withmore or less severe consequences.

Erosion at support plates

This kind of tube damage is a typeof erosion that is caused by supportplates and insert plates that bangagainst the tubes. Support platesnormally support and stabilise thefitted tubes in common heat ex-changers. However, under certainconditions, for example if there is

clearance between boring and tubeor if other thermal and mechanicalinfluences are present, the tubescan vibrate in the support platesand get damaged due to the banging,and thus wear out. This quicklyresults in undesired leakages, withassociated financial and possibleenvironmental damages.

Inlet erosion

Particularly the first inches of a heatexchanger tube are subject to se-vere erosion stresses. This is due tothe fact that the influx of media isexposed to strong velocities andturbulences on the first few inches.These in turn can result in danger-ous thinning out of the inlet area,causing erosion.

Steam and wet steam erosion

Steam erosion is mostly found onthe external of heat exchangertubes, which are subject to steam orcondensate. Depending on the de-sign of the cooler or heat exchanger,there could be increased steam

concentrations at the support platesor the free tube areas, which in turnresults in leakages.

Erosion through deposits and inclu-

sion of foreign objects in tubes

If deposits or foreign objects accu-mulate in a tube, the inflowingmedium washes around these.This results in velocities and turbu-lences directly behind the pointblocking the free flow. In combina-tion with water or abrasive particles,this can lead to severe wear andtear.

Droplet erosion

Erosion through droplets mostlyoccurs on power plant condensers.Due to condensation, microscopicsteam droplets form, which hit theexternal tube surface with tremen-dous speed and energy. The forceof these droplets can be so high thatthe tube surface is damaged withpinholes that can result in leakages.

11

TUBULAR

INSPECTIONS

Applications of tubular inspections

High-pressure tubes

Specifically for high-pressure tubes,

i.e. stainless steel pipes with a wall

thickness over 5 mm, DELTA TEST

has realised a test system for

complete control.With this, cracksand material homogeneities aredetected in one pass on the internaland external surface of the tubeand documented with precise lo-cation via C-scan. For this, an ad-justable and mobile test device isavailable in our efficient laboratory.

Tube bends and

U tube heat exchangers

The probe systems developed by

DELTA TEST enable damage de-

tection in tube sections that are

difficult to access. For this, rotat-ing as well as integral probes in aflexible guideway system are used.The probe system is able to passthrough several tube bends andovercome changes of the inner tubediameter (swaging). This is difficultto realise with other NDT methods.Testing U tube heat exchangers isvery difficult due to the tube sec-tions bent to different degrees.Standard sensors cannot be used inthese bends, but specifically ad-justed, flexible sensors are required.Additionally, U tube coolers canremain in their casing, which meanssignificantly reduced costs fordismounting.

Expanded tube sections

Testing tube ends in expanded or

tube sheet areas is a big problem

for integral standard eddy current

probes. DELTA TEST has developeda rotating probe system specificallyfor this challenge. It enables us totest paramagnetic as well as ferro-magnetic tubes in the tube sheetarea for cracks, corrosion or otherinhomogeneities. Testing tube endsis very efficient, whereby up to2,500 tube ends can be inspected,analysed and documented pershift/team. This rotating tube systemis of course also available for testingthe entire tube length, and forbended tubes.

Eddy current rotating probeAir-fin cooler tube

Condenser tubes

Condensers are used in power

plants, chemical plants as well as

various other industrial plants.

The paramagnetic tubes of brass,cupron-ickel, stainless steel or tita-nium usually present are testedhighly efficiently using eddy current(up to 700 tubes per shift/team).The accuracy of the test results is at± 10 %. In addition, the erosionthrough droplet erosion present inpower plants can be detected witha detection limit of approx. 0.2 mmdefect size with highly sensitiveprobes.

Heat exchanger tubes

Heat exchangers can be found in

almost all chemical plants. Whereother test methods like IRIS or RFTfail at testing airfin cooler tubes,DELTA TEST can competently performtest tasks. The advantage of thisinspection method is that the channelof the air cooler does not need to bedismounted for a test. Very precisetest results are achieved during in-spections of carbon steel tubes,as the cooling fins do not affecttesting.

Tube sheet

12

to be carried out properly, and thatthe resulting measured values do notachieve the required resolution.

Ultrasonic testing (e.g. with an IRISsystem) for example presupposesthat the IRIS system is preciselyinserted in the centre of the tube andthat the tube to be tested is com-pletely filled with water, to ensureprecise connection. Particularly inbent sections, these conditions can-not be met. For the above reasons,together with TÜV Süddeutschland,DELTA TEST has developed an inter-nal test system, based on the eddycurrent method, which has alreadybeen successfully used for morethan 10,000 tubes.

This procedure includes an rotatingeddy current probe technique,which scans the internal surface ofthe tubes seamlessly up to an in-serting depth of approx. 20 m. Thiscovers the first tube bend and pos-sibly also the complete second one.Normal firmly adherent protectivelayers do not affect testing. Onlycrude inhomogeneous depositsmay have to be removed with ahydrojet or chemical cleaning beforetesting. The eddy current probe wasdesigned specifically for the defecttype to be detected, so longitudinallyoriented crack-like defects from a

Technical drawing of a typical test object

Boiler tube inspection

defect depth of approx. 0.5 mm cansafely be detected.

Additionally, also small corrosion pitsare detected. The tests results sofar on more than 10,000 tubesconfirm the excellent detectionsensitivity and good interpretabilityof the eddy current rotating probemethod. For this reason we regardthe eddy current method as suitedto significantly increase the evalua-tion safety on the integrity of theboiler tubes.The probe system consists of anumber of centering elements on a

flexible hose and the rotating sensoritself. These centering elementshave a system for automatic selfpositioning on the surface to betested.During testing, the detecteddata are compared to the data ofthe calibration bodies.

The results of the analysis arestored in a table as well as in theDELTA TEST documentation soft-ware.

Probe for boiler tube inspection

Finned boiler tubes

Boiler and furnace tubes Due to a severe steam boiler deto-

nation in October 1994 near Bonn,

Germany, at which six people lost

their lives, special tests of boiler

tubes were called for by the respon-

sible Federal and Federal State Au-

thorities. According to this, at leastall three ascending tubes up to andincluding the first bend were to besubjected to a visual internal test,supplemented by endoscopy. Inaddition, a radiography test was tobe performed at 20% of the bends.

Due to the usually present coatings(protective coating, furring etc.), theendoscopy could not always achievethe required detectability of thedamage typical for the accident inBonn: longitudinally oriented strain-induced crack corrosion. Radiographytesting as well as ultrasound testingcould also not always be sufficientlyperformed due to hampered localaccessibility. One disadvantage ofthese test methods is that the insu-lation must be removed for the test

13

TUBULAR

INSPECTIONS

Tube sheet

Alternative tube testing methods

IRIS – Internal Rotating Inspection System

IRIS is a technique that can be

applied on both ferrous and non-

ferrous materials and even on non-

conductive materials like plastics.

With IRIS the remaining wall thick-

ness of tubes can be accurately

measured. IRIS is more accurate

than other tube inspection tech-

niques and has the advantages of

presenting information about the

geometry of defects. Local defects

and wall-loss on both sides of the

tube can be accurately measured.

Defects under support plates can

be measured without any limitations

and IRIS allows detection of corro-

sion and thinning on a wide range of

tube diameters (ID 14,5 – 76 mm ...

0.57" - 3.0") and wall thicknesses

(1.25 - 8.0 mm … 0.06“ - 0.31“)

depending on the tube OD.

Fields of Application

The IRIS technology is mainly used

as an analysing tool in combination

with other techniques such as

conventional eddy current or sat-

urated eddy current. Due to its low

inspection performance (6 – 12

tubes / h) only few selected tubes

shall be IRIS tested in order to

analyse or confirm results from

other NDT techniques. Furthermore

IRIS is the only suitable technique to

detect defects within the tube

sheet area of heat exchangers with

C-steel tubes (air fin coolers).

Theory

The probe used in IRIS examination

is made up of a centering device, an

ultrasound transducer and a rotating

mirror. An ultrasound pulse will be

generated in the transducer that is

mounted in axial direction, then A 45

degree rotating mirror in the probe

will guide the sound bundle towards

the tube wall. Next an ultrasound

reflection (echo) will take place at

the inner and at the outer wall of the

tube. These echoes are reflected

back and processed by the equip-

ment. The time between these two

echoes represents the wall thickness

of the tube. Knowing the sound

velocity in the material under test

enables accompanying wall thick-

ness to be calculated. Water is then

used to rotate the probe mirror and

is also needed as a couplant between

the transducer and the tube wall. A

calibration standard of the same

material and dimensions as the

tubes to be examined is used to

check the IRIS system response.

After an inspection an “on-site” re-

port detailing the condition of each

tube will be presented to the client.

Limitations

IRIS is not suitable/reliable to detect

small pittings and cracks. It is not

or only hard to apply in confined

space. Bended tubes (U- tubes)

cannot be inspected within the

bended area. Tubes to be tested

have to be perfectly clean to the

bare metal in order to acquire

adequate data.

14

Videoscope inspection of tubes

Videoscope inspection / Leak Videoscope inspection / State of cleaning

The visual inspection or visual test-ing (VT) in terms of non-destructivetesting methods is the optical qualitycontrol of a product (tube, shell,weld) through a technician qualifiedand certified according to ISO 9712.The type of visual inspection can beadapted and defined as per cus-tomer's requirements. For instancean inspection can be done foracceptable or rejectable material-inhomogeneities such as corrosion,cracks or leakages or a tube cleaning

quality control. The visual inspectionis one of the most important toolsfor the root cause analysis of defects.It can be used to clearly determinedefect geometry and orientation toget conclusion on the defect mech-anism. Visual testing gives out-standing possibilities to confirmand underline defects or indica-tions, previously found with otherNDT methods like eddy current orultrasonic by means of expressiveimages.

Because of the fact that integralNDT methods like eddy current orIRIS are much more suitable for a fullcoverage inspection of larger areas(tubes) we use the visual testing forthe verification of defects, cleaningcontrol or random spot check only.

The use of visual testing makes itpossible to inspect tubes as well asother components which are difficultto access with conventional tools.

By means of state-of-the-art videotechnology, combined with qualifiedpersonnel certified according to ISO9712, DELTA TEST guarantees to allclients a competent visual inspection,defect analysis and documentation.

Video probe

15

TUBULAR

INSPECTIONS

As none of the preferred test meth-ods for tube inspection can detectleaks, DELTA TEST has developed aspecial system, which can detect orexclude smallest leaks with greataccuracy by pressure testing thetubes. In this procedure, the tubesare sealed off at both tube ends witha quick acting closing plug. A sen-sitive digital gauge is mounted tothe system, which in case of a leakcan immediately detect a pressuredrop in the millibar range.

The plugs developed by DELTA TESTseal the tube to be tested 100% andhave a resistibility up to an excesspressure of approx. 6 bar. A sensi-tive digital gauge is mounted to theequipment, which in case of a leak

Leak testing of tubes

can immediately detect a pressuredrop in the millibar range. Within afew seconds, the tube to be testedis filled (pressurized) with excesspressure air of approximately 2 bar(29 psi). If the tube has a leak, a de-crease in pressure will be detectedinstantly. Otherwise the applied airpressure remains constant throughvalves in the tester. Due to the ex-tremely quick response time of thissystem, test speeds of more than100 tubes per hour can be achieved.

Delta Test is also using vacuum test-ing equipment for the detection oftube leaks. This leak testing equip-ment is very safe to use because avacuum is used instead of excesspressure. By using a handy vacuum

gun a negative pressure of approxi-mately -0.9 bar is created withinseconds. The use of the vacuumtester is slightly faster than the useof the positive pressure equipmentand more than 120 tubes can betested per hour (depending on theinternal tube volume and the leakrate to be detected). The system isvery easy to use and does not requirespecial preparations. Just a connec-tion to 6 - 8 bar compressed air isnecessary to operate the equipment.

DELTA TEST – We make surface cracks visible.Non-destructive testing for surface cracks is particularly required in heavily used areas. This includes surfacecrack tests, amongst others on tubeworks, boilers, reactors and turbine blades in the secondary and primaryarea of nuclear power plants, flue gas desulfurising plants and all other industrial plants.

In this difficult area, DELTA TEST can reliably detect even the smallest defects in inaccessible test locations,and document these conclusively. In addition to using state-of-the-art eddy current technology, we use special,high-resolution sensor systems. You can trust DELTA TEST when it comes to safe surfaces. >>

17

SURFACE CRACK INSPECTIONS

DELTA TEST has many years experi-

ence in testing turbine blades in

power plants or flue gas desulfuris-

ing plants. The non-destructivetesting of turbine blades is particu-larly important in the heavily usedareas of small cross sections, i.e.edges. By using necessary coolingsystems, the volume able to take aload is reduced again, so that loadsand crack probability can increasefurther. While the large blade surfaces

Welded seams are an artificial fixed

connection between two compo-

nents. Due to manifold stresses andcomplex load processes, the area ofwelded seams is particularly at riskto develop cracks and cause com-ponents to fail.

Grinded as well as ungrinded weldedseams can be tested with the eddycurrent probes adjusted to the surfacegeometry. Wall thicknesses up to 20mm (material-dependent) and crackdepths from 0.1 mm can be reliablydetected with suitable test systems.Welded seams of carbon steel, stain-

less steel as well as INOXYDA havealready been successfully tested byDELTA TEST. Even hot tests up to600 °C can be realised with our testsystem and respective personalprotective equipment.

The inspection of austenitic weldseams was a big challange sincemany years. Delta ferrite within theweld seam made a serious inspec-tion almost impossible. Delta Testhas developed special probes whichmakes the inspection of austeniticwelds for cracks (longitudinal andtransversal) possible.

can be inspected easily with con-ventional eddy current test systemsof surface crack tests, special sen-sor systems are indispensable forthe heavily used edges. The edgesof the turbine blades in their mountedstate are tested for cracks by usingspecial eddy current sensors, andthe crack depth of the found flawsis determined. Documentation canbe in simple lists with good/badcategories or by graphical display.

Turbine blades

Welded seams

Turbine

SURFACE

CRACK INSPECTIONS

Applications:

Turbine blades

Weldet seams

Sealing surfaces

Surfaces and vessels

Inspection of weldolets

or hot surfaces

Rolling bearing inspection

Brake discs

Rail Inspection

Eddy Current Array technique


Components for the automotive

industry are subject to highest

quality standards. Delta Test hasdeveloped high-sensible, problem-related inspection techniques todetect even smallest irregularitiesalready prior production.

We inspection ball or rolling bearings(Material 100Cr6) in the area ofabutting face or running surface forcracks with a sensibility of 50 μm.

Testing sealing surfaces for cracks

and determining the crack depth

are also included in DELTA TESTS

range of services. To perform thetests, it is vital to guide the probesystem coplanar to the test surfaceand at always the same distance.For this, flange diameters from DN50 mm up to DN 750 mm, whoseorientation and position is arbitrary,are tested. This diversity of taskswas achieved through combination

of a probe bracket and guide prin-ciple with a very effective sensorguide: with the superposition oftranslational and rotatory move-ment of the sensor, faults orientedin any direction are detected.

The same equiment can also beused for the inspection of bores andthreads.

Sealing surfaces

18

Roller bearing inspection

Another part of non-destructive

testing in the automotive industry

is the inspection of safety-critical

components.

Delta Test has a technique for fastand efficient testing of carbon steelbrake discs for sub-surface defectsin their portfolio since 2012.

Brake disc inspection

19


"Weldolets" are butt weld connec-

tions which serve minimisation of

stress peaks as well as integral

reinforcement. The ferritic weldedseams are tested for cracks fromthe outside, whereby the often highoperating temperature of up to 540°C poses a particular challenge tothe test system and the testers.To perform the test, DELTA TEST hasdeveloped a simple and robust sys-tem which serves as probe guide

and enables 3-axis position tracking.The position data and the eddycurrent test data are fed into thesystem and processed there as aC-scan. The decisive advantage isthat this test is possible duringsystem operation. Cooling downand starting up phases can beavoided and the test is independentof idle phases.

Inspection of „weldolets“ and hot surfaces

Hot bend testing manipulatorSURFACE

CRACK INSPECTIONS

Weldolet inspection with special personal protective equipment

This manipulator is designed for the

inspection of the surface of bended

pipework with diameter of 6 - 8 inch

under hot temperature up to 515°

celsius. It can be used on austeniticand ferritic materials. Surface de-fects as well as sub-surface (only onaustenitic material) can be detectedwithin the base material and theweld.


Rail inspection

While in operation railway tracks

must meet many different require-

ments. Passengers expect safe,quiet, comfortable and reasonablypriced transportation. To keep thecosts low, the operating company isdependent on a long life cycle andlong lay-days of rails in the track. Inaddition, repairs and maintenanceexpenses of the track systemshould be as low as possible. How-ever, the rail life cycle is significantlyshortened by the formation ofcracks, wear or single defects. Sincethe introduction of the new directiveRil. 821.2007 at the beginning of2007 eddy current testing for thedetection of critical surface defects(Head Checks, Squats etc) has be-come compulsory.

Approach

Eddy current testing is a useful en-hancement of the proven ultrasonictest. It is able to test those areas ofthe rail, in which test systems basedon ultrasonic are unsuitable due tophysical laws. Precisely speaking, itis the surface area up to a depth ofapprox. 2.7 mm on the upper sur-face of the rail as well as on theguiding surface that is consideredas “Dead Zone” in the ultrasonicfield and considered as very criticalfor surface defects, such as HeadChecks, Squats and Belgrospis.

Inspection Technique Applied

With our own measuring draisines(track motor cars) of the PLR com-pany (WPG II = Eddy current testequipment) Delta Test is able to de-tect and report these near-surfacedefects in critical areas on maintracks and in switches. Head Checks

are displayed graphically via mileageand/or tachometer indications sec-tioned by number and depths in 1 mareas in evaluation tracks of 100 mlength. A GPS receiver enables theallocation to exact locations. Theevaluation software makes it pos-sible to assess the data on or offline.

By wear and zero line adjustmentthe most different rail types can besafely evaluated, no matter if theyare new or already worn. Batteryoperation guarantees utmostmobility combined with an easyassembly of the “draisine” madeout of light aluminium and CFRP.

Rail cross-section

20


21

The eddy current array technique

(ECA) is a derivative of conventional

eddy current testing and shares the

same electromagnetic/inductive

principles of eddy current.

The word “array” means that in

comparison to a single coil sensor

many adjoining eddy current coils

are forming a coherent eddy current

assembly. The decisive advantage of

Eddy Current Array Technique (ECA)

Conventional eddy current vs. ECA Array-Technique T/R-Circuit Mode

ECA probes is their larger coverage

compared to single coil probes and

thus a faster and more cost efficient

scanning for the client.

SU

RFA

CE

C

RA

CK

INS

PE

CT

ION

S

The Eddy Current Array technique

uses a multiplexer (MUX) to excite

the single coil elements in a pre-

defined scheme to leverage the

probe’s width. Multiplexing also

minimizes the interference between

coils in close proximity (mutual in-

ductance) and maximizes the res-

olution of the probe. Another

advantage is the fact that each coil

element is able both to transmit

and/or receive eddy current signals

(transmit/receive circuit). By this

means different circuit modes can

be realized which enables the tech-

nique to detect cracks or corrosion

independently of its orientation in a

single pass. The data-acquisition is

linked to position-encoders. Thus

high inspection reproducibility will be

archived whereas the risk of untested

areas will be minimized at the same

time. An expressive full coverage 2D

or 3D C-Scan report of all tested

areas is another advantage of the

ECA technique.

High inspection speed, rapid scanning

High probe coverage, high test reliability

Independent for defect orientation through intelligent multiplexing

Probes can be adapted to complex geometries

Inspection without physical movement possible

Different inspections in one pass

Expressive 2D and 3D C-Scans for full coverage reports

High reproducibility

Encoder-based data acquisition

Advantages of ECA

DELTA TEST – We will find a solution for your inspection problem.

Special tasks require special solutions. For this reason, DELTA TEST is your competent partner in the field ofspecial tests, who meets your individual requirements with reliable solutions. By using state-of-the-arttechnical equipment, we can perform all compulsory and desired tests on special components – from cylinderbores to screwed connections.

For this purpose, we use wired crawlers for example that can be precisely controlled and positioned and beused with very different tools and probes. You can thus be sure that we will find a solution for each of yourcomponents to be tested optimally. >>

23

SPECIALIZED INSPECTION

SPECIALIZED

INSPECTION

Crawler for inner tube testing

The crawler is used for semi-auto-matic mechanized testing of inter-nal and external pipe surfaces inpipelines, depending on materialand wall thickness. It ensures safetythrough early detection of pipelinedefects such as defects at weldingseams and adjacent heat-affectedzones as well as imperfections inthe base material (corrosion, erosion,cracks and deposits). Due to itscompact method of constructiondriving through and inspection of

pipelines with a maximum of 4bends is possible. In the straightsections, the maximum range is70 meters.

The manipulator (crawler) will beinserted into the test objecttrough existing openings andtightened with 6 axes in the pipeinterior via compressed air. Eachaxis has its own drive, which allowsthe crawler to move around thepipe in the axial direction.

Features

Available range of diameters: DN 80 - DN 450

for austenitic and ferritic pipe materials

insertion on valves or fittings can be precisely positioned by means of encoders

can be moved over branches allows the installation and operation of different tools and test equipment:- grinding tools- cleaning and vacuuming- internal visual inspection/Videoscopy

- eddy current testing

Applications:

Corrugated expansion

joint test

Drive shafts, Axle shafts,

Hollow shafts

Reactor pressure vessel

screwed connections

the sensor socket is designed modular and is easy to install and therefore all-purpose applicable in crawler systems

automatic retracting movements of the (test-) tools at power failure

ovalities of the tube inside surface may be covered by an automatic tracking system

defects from a depth of 1 mm can be detected regardless of its orientation

very good signal separation of surface effects (noise) and defect signals

test coverage = 100% of the tube inside surface

exact positioning and repeatability by precise encoder

additional integration of a video system at the crawler

adjustable lighting for camera orientation/visual inspection

Characteristics of an eddy current testing system

Testing sleeve shafts (e.g. for heli-

copter drives and aircraft industry)

involves the use of rotation manipu-

lators. With this, straight semi-fin-ished products – shafts and tubes –can be tested seamlessly and fullyautomatically for internal and exter-nal defects by two probe systemsthat can be navigated separately.

Both systems allow the creation ofC-scans of the entire tested surface.Test objects up to 3 m in length canbe tested. The test device is designeduniversally, so that similar test ob-jects can be tested with minoradaptation effort.


Chemical injection line (CIL) and coil tubing test

24

Testing chemical injection lines (CIL)

with eddy current serves protecting

against grooves, cracks and me-

chanical damages during the pro-

duction of semi-finished parts and

completion, and has already been

successfully implemented by DELTA

TEST for more than 10 years.

The test device is designed in sucha way that the line can be testedduring coiling up or down as initialor maintenance inspection withoutinterfering with the normal work-flow. For this, the test is performedwith several sensors as well as po-sition encoding sensors, so that theposition of defects can also be de-termined retrospectively.DELTA TEST does also have a specialprobe system with exchangeable

powerful encircling coils for the in-spection of special coil tubingsmainly used in the oil and gas in-dustry. Coil tubings have a similardesign compared to chemical injec-

tion lines but a bigger diameter. Ourequipment is suitable for ferritic ornon-ferritic materials with a diame-ter range from 19.05 - 50.8 mm(3/4“ - 2“).

Drive shafts, Axle shafts, Hollow shafts

25


SPECIALIZED

INSPECTION

Corrugated expansion joint test

A corrugated expansion joint is a

flexible, cylinder shape element

made from thin metal sheet for

balancing movement in pipeworks

which are caused in particular by

vibrations or thermal extensions or

shortenings. Due to the constantalternating loads, there can be da-mages in the form of cracks which

can cause the component to failand cause critical leakages. Fortesting this complex geometry,DELTA TEST has developed a probesystem which detects cracks andother material inhomogeneities inthe vulnerable areas.

Surfaces and vessels

To be able to test larger surfaces for

surface defects independent of

their geometry, use of a scanner is

recommended. This applies forexample to the surface of boilers,vessels or reactors. Our scannerscan be used on even, cylindrical andspherical surfaces and require

approx. two or four minutes forscanning the nominal area size A4or A3. Their high-temperature suctioncups can be permanently used upto 200 °C. The test results are dis-played and analysed as conclusiveC-scan images. Up to 8 m2 surfaceper shift/team can be tested.

Due to official directives in nuclear

power plants (KTA 32014), periodic

testing of certain components, e.g.

screwed connections at the reactor

pressure vessel, is compulsory.

This includes the bolts, their pistonand thread as well as the nuts andthe tapped blind hole. Due to thehampered test conditions, fully

automatic manipulators are used,which enable qualified testing of thecomponent and pictorial documen-tation via C-scan. The entire testequipment was developed andproduced by DELTA TEST.

Reactor pressure vessel screwed connections

Bolt manipulator in the laboratory

26

EINSATZBEREICHE

DELTA TEST – We help develop the future.Apart from its range of services in the field of eddy current technology, DELTA TEST is also successful inresearch and development. For this reason we can offer you a wide range of products and services which wewill develop customized to you.

In a continuous development process, our engineers strive to adapt our test methods, database and docu-mentation solutions to the high demands of the industry. Intelligent solutions as well as simple operation andefficiency of the hardware and software are characteristic for our test methods.

To ensure that we can still meet all demands in the future, we can rely on highly qualified employees andengineers in the respective specialist departments for electrical engineering, mechanics and softwaredevelopment. They are all working towards the realisation of our most important objective: to achieve thebest for our customers! >>

Conventional eddy current probe

Saturation eddy current probe Conventional eddy current probe Flexible

Multi differential eddy current probe

27

RESEARCH, DEVELOPMENT, PRODUCTION

For its own requirements as well as

according to customer specifica-

tion, DELTA TEST produces eddy

current probes for testing heat ex-

changer tubes from paramagnetic

and ferromagnetic materials. Thisincludes amongst others austen-ites, cupronickel alloys, titanium

alloys, brass alloys and ferromag-netic materials like steel, compoundsteel, monel. Furthermore, rotatingprobes and special probes like flex-ible probes for bend testing of Utube heat exchangers are produced.

Eddy current probes for tubular inspection

Rotational eddy current probe

Eddy current probes Special equipment Plugs for heat exchanger

and condeser tubes Certified reference defects

for eddy current and ultrasonic

inspection

Eddy current acquisition

software with automatic

signal analysis algorithm Advanced reporting software

for tubular inspections Advanced 3D-reporting for

surface crack inspections


PRODUCTION

Encircling eddy current probe with magnetic saturation

Rotational eddy current probe for tube diameter Di 97 – 103 mm


28

Eddy current probes for surface inspection

Surface scanning probe Pencil probe

Adjustable (T/R) surface probe

Concav surface probe with electrical magnetization Concav surface probe with permanent magnetization

High temperature surface probe Pencil probe for hard accessible areas

Adjustable (T/R) surface probe

29


Individual inspection problems re-

quire individually developed in-

spection systems. In case norespective test system is availablefor your specific task, we design anddevelop new test systems according

to your requirements. Please do nothesitate to contact our qualified em-ployees in the respective specialistdepartments for electrical engineer-ing, mechanics and software devel-opment.

Special inspection equipment


PRODUCTION

Crawler Di 80 mm

Powerful probe pusher Di 60 mm Flexible rotation probe Di 35-70 mm

Probe rotor 27 mm Small probe rotor 18 mm

Universal power supply and link between eddy current probes and third party instruments Crawler Di 150–250 mm

Thread/bore/flange inspection equipment

Plugs for heat exchangers and condenser tubes

Certified reference standards

30

If a tube should be found extremely

damaged during inspection, it must

either be replaced or sealed off:

"plugged".

Conventional sealing options usuallyinclude welding up of affected tubesas well as driving or screwing inplugs. DELTA TEST offers its cus-tomers a plug system up to max.140° C operating temperature, withwhich the plugs can be insertedquickly and easily, and later be re-moved again without further damageof the tubes or the heat exchanger.

For calibrating the test systems, for

eddy current tests as well as other

NDT methods, certified reference

standards with defined adjustment

errors are required. For this pur-pose, DELTA TEST produces certifiedreference standards from metallicmaterials through processing byspark erosion machining for its ownrequirements as well as by cus-tomer order.

The extent of the artificially createddefects follows individual customerspecifications and can be adaptedto the defects to be expected. Forthese tasks, a state of the art 3-axiseroding machine and qualified per-sonnel is available.

Inserting the plugs for secure sealingof the pipes is fast and straightfor-ward, special tools or personnel isnot required. Upon customer re-quest, we seal damaged tubes directlyafter testing.

Advanages: Rapid insertion through screwable design

Plugs are easily removable Special materials for high temperature use or aggressive media


31

Inspection software for automatic eddy current signal analysis

In the area of software develop-

ment, DELTA TEST constantly works

on powerful and highly sophisticat-

ed software for signal visualisation

and for automatic analysis of eddy

current signals. The test softwaredeveloped by us analyses theavailable eddy current raw data inrealtime and in the background andprovides the inspector with an in-

telligent and reliable tool. Thismakes testing heat exchangerseven more reliable. Human error orsignals that are difficult to interpretcan thus be reduced to a minimum.Automatic signal analysis duringtesting of paramagnetic tubes hasbeen a standard procedure forDELTA TEST for many years and isalways applied if possible.

The computer-controlled signalanalysis on ferromagnetic tubes(carbon steel, duplex, super duplexetc.) is a DELTA TEST developmentand is only offered by us. For this,special software with artificial in-telligence is used, which learns eva-luation and decision criteria fromthe inspector. The software analysesall available test channels in the

background in real-time, and eval-uates based on an independentlylearning software algorithm. Evenfor the challenging testing of ferro-magnetic tubes (carbon steel, duplex,super duplex etc.), the best possibletest results are achieved with this,and the risk of human error is re-duced to a minimum.

Eddy current signal processing and visualization software "EC-View"



PRODUCTION

Strip chart with automatic signal analysis

For the benefit of its customers,

DELTA TEST pays particular attention

to the documentation of eddy

current inspection data.

Analysis and reporting of the tubeinspection is ensured by our power-ful documentation software. Numer-ous documentation types likestatistics, tube diagrams, 2-D views,lists and extended comparisons areavailable at any time during in-spection.Surface crack inspections on tubingor welded seams are displayed inmeaningful and flexible 3-D docu-mentations. All documents areavailable as hardcopy as well aselectronically as PDF.

The documentation of a heat ex-changer inspections are provided bysoftware, which is developed andconstantly updated by DELTA TEST. This was primarily developed witheasy operability in sight, so that theinspector can get a quick and safeoverview of the test results on site.This way, customer requests of partresults of the test can be metquickly. All test-relevant data arestored in an open database formatand handed over to the customer asrequired together with the docu-mentation for further processing(e.g. in Excel or Access).Additional features can be realisedpromptly by our software develop-ment team.

Documentation of heat exchanger inspections

Documentation of a heat exchanger in-spection by the "VirtualTube" software de-veloped by DELTA TEST and specificallyadapted throughout many years of painstak-ing work.

32


33

The documentation of surface crack

inspections on tubes or welded

seams is also created in meaning-

ful and flexible 3-D-documenta-

tions. These are available via anyInternet browser and are thus easilytransferable to the customer.

3D-documentation for surface crack inspections

3-D documentation of pipeworks and vessels through freely scalable CAD drawings. The documentation can be opened by the customer via Internet browser and printed. It is also possible to rotate and enlarge the displayed test objects with the mouse. Detailed photographs can be opened at the click of a mouse.



PRODUCTION

COOPERATIONS / CERTIFICATION

34

DELTA TEST cooperates worldwidewith well-known manufacturers,service providers and research insti-tutions, to provide our customerswith innovative test methods andtest services of the highest qualityat all times.

Worldwide services

Excellent security

DELTA TEST is a member of the'Deutsche Gesellschaft für zerstö-rungsfreie Prüfung' (DGZfP, GermanAssociation for non-destructivetesting) and certified according to

ISO 9001 Accredited testing laboratory

ISO/IEC 17025 SCC OHSAS 18001 KTA 1401 Certificate of Approval

Deutsche Bahn Prequalification Sellihca Prequalification Connexio Prequalification ISNetworld

(North America, Canada)

Al-Jubail,Saudi-Arabien

Universität Hannover/IW

Hannover, Deutschland

Universität Magdeburg/IWW

Magdeburg, Deutschland

EXWET S.A.R.L.Prof. Dr. Zaidi

Marokko

NPICO

Kairo, Ägypten

PLR Prüftechnik Linke und Rühe

Magdeburg, Deutschland

Turboplus

Budapest, Ungarn

TÜV SüddeutschlandBereich Bau und Betrieb

München, Deutschland

Sven SeverinSvets & Kvalitetsteknik AB

Trollhättan, Schweden

Taprogge

Wetter, Deutschland

35

DELTA TEST GMBH

DELTA TEST

DELTA TEST – What can we do for you?DELTA TEST guarantees short re-sponse times from the initial enquirythrough to job execution, andfurthermore optimally short testtimes with at the same time highquality test results.

Our aim is to provide informationthrough high-quality and reliabletest results, which will help you tolower your costs for maintenanceand repair long-term.

With this reliability and our availabil-ity around the clock, we can achievea relationship of complete trust withour customers.

Our national and international successis based on highly motivated, certi-fied and qualified employees andmodern equipment, developmentachievement and the ability to im-plement innovative ideas for youand with you.

We look forward to working with you!

DELTA TEST – a name standing forqualified, non-destructive materialtesting by using the eddy currentprocedure.

Since its foundation in 1988, DELTATEST has been carrying out state-of-the-art eddy current test ser-vices, according to customerrequirements and based on re-spective norms and standards. Weare specialised in all kinds of eddycurrent tests and provide thesearound the world. Tests of paramag-netic and ferromagnetic heat ex-changers play a significant part inthis.

Founding year

1988

Legal form

GmbH

Share Holders

Werner Sievert

Eckard Köllner

Stefan Köllner

Daniela Sprakties

Employees

60

Trade register

Amtsgericht Lüneburg,

HRB 100387

VAT Reg.No.

DE 115117580

Jurisdiction

Celle

DELTA TEST GMBHBrigitta 15

D-29313 Hambühren

GERMANY

Phone: +49 (0)5084/9301-0

Fax: +49 (0)5084/9301-20

www.deltatest.de

[email protected]

NOTES

NON-DESTRUCTIVE MATERIAL TESTING · DELTA TEST – We do eddy current. DELTA TEST – a name that stands for qualified, non-destructive material testing using the eddy current procedure.

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