Ultrasonic Couplant Selection - Radiatronics NDT Inc.

Ultrasonic Couplant SelectionA Presentation by Sonotech, Inc.(800) 458-4254www.sonotech-inc.com© 2007 Sonotech, Inc. All rights reserved.

Selecting the Couplant That isRight for Your Application

How to Choose AmongCouplants10 steps to assurecouplant selection

One of the main goals of non-destructivetesting is to cause no harm to the part beingtested or to the environment.

Step 1: Corrosion InhibitionSlide A The couplant selected must not cause corrosion. Corrosion damage is often not visible (crevice corrosion;hydrogen embrittlement; titanium stress corrosioncracking at elevated temperature). Corrosion may take place over a long period (months oryears) and/or require operating environments so thatambient corrosion tests may be inconclusive. Be particularly cautious with low alloy, high strength steel(hydrogen embrittlement) such as bolts, landing gear, andtitanium components which will be subjected to elevatedtemperature (stress corrosion cracking).

Step 1: Corrosion InhibitionSlide B Use accepted corrosion specifications as a guideline forcouplant suitability Hydrogen Embrittlement of Steel ASTM F519 Titanium Stress Corrosion Cracking ASTM F-945 Hot Corrosion Testing PWA 36604-D Typical Alloys Tested: Ferrous based alloy (AMS6359), Aluminum (AMS 4037), Magnesium (AMS4375), Waspaloy (AMS 5544), Hastelloy X (AMS 5608),Haynes 188 (AMS 5608), Greek Ascoloy (AMS 5508)

Step 2: Acoustic Impedance and improves coupling on very rough and curvedsurfaces. Very high acoustic impedance (Z) couplants provideoptimum results for testing concrete and rough,pitted, corroded metal surfaces.

Step 3: Viscosity Higher viscosity couplants provide enhanced coupling andreduced surface noise on curved surfaces. Viscosity selection involves inspector exposure (overheadsurface drips), adhesion to the part (vertical surface) andease of application (spreading couplant over the area to beinspected). Viscosity measurements are a relative indicator betweencouplants using the same polymers, (i.e., comparingcouplants that use acrylic polymers). Couplants usingdifferent polymers (i.e., cellulose versus acrylic) have verydifferent flow (rheology) characteristics and do notnecessarily relate by viscosity measurement numbers.

Step 4: Temperature Range Temperature Range Determine the temperature of the surface youare testing Verify the length of time you will need toconduct the test and whether the couplant willbe left in place Some couplants have a minimum operatingtemperature due to 2 or 3 component eutecticsystems If freezing point is a concern, choose a couplantthat meets that temperature requirement

Step 5: Drying Time orEvaporation Rate Drying Time Couplant liquid retention reduces the need toreapply and increases efficiency A higher couplant upper limit temperatureresults in longer drying time The drying time becomes a crucial factor whenperforming a lengthy inspection

Step 6: Couplant Removal Consider if the couplant is to be removed: Wiping incomplete removal Water Wash for water soluble products, worksbest when performed before couplant dries.Dried couplant films can be removed withpressure washing Solvents select based on the couplant

Step 6: Couplant RemovalContinued Leave couplant on the part in many applications,couplants are selected for long term compatibilityand not removed after inspection. If it is mandatory that all traces of couplant beremoved, consider using a couplant with afluorescent tracer and inspecting the part withultraviolet light after cleaning.

Step 7: Toxicity Is there potential for animal contact or ingestion?If so, select an appropriate low toxicity product.Never use ethylene glycol antifreeze to lowerfreezing point or extend drying time. Ethyleneglycol is sweet, toxic to animals andenvironmentally negative. For pharmaceutical and food processingequipment, use a couplant with claims specific forthe application.

Step 7: Toxicity Continued For high temperature couplants, beware ofproducts which contain fluorocarbons as they canon the MSDS.

Step 8: EnvironmentalSensitivity When couplants will be introduced directly intothe environment without sewage treatment,consider products designed for reducedenvironmental impact. Typically, these productswill have low (or no) nitrates, nitrites ortriethanolamine and the corrosion inhibitingsystem will not contain heavy metals or chromiumcomponents.

Step 9: Surface Wetting Surface Wetting If an oil film is present, the ideal couplantquickly cuts through the oil or grease film toprovide an unobstructed acoustic interfacebetween the transducer and test surface Couplants need a low surface tension to wet thesurfaceespecially on plastics

Step 10: Reliability Product consistency between and throughout batchesis critical. Drop by drop, gallon by gallon, batch by batch,product chemical uniformity is critical to corrosioninhibition properties. Choose a couplant provider that guarantees all couplantsare homogeneous throughout the entire batch ensuringproduct reliability. Choose a couplant manufacturer that is certified to ISO9001:2000 Consider a vendor audit of your couplant supplier

Matching Couplants to Specifications Couplants can be selected by the following criteria tomeet your specifications: Corrosion Inhibition Acoustic Impedance Viscosity Temperature Range Drying Time or Evaporation Rate Couplant Removal Toxicity Environmental Sensitivity Surface Wetting Reliability Cost

Corrosion Inhibition Couplants that offer superior ferrous corrosioninhibition: Sono 600 long term ferrous corrosion inhibition. Ultragel II Provides best ferrous corrosion inhibition and wettingbe left in place for an extended amount of time. Sonotrace Echogel

Corrosion Inhibition Couplants that have been tested and approved for HydrogenEmbrittlement to ASTM F519: Ultragel II Echogel Couplants that have been approved for Titanium StressCorrosion Cracking to ASTM F945 or equivalent: Ultragel II Soundsafe SonoGlide UP Couplants that have been approved for hot corrosion testing toPWA 36604D Ultragel II Soundsafe SonoGlide UP

Corrosion Inhibition A couplant containing a ferrous corrosioninhibition is critical for ferrous materials withrespect to rust prevention. Below are examples ofthe effect on cast iron.WaterUltragel II

Acoustic Impedance If inspecting metal: performance increases with higherimpedance. This effect is more pronounced on veryrough or curved surfaces. High Z has the highest acoustic impedance of allSonotech couplants Sonotemp has the highest acoustic impedance of thehigh temperature couplants Ultragel II has the highest acoustic impedance of thewater based couplants.

Viscosity Ultragel II, Soundsafe High Viscosity Good for any surface; highly stable couplantsexcept when testing in the presence of salt cake. For power plants and salt cakes we suggest: Echogel UT-X Powder SonoGlide}Contain a salt-resistantpolymer

Temperature Sonotech has a variety of high and low temperaturecouplants SonoGlide, the lowest temperature couplant is effective to-60º F (-51ºC) and Sono 1100, the highest temperaturecouplant reaches a maximum temperature of 1100º F(593ºC) Pyrogel has the broadest temperature range (-50º to 800ºF /-45º to 427ºC) SonoGlide has the broadest temperature range of the waterbased couplants. (-60º to 250ºF/-51º to 121ºC)

Flash Point & Auto Ignition Sonotech provides the auto ignition and flash point for eachhigh temperature product. Auto Ignition is the temperature at which asubstance ignites without other sources of energy.This is the temperature of interest in the use of anultrasonic couplant for thickness gaging or flawinspection, as most NDT is not done in the presenceof flame or sparks. The Flash Point is the temperature at which vaporsarising from the product will ignite when exposed toflame. This is the temperature of interest relating tostorage of products and their properties whenexposed to a flame.

High TemperatureTemperature When choosing a high temperature couplant, be sure toselect a couplant that has the broadest temperaturerange overlap with the expected test temperature For example, if you are testing between ambient and600ºF/315ºC, Sono 600 or Pyrogel would offer the mostconsistent results. Sono 900 would not work in thisexample because it develops coupling capability above600ºF (315ºC)

Temperature High Temperature Chart When reading the following chart, be sure todistinguish between thickness gaging and flawinspection temperatures. Contact time variesbetween the two. Thickness Gaging: (

Follow this chart for high temperature couplant selectionF -100 0 100 200 300 400 500 600 700 800 900 1,000 1,100SONO 600SONOTEMPPYROGELSONO 900SONO 950Thickness GagingFlaw InspectionSONO 1100C -73 -18 38 93 148 204 260 315 371 426 482 538 593

Ambient Temperature (Fahrenheit)Slow DryingFast DryingCostSoundclear20º to 200ºHigh PerformanceSonoGlide -60º to 250ºUltragel II -10º to 210ºCostUT-XPowderBetterPerformanceEchogelSonotrace25ºto 175ºSoundsafe 0º to 200ºBroader Temperature Range

Ambient Temperature (Celsius)Slow DryingFast DryingCostSoundclear-7º to 93ºHigh PerformanceSonoGlide -51º to 121ºUltragel II -10º to 99ºCostUT-XPowderBetterPerformanceEchogelSonotrace-4ºto 79ºSoundsafe -18º to 93ºBroader Temperature Range

High Temperature Testing(Fahrenheit Scale)High TemperatureStaticThickness Gaging,Flow MeteringSono 900: 600º to 900 ºSono 950: 600º to 950ºSono 1100: 700º to 1100ºDynamicFlaw Detection,Transducer in MotionSonoGlide: -60º to 250ºThermasonic: 0º to 325ºSono 600: 0º to 600ºPyrogel: -50º to 800º

High Temperature Testing(Celsius Scale)High TemperatureStaticThickness Gaging,Flow MeteringSono 900: 315º to 482ºSono 950: 315º to 510ºSono 1100: 371º to 593ºDynamicFlaw Detection,Transducer in MotionSonoGlide: -51º to 121ºThermasonic: -18º to 163ºSono 600: -18º to 315ºPyrogel: -50º to 426º

Low Temperature TestingSonoGlide:-60 to 250ºF(-51 to 121ºC)Long drying time, salt stable.Pyrogel: Low freezing point, broadest-50 to 800ºF temperature range(-45 to 427ºC)Echogel Winterized:-20 to 175ºF(-29 to 121ºC)Good long-term stability

Drying Time or Evaporation Rate SonoGlide Stays in place many hours or days after application,depending on the temperature Available in four viscosities - liquid to low viscositygel Ultragel II Has the longest drying time of the water basedcouplants Humex and UT-X Powder Shortest drying time because there are nohumectants

Purity and Reliability Sonotech offers the most used and specifiedultrasonic couplants in the world. Sonotech is ISO 9001:2000 certified Sonotech is an FDA GMP facility Sonotech ultrasonic couplants are approved to majorUT couplant specifications equipment ensure that all couplants are homogeneousthroughout the entire batch.

Couplants for Food/ PharmaceuticalApplications SonoGlide UP is recommended for testing foodgrade equipment and pharmaceutical processingequipment

Environmental Sensitivity Sonotech offers a series of Environmentally Benignproducts. These are particularly applicable to inspectionswhere couplant may be removed by weather andcome in contact with animals or ground water. Environmentally benign couplants are preferredunless specification, corrosion inhibition, acousticimpedance or wetting require the highestperformance properties.

Environmentally Benign Couplants Soundsafe SonoGlide Sono 600 Soundclear UT-X Powder Shear Gel Humex UT-X

Surface Wetting Ultragel II has highest wetting power of the waterbased couplants Thermasonic and Gel 3000 are the best wetting,water-free couplants

Cost Most Economical UT-X Powder Echogel UT-X UT-X Fe

GENERAL PURPOSECOUPLANTS

General Purpose Couplants Sonotech General Purpose Couplants: Are air bubble free Contain corrosion inhibitors for ferrous metals and arecompatible with aluminum and titanium alloys Are non-flammable and non-irritating. Leave low residue and can be easily removedimmediately after inspection with water rinse Have rapid surface wetting formulations

General Purpose CouplantSonoGlide FE and UP Preferred in many aerospace applications. Remain stable on corroded or salt covered surfaces and isrecommended for inspection of boilers when salt cake is present Compatible with a broad range of materials, including steel,plastics, and magnesium (UP) Useful for thickness gaging where a thin liquid film of couplant isdesired. Very slow drying and low freezing point. Available in four viscosities - liquid to low viscosity gel Temp Range: -60º to 250ºF (-51º to 121ºC) UP grade is appropriate for food and pharmaceutical equipment.

General Purpose CouplantUltragel II Most specified commercial ultrasoniccouplant in the world Increased acoustic impedance for reduced surfacenoise and increased acoustic transmission Best ferrous corrosion inhibition and wetting of Stable gel couplant, making it easy for use in flawinspection, thickness gaging, flow metering andacoustic emission testing Gel viscosity covers all inspection surfaceorientations Temp Range: -10º to 210ºF (-23º to 99ºC)

General Purpose CouplantSonotrace Glycerine-free mid-range couplant Best ferrous corrosion inhibition of midperformance water-based couplants Contains humectants to retard drying Available in three viscosities Good price:performance ratio Temp Range: 25º to 175ºF (-4º to 79ºC)

General Purpose CouplantEchogel Remains stable on corrosion or salt cake andis recommended for inspection of powergenerating boilers when salt cake is present Best ferrous corrosion inhibition of low costcouplants Low cost couplant for volume use Glycerine-free couplant Temp Range: 27º to 140ºF (3º to 60ºC), availablewinterized to a temperature of -20º to 150ºF (-29ºto 66ºC)

ENVIRONMENTALLYBENIGN COUPLANTS

Environmentally Benign Couplants All Sonotech Environmentally Benign Couplants: Are air bubble free Provide a high level of operator safety Have low skin irritation potential because they contain noharsh surfactants, dyes or fragrances The likelihood of skin irritation has been reduced through theuse of cosmetic grade ingredients Sonotech developed environmentally benign couplants tominimize impact on the environment. These couplantscontain biodegradable materials safe for disposal.

Environmentally Benign CouplantSoundsafe Offers highest performance of Sonotechs waterbasedenvironmentally benign couplants Increased acoustic impedance for reduced surfacenoise Has high humectant level to slow drying and providetransducer lubrication Has a gel viscosity which holds on a majority ofoverhead and vertical surfaces Available in High Viscosity formulation Temperature Range: 0º to 200º F (-18º to 93ºC)

Environmentally Benign CouplantSoundclear Contains humectants to slow drying and provideexcellent transducer lubrication Gel viscosity holds on a majority of overhead andvertical surfaces Good surface wetting capability Environmentally benign formula Good price/performance ratio Temp Range: 20º to 200º F (-7º to 93ºC)

Environmentally Benign CouplantUT-X Remains stable on corrosion or salt cake and isrecommended for inspection of power generatingboilers when salt cake is present. Low residue Cost effective Temp Range: 32º to 125ºF (0º to 52ºC)

COUPLANT CONCENTRATES

Couplant ConcentratesUT-X Powder UT Couplants Most Cost Effective Ultrasonic Couplant Reduces shipping costs by up to 75% No drum disposal expense Easy To Use Pre-measured 1-gallon and 5-gallon packets Compact storage Viscosity can be varied by adjusting water addition Mixes quickly, with no lumps or long-lasting airbubbles Environmentally benign Contain no humectants, including glycerine

Couplant ConcentratesUT-X Powder UT Couplants Economical and easily mixed powder UTcouplant for non-ferrous inspection or whereferrous corrosion is not a concern Use as primary couplant Ideal for remote inspection sites and as emergencybackup couplant High level operator safety Preservatives added to maintain viscosity andprevent microbiological degradation of product Temp Range: 32º to 120ºF (0º to 48ºC)

Couplant ConcentratesUT-X Powder, UT-X - FE Use as primary, low cost couplant in high volumeapplications where ferrous corrosion is a concern. Compatible with aluminum and titanium Temp Range: 32º to 120ºF (0º to 49ºC)

HIGH TEMPERATURECOUPLANTS

High Temperature Couplants None of the Sonotech high temperature couplantscontain perfluorocarbons or fluorinatedmaterial. High temperature couplants are manufactured forthickness gaging, flaw detection, flow metering andacoustic emission at high temperatures.

High Temperature Couplants It is essential to select a couplant developedspecifically for UT high temperatureinspection. Greases contain many additives that are toxic,irritating to skin and cause environmental damage.They are not typically intended for skin contact.Examples of toxic additives to greases includeperfluorocarbons (i.e., Teflons, etc. - smoke plumeis toxic) and chromium based compounds (toxiccorrosion inhibitors). There are micro air-bubbles in greases, which expandwith temperature, and can both inhibit ultrasoundtransmission and cause artifacts.

Flash Point vs. Auto Ignition Auto ignition is the temperature at which a substanceignites without other sources of energy. This is themore important criteria for high temperatureinspection. The flash point is the lowest temperature at whichvapors arising from the product will ignite whenexposed to a flame.

High Temperature CouplantsSono 600 Superb safety profile, biodegradable formula Excellent long term ferrous corrosion inhibition Compatible with many magnesium alloys*(see slide 62) Very slow drying (months or years depending on temperature) Good price/performance ratio ViscosityBase fluid: 80 cps ---water-like consistencyFluid: 2,500 cps ---honey-like consistencyGel: 500,000 cps ---gel Smoke point: 650º F (343º C) Auto Ignition: 935ºF (502ºC) Temp Range: 0º to 600ºF (-18º to 315ºC)

High Temperature CouplantsSonotemp Best candidate for elevated temperature, longtermflow and acoustic emission metering use andfor rough surface thickness gaging. High acoustic impedance Low toxicity, non-irritating Smoke point: 475º F (256ºC) Auto Ignition: 1065ºF (574ºC) Temp Range: 0º to 700ºF (-18º to 371ºC)

High Temperature CouplantsPyrogel Provides high coupling over a wide temperature range forthickness gaging, flow metering, acoustic emission testing,and flaw inspection. Compatible with Base many fluid: magnesium 620 cps ---water-like alloys*(see consistency next slide) Viscosity Gr. 25: 150,000 cpsGr. 60: 550,000 cps ---gelGr. 100:>4 million cps ---thick gel High smoke point: 750º F (399º C) Auto Ignition: 960ºF (516ºC) Safety concern: B Broadest temp range: -50º to 800ºF (-45º to 427ºC)

High Temperature Couplants*Magnesium alloys Pyrogel, SonoGlide UP and Sono 600 are candidates formagnesium testing. We recommend specific corrosion or compatibilitytesting before using couplant on magnesium alloys. Request a couplant sample to evaluate.- OR - Sonotech can perform metallurgical couplantcompatibility testing on parts provided. ContactSonotech for details and a quote. 800-458-4254 www.sonotech-inc.com

High Temperature CouplantsSono 900 Provides rapid coupling for thickness gagingand flaw inspection. Offers fast coupling in a thick paste that adhereswell at high temperatures Viscosity: >4,000,000 cps Smoke point: 790ºF (421ºC) Auto Ignition: 990ºF (532ºC) Temp Range: 600º to 900ºF (315º to 482ºC)

High Temperature CouplantsSono 950 Provides coupling for thickness gaging andflaw inspection at high temperatures. Extended open time window for longer inspections Non-toxic, non-irritating formula providesinspector safety Viscosity: >3,000,000 (light paste) Smoke point: 850º F (454º C)/Auto Ignition: 1040ºF(560ºC) Temp Range: 600º to 950ºF (315º to 510ºC) Smokes less than Sono 900

High Temperature CouplantsSono 1100 Provides coupling for thickness gaging and flawinspection at extreme temperatures. Maintains acoustic coupling beyond 15 seconds togive ample time to obtain good thickness readings Reduced smoke Non-toxic, non-irritating formula provides inspectorsafety Viscosity: >3,000,000 (light paste) Smoke point: 850ºF (454º C)/Auto Ignition: 1160ºF(627ºC) Highest temp rating: 700º to 1100ºF (371º to 593ºC)

SPECIALTY COUPLANTS

Specialty CouplantsHigh Z Provides highest acoustic transmission into highimpedance mediums. Reduces surface noise and improves performance onrough metal surfaces, curved surfaces and concrete. Well suited to test curved, rough, pitted, or heavilycorroded surfaces Water soluble formula is available in both high andlow viscosity Temp Range: 0ºto 200º F (-18º to 93ºC) Very slow drying.

Specialty CouplantsShear Gel Transmits normal incidence shear waves Operator safe and environmentally benign formula Water-soluble Contains no VOCs, naptha, oil, hydrocarbons,glycerine or glycols Temp Range: 40º to 90º F (4º to 32ºC)

Specialty CouplantsGel 3000 Contains a fluorescent tracer that monitors scanoverlap, couplant application and removal usingan UV lamp, and confirms testing. Developed for aerospace (by Rockwell International)to test the space shuttle Available in 4 viscosity grades from liquid to gel Temperature range: 0º to 325º F (-18º to 163ºC) Water soluble, however, does not contain water

Specialty CouplantsThermasonic Rapid wetting, slow drying, water free, watersoluble couplant Temp Range: 0º to 325º F (-18º to 163ºC) Contains no VOCs, naptha, oil, hydrocarbons,glycerine or glycols

Specialty CouplantsHumex Humectant free, water based gel contains noVOCs, glycerine, glycols or other humectants Developed for applications where humectants areprohibited by supplier Meets GE Nuclear Energy Specification D50YP12, Rev.1 Temp range: 32º to 130ºF (0º to 54ºC)

UT WATER TREATMENTSERIES

Immersion UT AdditivesEchonox I:Corrosion InhibitorEchowet:Wetting AgentEchonox II:Corrosion InhibitorEchocide:Algaecide

UT Water Treatment SeriesEchowet Wetting agent, low foaming Lowers surface tension of water to half that ofuntreated water Releases air bubbles that cling to parts and interferewith sound waves Compatible with Echocide and Echonox II 1 gallon treats 400-800 gallons of water

UT Water Treatment SeriesEchonox I Highly effective ferrous corrosion (rust) inhibitorthat is compatible with most metals. Rinses off easily, or may be left on for continuouscorrosion inhibition Compatible with Echowet; not compatible withEchocide 1 gallon treats 65-130 gallons of water

UT Water Treatment SeriesEchonox II Highly effective ferrous corrosion (rust) inhibitorthat is compatible with ferrous parts Rinses off easily, or may be left on for continuouscorrosion inhibition Compatible with Echocide and Echowet 1 gallon treats 65-130 gallons of water

UT Water Treatment SeriesEchocide a combination algaecide and wettingagent Algaecide-inhibits growth of filter clogging algaeand bacteria to maintain immersion bath clarity Echocide is both an antimicrobial and a wettingagent. High safety level at recommended concentrations Compatible with Echonox II and Echowet Lowers surface tension of water, releases air bubblesthat cling to parts and de-airs immersion bath water

New Products Soundsafe High Viscosity Custom made product for over 10 years, added toproduct line in 2007. Available in a 3.2 oz. dispensing pump Very high viscosity gel Ideal for overhead and vertical surfaces

About Sonotech For over 30 years, NDT personnel around the worldhave trusted Sonotech couplants for a broad range ofultrasonic couplants in seven categories, including;High Temperature (to 1100 F), EnvironmentallyBenign, Specialty Couplants and ImmersionUltrasonic Products.

About SonotechBreadth of product line: With over 40 NDTcouplants, Sonotech offers a product to meet everyneed, from high performance to economical,extreme temperature (-60°F to 1100°F), humectantfree,water-free, fluorescent, high acousticimpedance, and products for immersion tank waterconditioning. No other company matches

About SonotechQuality: Sonotech has been assessed and registeredas conforming to the requirements of theinternational standard, ISO 9001:2000 QualityManagement Systems.Management: includes 15 full-time employees, many withadvanced degrees or education and training beyondhigh school, including a full-time, degreed QualityManager and a degreed Metallurgist with NDT levelIII (ultrasonics).

About SonotechExperience: Some Sonotech couplants have beenin use for 30 years (Ultragel II, Echogel). Millionsof inspections have been performed by thousands ofoperators worldwide on virtually every material andpart inspected ultrasonically with Sonotechcouplants.Chemicals: USP pharmaceutical grade humectantsare used in Sonotech couplants. In the higherperformance products (Ultragel II and Soundsafe),pasteurized, deionized water is used. Sonotechpioneered operator and environmentally benigncouplants with no VOCs, harsh surfactants, dyes orfragrances.

About SonotechProduct Support: Sonotech will provide you withfree samples, and literature to make certain the bestproduct is selected for each application. More than95% of all orders are shipped within 24 hours ofwww.sonotech-inc.com contains productinformation, downloadable MSDS and data sheetsand on-line ordering. Technical support is availableby calling (800) 458-4254.Fair pricing: Our products are priced to cover theinfrastructure required to support the quality and

Samples For a free sample of any of the products youve seen inthis program, please contact Sonotech.Sonotech, Inc.774 Marine DriveBellingham, WA 98225Phone: 360.671.9121 Fax: 360.671.9024Email: sonotech@sonotech-inc.comWebsite: www.sonotech-inc.com

This has been a SonotechProductionFor more product information visit our website atwww.sonotech-inc.com© 2007 Sonotech, Inc. All rights reserved.