Echo Ultrasonics can help you save time by ordering direct. We stock all couplants in all container sizes and offer same day shipping with worldwide delivery.
Echo’s commitment is to provide the highest performance and safety profile ultrasonic couplant at a fair price, or 10% less than the lowest competitive price for a similar performance couplant.
Selecting the best couplant for your application can reduce your costs. Along with Echo’s lowest cost guarantee, we can help you to select the best couplant to optimize:
- price vs. performance
- longer inspection windows
- less re-application required
- broader operating range
- no residue to clean up later
Improve Safety and Performance
- SuperSoniX™: is Echo’s highest performance water-based couplant that doesn’t thin with corrosion salts and reduces the need for re-application.
- EchoPure™: is ideal for phased array (reduces artifacts) and very cold or warm inspections (-60° to 350° F / -51° to 176° C).
- EchoTherm™ Extreme: Eliminates auto-ignition risk and is safe in ports above 775°/ 412°C. Less smoke and no residue.
- VersaSonic®: is the most versatile ultrasonic couplant with two viscosities; optimizing inspections from high temperature to working in mud and snow (-10° to 750°F / -23° to 371°C).
- AUT Fluids: Echo has the broadest line of AUT fluids with several viscosities to optimize pumpability and reduce run-off.
If you haven’t tried our couplants, contact us today to speak with one of our experts. Complementary samples available.
During phased array testing, element dropout can be a problem. Common causes include dead elements in the transducer or a failure of the wedge-to-transducer or wedge-to-inspection-part coupling.
Let’s look at each of these coupling failures in detail before offering some solutions for each of these PA testing issues.
Wedge-to-transducer coupling failure is often partial and typically involves multiple adjacent elements. While minimal phased array element dropout at the edges of the array can often be tolerated, failure of transducer coupling where multiple adjacent elements are not coupled into the wedge, particularly away from the array edge, will impact inspection quality, reproducibility and reliability. This dropout is often not detected, and the technician continues scanning unaware of increased side lobes (or grating lobes) and altered beam steering characteristics.
The couplant used between the transducer and the wedge is critical to reproducible inspections. When the couplant is exposed to water or to the couplant used on the parts being inspected, leaching of the wedge couplant can occur. Heating and cooling can cause thermal expansion and contraction of the couplant, tearing apart sections of the wedge coupling film. Some wedge couplants can partially evaporate over time, resulting in progressive failure of the coupling film.
To prevent problems with transducer-to-wedge coupling in phased array inspections, you need a wedge couplant with the following properties:
- impervious to water and other couplants, to prevent leaching of the wedge couplant around the perimeter;
- strong film former, to prevent isolated air pockets due to localized coupling film separation;
- high viscosity (over 3,000 cps), to ensure uniform coating and thickness independent of the surface and the mating characteristics of the wedge and transducer;
- resistant to evaporation or vaporization over the temperature range in which the PA transducer will be used and stored;
- thermal stability to prevent expansion and then contraction of the coupling film, resulting in film separation;
- compatibility with materials used in phased array transducer construction and wedge materials;
- long lasting so that it does not need to be replaced for the life of the wedge; and
- promotes easy replacement of wedges, without sticking or bonding between wedge and transducer, regardless of storage conditions.
Wedge-to-test-object coupling failure caused by couplant film failure results in acoustic reflection into the wedge, generating false reflections and noise. Couplant film failures of this nature are usually partial and continually change in location and configuration as the transducer assembly moves.
Failure of the couplant between the wedge and the test piece is most often due to low strength and fragile film formation. One example is gel couplants of the acrylic polymer (Carbopol) type. These polymers, which were originally developed for the hairstyling industry, have weak film-forming characteristics and are subject to collapse of the coupling film when exposed to corrosion or marine salts.
Couplants that have a water component in the formulation also may have weak film-forming properties. While water solubility is a desired feature in many applications, water incorporated into the couplant formulation serves mainly to lower cost. It does not promote coupling film strength. Couplants that contain water also can be subject to film failures from vaporization or the formation of ice crystals on the test site.
Echo Ultrasonics offers solutions to problems with both wedge coupling and inspection-object coupling in phased array inspections.
- Forever Wedge Couplant addresses failure in coupling the PA transducer to the wedge. Forever Wedge Couplant will remain in place for the life of the wedge and is impervious to water, other couplants, heat, thermal expansion and contraction, and evaporation. It also can overcome mechanical issues, such as mating or surface roughness of the wedge-to-transducer interface.
- EchoPure is a water-free couplant that provides a strong, uniform coupling film that eliminates dry spots between the wedge and the part being inspected. EchoPure also meets the water-free-couplant requirements for inspecting P91 steel prior to heat treatment.
Free samples of EchoPure and Forever Wedge Couplant are available for your evaluation.
Thanks to everyone who visited with us at ASNT in Nashville.
Couplant sample requests are being entered and we will be in touch soon. We had many discussions regarding the use and success of EchoPure for Phased Array inspections. EchoPure is the solution for phased array element drop out and the resulting difficulty in reproducing flaw indication. The water-free formulation and strong coupling film of EchoPure provides a continuous film between the part and the transducer and resists “air gap puddling” which is common with couplants containing water.
EchoPure is an excellent ultrasonic couplant for inspecting hot welds before they cool or UT inspection in the hot sun.
EchoPure is also ideal for boiler inspections as it is salt resistant and slow to dry.
EchoPure LV has been extremely popular for tank inspections.
EchoPure contains no water, but is completely water soluble and water-removable.
EchoPure is non-toxic and safe for food processing equipment.
The operating range of EchoPure is -60 to 350°F.
EchoPure is available in four viscosities (fluid, low, medium and high).
Request your free sample today.