Echogel® 20 is an economical, basic-use couplant in medium-thick gel viscosity for ultrasonic inspections, like flaw detection/sizing and thickness gauging, where salt cake or metal corrosion salts are present. Echogel® 20 offers outstanding wetting capabilities and will quickly wet oily and dirty surfaces. It provides good corrosion inhibition and resists viscosity breakdown on salt-caked boilers and other corroded materials.
Echogel® 20 is available in the following sizes:
| Appearance: | Transparent gel |
| Color: | Light green |
| Comparative Viscosity*: | 5.5 |
| Actual Viscosity: | ~75,000 cps (LV #4 @ 6 rpm) |
| Long Velocity: | 1.55 cm/sec |
| Impedance: | 1.60 Mrayls |
| Acoustic Performance: | 50 |
| Silicone: | No |
| Glycerin: | No |
| Propylene Glycol: | Yes |
| Water Soluble: | Yes |
| Halogens: | < 50 ppm |
| Sulfur: | < 50 ppm |
| Temperature Range†: | 27° to 140°F (-3° to 60°C) |
| Storage Temperature: | 50° to 86°F (10° to 30°C) |
| Compatibility: | Most composites and metals |
* Subjective measure, 0–10 scale where 0 = water, 5 = medium gel, 10 = very thick paste.
† Couplant integrity and acoustic performance may decline beyond these temperature limits.
Apply a small amount of couplant to the transducer or inspection area before measurement.
Remove couplant immediately after inspection before the couplant dries with water rinse or a combination of water rinse and brushing. A film may form if the couplant is allowed to dry before removal. Remove film by pressure washing, wire brushing or immersing the part in water until the couplant rehydrates and can be washed or brushed off.
Store couplant in the original container. Do not freeze. Store out of direct sunlight. Keep container closed when not in use. Never put unused couplant back into the original storage container. If pumps or valves are used to dispense bulk couplant, wash them thoroughly between drums to avoid contaminating new product.