GE C-PT, Руководство по установке

Страница: 11 / 72

C-PT Ultrasonic Flow Transducer Installation Guide 3
4. Couplants
GE supplies an ultrasonic couplant for your C-PT installation. The purpose of the couplant is to provide reliable
transmission of ultrasound between two adjacent solid surfaces. Generally speaking, couplants perform this task by
excluding air from between the adjacent surfaces. Accordingly, the C-PT transducers should be pressed tightly against
the pipe, using hand pressure on the set screw to squeeze the couplant to as thin a film as practical for the given pipe
surface.
The most commonly used couplants in ultrasonic testing are ordinarily satisfactory for any short-term clamp-on
flowmeter application. These couplants include, in general order of preference: gels, grease, propylene glycol, oil,
glycerine, and water. Long-term couplants include grease, epoxy adhesive, and solid rubber-like sheet couplant.
GE provides couplants for both permanent and temporary use as well as for high- and low-temperature applications.
For long-term installations, make sure the couplant does not dry or run out.
Standard couplants supplied from GE are listed in Table 1.
Table 1: Couplants
Part No. Type Temp. Range Use
CPL-1 Standard –40 to 149°F (–40 to 65°C) Semi-Permanent
CPL-2 High/Low Temperature –256 to 500°F (–160 to 260°C) Semi-Permanent
CPL-3 Portable –4 to 140°F (–20 to 60°C) Temporary
CPL-4 Special As Required * Difficult Applications
CPL-7 Epoxy 14 to 122°F (–10 to 50°C) Permanent
CPL-8 Solid Sheet –40 to 446°F (–40 to 130°C) Permanent
* Installations involving hotter or colder temperatures than listed above, may require special
couplants. Consult GE for these applications.