Retrospective Evaluation of Cured-in-Place Pipe - (NEPIS)(EPA ...

Mean thickness values for each control specimen are shown in Table B-2. From the data, it can be seen
that the ultrasonic gauge works well when the specimen is well impregnated in resin (2.0 lb/ft or higher
resin content), but does not provide a reading when the resin content falls to 1.5 lb/ft.
Resin
Content
lb/ft
Slide
Calipers
(in.)
Table B-2: Measured Thickness of the Controlled Specimens
Quik POX Quik PE Reichhold
Ultrasonic
(in.)
Slide
Calipers
(in.)
B-3
Ultrasonic
(in.)
Slide
Calipers
(in.)
Ultrasonic
(in.)
2.50 0.234 0.234 0.269 0.268 0.228 0.229
2.00 0.242 0.241 0.240 0.237 0.201 0.198
1.50 0.217 N/A 0.239 N/A 0.196 N/A
N/A = Reading not available
B.3 Other Specimens
The ultrasonic gauge did not provide readings when used on a felt sample. This is attributed to the
absorption of acoustic energy by the material. The device also did not provide a reading when used on an
improperly cured liner, as shown in Figure B-4.
Figure B-4. Ultrasonic Thickness Measurements on Improperly Cured Liner
The device worked well in the case of a PVC liner. A SDR35 PVC pipe was used. When measured with
a slide calipers, average thickness value was 0.187". Using the ultrasonic device, the thickness found was
0.182-in. to 0.183-in., as shown in Figure B-5.
Figure B-5. Ultrasonic Instrument Used to Measure Thickness of PVC Pipe