RadioBanter - View Single Post - AD5TH Tower

July 18th 05, 07:29 AM

On Fri, 15 Jul 2005 10:16:02 -0500, (Richard
Harrison) wrote:

Another example is found in high pressurre gas pipelines. Their internal
pressure cycles and this tends to enlarge microscopic cracks, if any, in
the pipe. Pipes are hydrostatically tested before placed in service (no
energy storage in water as it is incompressible) so a pipe blow out of
water won`t likely hurt a bystander. After the pipe is put in service it
is retested each year.

A major problem for pipelines are where both corrision and cracks are
within limits but close to each other. The pipeline folks have been
analyzing and fixing those for over a decade now.

Retesting is not done by pressure, as far as I know, but by sending
"pigs" down the line to analyze the pipeline.

Tony