MIL-HDBK-1022A
Prior to selecting a treatment method, review state
and local environmental regulations and consult the facility
for acceptable alternatives and permits required for on-site
treatment and disposal.
12.11
LIQUEFIED PETROLEUM GAS (LPG) FACILITIES. When
rehabilitating an LPG facility, back weld (seal weld) all
existing threaded piping.
12.12
PIPELINE INSPECTION
12.12.1
Inspection. Conduct pipeline inspections in
accordance with API 570.
12.12.2
Smart Pigging. To determine if or how a pipeline
requires rehabilitation, information on the pipeline's
structural integrity is essential. One method to survey the
condition of the pipeline is to use smart pigs.
12.12.2.1 General. A "smart" or "intelligent" pig is one of a
variety of instrumented tools using one or more physical or
electro-mechanical principles for recording and measuring
information for positioning and relative severity of anomalies
in a pipeline. Smart pigs can detect cracks, metal loss, and
curvature/bends. Other types available can map and profile
pipe, detect leaks, perform photographic inspection, and
sample product. Use of smart pigs may require modifying the
pipeline to increase the radius of sharp elbows and eliminate
obstructions caused by valves that are not full port type.
12.12.2.2 Types. The three basic types of smart pigs are
ultrasonic, magnetic flux leakage (MFL), and eddy current.
Ultrasonic, MFL, and eddy current pigs can be used in liquid
pipelines. An alternative form of ultrasonic inspection is an
electromagnetic acoustic transducer (EMAT). An EMAT can be
used in either a liquid or gas pipeline. MFL can also be used
in gas pipelines. Prior to choosing a smart pig, consider
expected results, cost of various options, and expected
pipeline condition.
12.13
CHECKLIST. The following is a checklist of items to
be considered in a major rehabilitation.
a) Aboveground storage tank rehabilitation
206
Previous Page
