Table 4.

Emerging commercial Pipeline Inspection Gauge (PIG) technologies.

PIG Type	Technical Function	Image
GP	To collect information relating to the physical shape or geometry of pipelines	ROGEO Untouched GP. Reprinted from ref. [110].
MFL	Suitable for the pipe diameter range of 76–1422 mm and integrated for super high resolution to identify and size significant corrosion	GE PII MagneScan SHR MFL [4] (Reproduced with permission Elsevier)
UT	Special configuration unites metal loss and cracks detection, available for pipeline size 20″ and above	NDT-GLOBAL LineExplorer UCM. Reprinted from ref. [110]
EMAT	High reliability inspection and accurate continuous measurement of critical crack anomalies, coating disbandment	ROSEN RoDD EMAT [119,126]. Reprinted from ref. [119]
EC	Integrated with deflection sensors that enable for simultaneous measurement of internal pipe profile and metal loss	ROSEN EC [110,127]. Reprinted from ref. [110]
	Has electromagnetic sensors embedded into the polyurethane. The array of electromagnetic sensors detects shallow internal corrosion and fatigue cracking (SICC) in dry gas or multiphase pipelines	I2I eddy current Pioneer (Reprinted with permission from ref. [120]. Copyright 2021 I2I Pipelines.)
	MWM-Array technology is used for high-resolution imaging of internal corrosion, internal initiated and relative stresses can be provided	JENTEK ILI Tool [121] (Reproduced with permission ASME Press)
Integrated Function	enable multiple data acquisitions for pipeline integrity with a single run, reduces inspection costs and workload	TDW (DEF+SMFL+MFL+LFM+EMAT). Reprinted from ref. [110]
Specific Function	Cathode protection current measurement ILI system which can capture data that verifies the effectiveness of Cathode Protection	Baker Hughes CPCM ™. Reprinted from ref. [110]
MEC	Inspection of compound pipelines with stainless steel and carbon steel in two layers	Shenyang Academy of Instrumentation Science MEC Tool