Our Integrity Management Program is comprised of three main components:
1. Prevention - protecting piping and
from conditions that may lead to integrity concerns;
Ultrasonic Inspection of the pipe wall.
The Integrity Programs will focus on risk control in the following areas:
Facilities near high consequence areas;
A. Integrity Inspections
Field staff prepares a "smart pig" for launch.
Engineering Assessment of Inspection Data
After gathering data, our employees work with experts to analyze and diagnose pipeline anomalies. Mitigation and repair plans are developed and implemented specific to the concerns identified on each inspected pipeline.
Our in-line inspection (ILI) program began in 1997. By the end of 2005, 3,457 km of pipeline has been inspected with ILI. By the end of 2007, TransGas will have inspected major system pipelines representing approximately 25% of our pipeline network.
Also, considerable amount of inspections are conducted on station piping and pressure vessels and this activity will increase as new programs are developed.
To date, approximately 85% of the total TransGas operational pressure vessels have been visually inspected.
B. Stress Corrosion Cracking
Stress corrosion cracking (SCC) is cracking arising from the combined actions of stress in the pipe steel, a corrosive environment around the pipe and susceptible pipeline material. Under specific conditions, what starts as a hairline crack on the outside of the pipe can progress into a cluster or colony of cracks. These cracks may join together and deepen to the point where they may grow through the entire wall thickness. TransGas has had some encounters with minor SCC on our system that were immediately remedied.
Inspectors document the pipe surface conditions.
C. Cathodic Protection
TransGas on a regular basis perform transmission leak surveyand encroachment patrols. Employing local contractors, we perform walking, ATV, aircraft and helicopter patrols of our facilities throughout the province to inspect, identify and report activities that may affect the safe operation of our system. A possible leak is marked during a routine aircraft survey and further investigated by TransGas personnel.
Over time, the implementation of modern technology on pipeline construction and maintenance, combined with our Integrity Program, has dramatically reduced leaks on the system.
If you are planning excavation work, please call Sask1stCall TransGas’ annual average for the past 10 years is 2.2 reported pipeline hits per year.
TransGas recorded 0.14 pipeline contacts for every 1,000 km of pipeline in 2005.