Reflecting on 25 years of gas line safety
Q & A with Fred Young, transmission manager for the Vancouver gas line and 37-year FortisBC veteran
Our existing natural gas gas line serving Squamish, the Sunshine Coast and Vancouver Island has operated safely and without incident for over 25 years. From helicopter inspections to internal line inspection, Fred Young shares the inside story of the tools and techniques used to ensure gas line safety.
The proposed Eagle Mountain-Woodfibre Gas Pipeline Expansion project will deliver natural gas to the Woodfibre LNG facility located southwest of Squamish. The expansion will be built using welded steel and field bends that are highly resistant to seismic motion (the earth moving). Qualified professionals will conduct geotechnical studies to identify areas that may be prone to movement during earthquakes so that we can either avoid these areas, or take precautionary measures.
Gas Line Construction Safety
Was seismic activity considered when the original gas line was built?
In my opinion, the quality of engineering that went into the routing, depth of cover and protective measures on the system are why we’ve operated without incident for 25 years. Our system runs through some very geologically active valleys that can bring debris flow over top of the gas line. At each of these locations, measures were taken to lessen such occurrences, which have resulted in minimal service interruptions.
Gas Line Monitoring Safety
How are gas lines monitored and how do you know everything is running smoothly?
Gas line pressure is monitored 24 hours a day at our system control centre.
We have a series of automated line break valves situated in key areas along the transmission system that monitor static pressure and pressure changes. If the gas line pressure suddenly rises or drops, the line break valve will close. This information is sent to our department so that a technician can respond.
Why are helicopter inspections of the gas line right-of-way conducted?
A crew of four technicians oversees approximately 650 kilometers of gas line over very rugged and, in some cases, very inaccessible terrain. Techs are on the lookout for geological or hydrological activity such as washouts and third party activity. They document what they see so a ground patrol can follow up.
Tell me about the electronic inspection tools that travel inside the gas line to search for defects that can’t be detected from the surface.
The internal line inspection process is a variety of complex systems used to check gas line integrity. One system we use is the Magnetic Flux Loss, which analyzes a magnetic field placed around the gas line. The data we receive tells us about the gas line's wall thickness, metal loss, joint length etc.
Is there some way to prevent metal loss and retain the gas line’s wall thickness?
FortisBC has a Corrosion Department responsible for reducing the effects of metal loss due to natural metal breakdown. This department sets the standards for coating products that are used on the gas line and also the cathodic protection system which combats the natural metal breakdown.
What is the first line of defense in monitoring gas line safety?
The work the technicians do on the ground can’t be replaced. Techs are always monitoring the depth of cover over the gas line at creek crossings and other locations. FortisBC transmission employees take ownership in the gas line and operate this system with pride. This type of attitude goes a long way to keep the system running safely.
Was this helpful?