Chesapeake uses special care to ensure that pipelines are built to last. Full interior inspections of the existing pipeline are conducted to check for any inconsistencies in the pipeline wall. Patrols of the pipeline routes are inspected by foot, vehicle or airplane to regularly check the surface above the pipeline.
Pipeline cleaning and inspection tools called pigs, which can be inserted into the line at locations called pig traps, sweep through the pipeline gathering any residual moisture contained in the gas and removing it from the line. Smart pigs have the ability to accurately detect and locate any pipeline anomalies so that measures may be taken to correct the situation.
“Smart” PIGs have the capability to accurately detect and locate any pipeline anomalies.
Another maintenance method to prevent the occurrence of corrosion involves the use of cathodic protection. This common technique for inhibiting any corrosive effect on metal uses a low-voltage electrical current to keep water from accumulating in the pipe. Cathodic protection systems are utilized in many industries to protect fuel pipelines and storage tanks, ships, offshore oil platforms and onshore oil-well casings.
Gathering lines have distinct differences from the distribution lines that bring natural gas into people’s homes and businesses. A chemical odorant is typically only added to natural gas in distribution lines, so that when a gas leak is confined within a structure where it cannot escape, the odor signals the accumulation of the gas.
In contrast, gathering lines feature extensive control measures to detect leaks such as the continual monitoring of any drop in pressure, regular pipeline inspections and a heavy pipe design that far outweighs those found in distribution lines. These safety measures make the addition of odorant unnecessary at this stage of the pipeline process.
It’s important to remember that as the natural gas travels through the gathering lines, it contains water and other impurities which might mask, dilute, or otherwise affect the consistency of odorization. Adding an odorant to natural gas too early in the production process can also cause equipment problems for industrial users down the line and can make natural gas unsuitable for some market uses.
A routine inspection of the pipeline valves at the 4th Street site near downtown Fort Worth.
Q. What is MAOP?
A. MAOP is an acronym for Maximum Allowable Operating Pressure. It is the maximum internal pressure that is permitted in the operation of a pipeline, as defined by the Code of Federal Regulations Title 49 Part 192. The MAOP determined after considering multiple factors, such as pipe material, grade, pressure tests, operation, population density, and maintenance history.
MAOP is important because it is the maximum amount of pressure that the pipe is designed to hold. If the MAOP is exceeded at any time, the operator must report that event to the Railroad Commission of Texas.
Q. Should I be more concerned about a high pressure line than a low pressure line?
A. Not if the line is designed and installed properly. Federal safety standards take the line pressure into account as part of the pipeline design. These standards are more stringent as the pipeline’s designed MAOP crosses a certain threshold. In the unlikely event that a high pressure line incurs a problem, it usually occurs in such a manner that the situation is immediately apparent due to the constant monitoring of the pressure in the lines.