XI. Translate the following sentences into Russian
1. Presence of solids in gas results in abrasive deterioration of pipes and equipment, and plugging of instrumentation.
2. Presence of water vapors in gas results in corrosion of pipelines and equipment, and also formation of hydrates in pipelines.
3. Hydrogen sulfide is harmful and toxic gas also capable to cause pipe corrosion.
4. Carbon dioxide is harmful because it decreases gas combustion heat, and also leads to equipment corrosion.
5. Gas processing plants perform gas reception, metering and treatment including separation and dehydration of gas for processing.
6. Unstable natural gasoline is separated into stable natural gasoline and individual technically clean hydrocarbons, such as propane, butanes, and pentanes.
7. Central treatment facilities perform gas treatment to prepare it for transportation.
8. Export gas lines with high throughput use centrifugal injection pumps with gas turbine drive or electric drive.
9. Gas distribution stations are built in the end of each export gas line or its branch.
10. Gas must be also treated and given sharp specific odor in order to identify leaks, the process is called gas odorization.
XII. Give short answers to the questions
1. Is natural gas recovered from wells?
2. Is hydrogen sulfide harmful and toxic gas?
3. Can gas be transported to consumers in bottles by road railway?
4. Do central treatment facilities perform gas treatment to prepare it for transportation?
5. Are underground gas storages used to compensate gas consumption during peak and low consumption periods?
XIII. Give a short rendering of the text, using the words and phrases of the exercise I
XIV. Project (in written form)
Discuss the idea of gas processing.
XV. Make an abstract of the text
Direct current voltage gradient
Direct Current Voltage Gradient (DCVG) uses the signal information of the lateral and longitudinal surface voltage gradients of an externally applied DC current on the pipe to locate coating flaws. The theoretical voltage gradient at a single coating flaw (valid for both DCVG and ACVG) could be described by the radial equal potential gradient lines in an ideal situation (with uniform soil resistivity). Generally, with current concentrating on a single coating flaw, it flows through the soil, producing a voltage drop that is proportional to the soil resistivity and distance.
The DC current can be applied through the existing CP system anode ground bed (if remote from the pipeline) and rectifier, or with a temporary CP system. The current is interrupted (by turning on and off) in a continuous cycle that results in an oscillating gradient field. Specialized equipment is used to measure the magnitude of the voltage gradient cycle with probes contacting the ground surface.
The surveyor walks directly over the pipeline in the direction away from the location of the signal connection using soil contact probes in a manner similar to walking sticks. The surveyor places the pins firmly in the ground at approximately five-foot spacing and notes the swing signal strength and direction. As a coating flaw is approached, the swing signal amplitude will increase and then reverse direction after the coating flaw is crossed.
When a reversal in signal direction is noticed, the surveyor retraces until the signal is null. The center of the pin span is the location of the indicated coating flaw. The surveyor then changes the direction of the pin span, and the side drain measurement (perpendicular to the pipeline) is then performed on both sides of the pipeline. The side potential gradient readings are used to calculate the relative size of the indicated coating flaw along with the signal attenuation from the connection point.
UNIT X
Pipeline valves
Lead in: Look at the pictures and comment them
