Pipeline Engineering Interview Questions

The following section will list some interview questions asked in the different interviews for a Pipeline Engineer Position. Readers are requested to provide the answers in the comment section which I will add in the main section in due course.

1. Explain the basis of pipeline hydraulics and how will differentiate the gas and crude oil pipeline that is which method will perform to do the calculation.
2. What are all the softwares available in the market to perform pipeline hydraulics and how will you check the input and output?
3. What are the criteria for route selection of gas and crude oil pipelines?
4. For the sloped pipeline, how to fill the water during the hydrostatic test and why?
5. Explain the hydrostatic test pressure with respect to ASME B 31.8/31.4. How do they arrive the 90% of SMYS and what is the basis?
6. Explain about one pipeline project lifecycle, starting from concept, FEED, Detail Design, and construction (Sequence).
7. What is the difference between PSL-1 and PSL-2, what are all the tests involved during manufacturing?
8. What is the procedure/sequence of linepipe manufacturing?
9. What % of line pipe is radiographically tested during manufacturing?
10. Spiral welding can be used in oil and gas, if No, why?
11. Wadi crossing types and construction methods.
12. Isolation joints internal and external coating requirements and temperature ranges.
13. Draw and explain the pig launcher and receiver sequence.
14. Pipeline Hydrotest procedure.
15. What are the steps involved in pre-commissioning of the pipeline?
16. Steps involved in pipeline construction.
17. Distance between pipelines in the same trench and separate trench.
18. What are the disadvantages of the pipelines in the same trench?
19. Distance between the OHL line and the pipeline.
20. GRE pipelines – explain the advantages and disadvantages compared to carbon steel pipelines.

1. Specify Internal and external coating types with temperature limitations.
2. What is the reason for choosing the DSS pipeline with respect to fluid properties?
3. What are all the testing requirements for SOUR service pipeline items?
4. What is PWHT and what is the limitation of thickness with respect to international codes?
5. What is the philosophy of Pipeline supporting and anchor points for looped lines?
6. What is Cathodic Protection? What are the Anodic materials used in the pipeline CP systems?
7. What are the calculations performed during Hot tap design?
8. Draw a Block Valve Station for gas and crude oil pipelines separately.
9. What is the MPT requirement for Golden Joints?
10. Explain the GRE wall thickness calculation basis and steps.
11. Explain DPE and SPE on the ball valve.
12. For high sour service, how you will provide grease point and sealant injection?
13. During PE lining Wall Thickness calculation, what are the important factors you considered?
14. During PE lining pulling how many bends are allowed?
15. 3LPE /3LPP temperature minimum and maximum.
16. Explain uni-directional and bi-directional pig traps.
17. How you will consider corrosion allowance in pipeline systems?
18. Explain upheaval bucking and how to avoid it.
19. Briefly explain the pipeline routing considerations for Greenfield and Brownfield: Start with design and end with commissioning.
20. Briefly explain the gauging.

1. What is the double piston effect on pipeline ball valves?
2. Explain upheaval buckling and its calculation methodology.
3. What are Location classes with respect to ASME B 31.8 and ASME B31.4?
4. Explain road crossing calculation methodology.
5. Explain the Isolation Joint working principle.
6. Specify the Types of pigs and their applications.
7. What HIPPS valves? Explain about SIL level.
8. Difference between transition and pup piece.
9. What are all the required parameters for hydraulic analysis? As a pipeline engineer, what are the inputs needed to perform hydraulic analysis?
10. What is your understanding of Environmental Impact Assessment (EIA)?
11. What are the different types of tests involved in GRE pipes?
12. Types of pigs and usage. Length of the intelligent pigs and MFL tools.
13. Explain cathodic protection and Types of cathodic protection – in general.
14. As a pipeline engineer, what do you know about line sizing?
15. What is pipeline equivalent stress? What are all the stresses generated in a pipeline?
16. How bending radius will affect the Pipeline Wall Thickness Calculation?
17. What are the proximity distances and no. of buildings according to the location class?
18. Where are Isolation joints to be installed and why? In IJ above 50 bar, what is the precaution?
19. Draw the pig trap and explain the pigging procedure.
20. Explain about CMA fittings and location, why?

1. Compare a BVS requirement with EIA.
2. What are the differences between restrained and un-restrained pipelines?
3. What are the criteria for expansion loops for un-restrained pipelines? During A/G pipeline design how expansion loops will be fixed?
4. What are the types of supports used for pig traps and why?
5. Tell about allowable displacement values and if exceed the limit what are the other considerations to be taken care of to have a flexible pipeline system during design.
6. What is Carbon Equivalent (CE) for line pipe and split tees? If two different CE pipes are needed to weld, which CE value has to be considered for qualification?
7. DWTT and CVN tests – Explain.
8. Explain the minimum branch sizes on pipelines.
9. Golden weld joints – explain what tests need to be performed for golden joints.
10. External coating types and temperature range.
11. Velocity accepted during the design for liquids and gas?
12. During End closure design what are the safety devices we have to consider?
13. During the design of pipeline design life, what are the factors to be considered?
14. PWHT requirement on the pipelines.
15. How you will protect your pipeline and flowline: explain from the well to manifold and manifold to the station.
16. Explain the pipeline design of the high temperature and pressure.
17. What are the major differences between ASME B31.4 and ASME B31.8?
18. A pipeline carries a fluid having a temperature of 250 Degrees C. Which ASME code will be used to design that pipeline?