Piping Engineer's Q&A
1. Can you explain in detail three or more major differences between code ANSI B31.1 and code ANSI B31.3?
There is only one major difference between the two, B31.1 is for power piping and B31.3 is for refinery/chemical plant piping.
2. There is a power plant inside a process refinery.Where exactly the ANSI B31.1 & ANSI B31.3 scope break occurs?
Based on my experience there were two cases. case #1, B31.1 stopped at the power plant unit block valves, thus all piping inside the power plant was B31.1. case #2, B31.1 stopped at the equipment (boiler) isolation block valves and then all other piping was B31.3. This is normally the choice of the owner/operator/client.
3. Which of the following piping system is more health hazardous.
A) Fuel oil piping
B) Process piping with caustic
C) Process piping with HF acid
D) Sulphuric acid piping
Answer:C) Process piping with HF acid
4. There is a steam piping with low pocket, but without steam trap. What will be the worst consequence of this layout?
There will be a buildup of condensate to the point that a slug will be pushed by the steam flow. This slug of condensate will cause "water hammer" and could rip the piping apart.
5. In what circumstance, the reducer of a pump suction piping will be in bottom flat position. Explain why the reducer should be so.
When reducers are placed in pipe rack they are generally bottom side flat to maintain BOP to facilitate supporting.
6. A P&ID shows a spec break (at flange) between carbon steel & stainless steel specification. What additional arrangements you have to make for that dissimilar material flange joint?
Use the gasket and bolts from the SS spec.
7. A stainless steel piping specification mentions galvanized carbons steel bolts. What is your first reaction to this and how do you rectify it?
If that is what the spec call for then, that is what I am supposed to use. However, I would ask the Piping Material Engineer(PME) why he/she specified galvanized bolts.
8. How many types of piping specialty items do you know? Why is it called a piping special? Why not we include them in standard piping specification.
I could possibly count 50 or more depending on the PME and how the piping material specs were developed. They are called them SP items because they are not written into the normal piping material (line class) specifications. They are not included because they are normally of limited use, purchased from a limited product line vendor and are often after thoughts.
9. Draw a typical steam trap station layout and explain why the existence of a by-pass line around the trap is not a good idea, when the condensate is returning to a condensate header?
(No drawing) It is not advisable to have a bypass around a steam trap because the block valve could be left open and defeat the purpose of the trap.
10. Explain what is a "Double block & bleed" valve?Why we need a bleed valve? When do we use this?
The primary purpose of a "Double block & bleed" is safety,but it is not failed safe. The next better "safety" set-up would be double block valve with a spec blind between the valves. The higher level of safety would be double block valves with a removable spool for absolute isolation.
11. In a typical tie-in where should the spectacle blind be inserted? a) after blocking valve and towards existing plant b) before blocking valve and towards new plant. Explain why.
The spec blind has be placed on the unit side of the unit block valves. This placement allows for the closing of the unit isolation block valve, the unit side is depressurized and drained, then the spec blind can be installed for isolation of the unit.
12. "Stress Intensification Factor (SIF)"Where do we use this? Explain this term. How many types of these SIF's exist?
Stress Intensification Factor (SIF) is a multiplier on nominal stress for typically bend and intersection components so that the effect of geometry and welding can be considered in a beam analysis. Stress Intensification Factors has form the basis of most stress analysis of piping systems. As for the quantity, ask a stress engineer.
13. When all design parameters are the same, whose thermal expansion is higher among the following?
A) Carbon Steel
B) Stainless Steel
C) Duplex steel
D) Cast Iron
E) Galvanized carbon steel
Answer: B) Stainless steel
14) In a hose station the hose couplings used for water, air& steam should be different type. Do you agree? Explain your view.
I agree. If they are all the same, then the hoses can be connected to the wrong services and could result in the injury of an operator (e.g. thinking the hose is connected to water when it is connected to steam).
15. What is your view on the usage of metallic expansion joints? When they become necessary and when they could be avoided?
I do everything I can as a piping designer to avoid the use of all types of expansion joints. Expansion joints are always the weakest point in any system where they are used.
16. A water-cooler heat exchanger, located on a 20m high structural platform. Water header is located u/g. What precaution do you take, in case of pressure loss in cooling water header?
I do not understand this question it does not appear to be a piping issue. I would assume that the cooling water system has a (loss of) pressure sensor and the plant shut-down alarms and sequence would be activated.
17. In what orders do you arrange the pipes in the pipe rack and why? How much % of area should be reserved for future expansion? Specify a range.
The largest hottest lines on the outside edge of the pipe rack working in with cooler lines in towards the middle of the rack. This allows the longer loop legs as you lay the loops back over the other lines to the other side of the rack and back. The lower temperature loops would be "nested" inside the larger, hotter loops.
"Future rack space" is normally at the direction of the client. It may be anything from 0% to as much as 25%.
18. When a utility line (like condensate or water, etc.) is connected permanently to a process piping what precaution we have to take to avoid cross contamination?
Option #1, Double blocks valve with a drop-out spool.
Option #2, Double blocks valve with a spec blind
Option #3, Double blocks valve with a bleed valve.
19. A air fin cooler (two air coolers with ech having two inlet nozzles) needs a typical piping arrangement. How many types of piping arrangements is possible.
There are a number of ways to pipe a Fin-Fan cooler depending on what the P&ID call for.
piping knowledge Test
Can you explain the difference between seamless and welded pipes?
- Seamless pipes are made from a single piece of metal, while welded pipes are created by welding multiple pieces together. Seamless pipes are generally stronger and more expensive, while welded pipes are suitable for lower-pressure applications.
What is the purpose of a pipe flange?
- A pipe flange is used to connect pipes, valves, and other equipment to form a piping system. It provides a convenient method for assembly and disassembly and allows for easy maintenance and inspection.
What are the common materials used for piping in industrial applications?
- Common materials for industrial piping include carbon steel, stainless steel, copper, PVC, and various types of alloys. The choice of material depends on factors like the fluid being transported, temperature, and pressure.
Explain what a P&ID (Piping and Instrumentation Diagram) is and its importance.
- A P&ID is a graphical representation of the process and instrumentation of a piping system. It shows the interconnected components, pipes, valves, instruments, and their interactions. It's crucial for design, construction, and maintenance of the system.
What is the purpose of pipe supports in a piping system?
- Pipe supports are used to maintain the position of pipes and prevent sagging, stress, and vibration. They ensure that pipes are properly aligned and supported, contributing to the overall integrity of the system.
Can you describe the terms "NPS" and "DN" in relation to pipes?
- NPS (Nominal Pipe Size) is a North American standard for specifying pipe sizes based on inches, while DN (Diameter Nominal) is an international standard based on millimeters. These standards help in selecting the right pipe for a specific application.
What is the purpose of hydrostatic testing in piping construction?
- Hydrostatic testing is done to verify the integrity of the piping system by pressurizing it with a liquid, typically water. It helps identify leaks, weaknesses, and ensures the system can withstand the intended pressure.
How do you calculate the flow rate of a fluid through a pipe?
- The flow rate (Q) is calculated using the formula: Q = A × V, where A is the cross-sectional area of the pipe and V is the velocity of the fluid.
What are the key considerations when designing a pipe routing layout in a plant?
- Factors to consider include safety, accessibility, thermal expansion, equipment compatibility, and avoiding obstacles. A well-designed layout should also optimize maintenance and minimize pressure drop.
Explain the terms "ASME B31.3" and "API 570" in the context of piping codes.
- ASME B31.3 is a widely recognized code that covers the design, construction, and maintenance of process piping in the chemical, petrochemical, and refining industries. API 570 is specific to inspection, repair, alteration, and rerating of in-service piping systems in the petrochemical and chemical industries.
Remember to tailor your answers to the specific job and its requirements, and provide examples from your experience where relevant.
piping engineering knowledge
Piping engineering is a specialized branch of engineering dealing with the design, layout, fabrication, and installation of piping systems. Piping systems are used to transport fluids and gases in a wide variety of industries, including oil and gas, petrochemical, power generation, and pharmaceutical.
Piping engineers must have a strong understanding of fluid mechanics, thermodynamics, materials science, and structural engineering. They must also be familiar with the various codes and standards that apply to piping design and construction.
Some of the key areas of piping engineering knowledge include:
- Piping system design: This includes determining the pipe size, material, and routing, as well as selecting the appropriate valves and fittings.
- Pipe stress analysis: This is used to ensure that the piping system can withstand the various loads that will be applied to it, such as internal pressure, thermal expansion, and external forces.
- Piping fabrication: This involves the cutting, welding, and bending of pipe to create the desired piping system layout.
- Piping installation: This includes the erection of the piping system in the field and connecting it to the various equipment and other piping systems.
In addition to the above, piping engineers must also be able to communicate effectively with other engineers, project managers, and contractors. They must also be able to troubleshoot problems and make quick decisions in the field.
Here are some specific examples of piping engineering knowledge:
- Types of pipe: Piping engineers must be familiar with the different types of pipe available, such as steel, stainless steel, copper, and plastic. They must also be able to select the appropriate type of pipe for the specific application, taking into account factors such as the fluid being transported, the operating pressure and temperature, and the corrosive environment.
- Pipe fittings: Piping engineers must also be familiar with the different types of pipe fittings available, such as elbows, tees, reducers, and flanges. They must be able to select the appropriate type of fitting for the specific application, taking into account factors such as the pipe size, material, and routing.
- Valves: Piping engineers must also be familiar with the different types of valves available, such as gate valves, globe valves, and check valves. They must be able to select the appropriate type of valve for the specific application, taking into account factors such as the fluid being transported, the operating pressure and temperature, and the flow control requirements.
- Pipe supports: Piping engineers must also be able to design and select the appropriate pipe supports to ensure that the piping system is adequately supported and does not sag or vibrate.
- Piping insulation: Piping engineers must also be able to design and select the appropriate piping insulation to prevent heat loss or gain, as well as to protect the piping system from corrosion and other environmental hazards.
Piping engineering is a complex and challenging field, but it is also very rewarding. Piping engineers play a vital role in the design and construction of safe and reliable piping systems that are essential for many industries.
piping technical questions
Here are some piping technical questions and answers:
Question: What is the difference between a blind flange and a spectacle flange?
Answer: A blind flange is a flange with a solid face that is used to seal off the end of a pipe. A spectacle flange is a flange with a removable center section that allows for inspection or cleaning of the piping system.
Question: What are the different types of pipe stress?
Answer: The three main types of pipe stress are:
- Axial stress: This is the stress that occurs along the length of the pipe.
- Bending stress: This is the stress that occurs when the pipe is bent.
- Torsional stress: This is the stress that occurs when the pipe is twisted.
Question: What is the purpose of a pipe expansion joint?
Answer: A pipe expansion joint is a flexible device that is used to absorb thermal expansion and contraction of piping systems. This helps to prevent the piping system from buckling or breaking under thermal stress.
Question: What is the difference between a gate valve and a globe valve?
Answer: A gate valve has a gate that slides up and down across the flow path to open and close the valve. A globe valve has a plug that seats into a conical opening to open and close the valve. Gate valves are typically used for on/off service, while globe valves are typically used for throttling service.
Question: What is the purpose of a pipe support?
Answer: A pipe support is used to support the weight of the piping system and prevent it from sagging or vibrating. Pipe supports can be either fixed or movable, depending on the needs of the piping system.
Question: What is the difference between hard insulation and soft insulation?
Answer: Hard insulation is made from rigid materials, such as fiberglass or calcium silicate. Soft insulation is made from flexible materials, such as mineral wool or foam rubber. Hard insulation is typically used for high-temperature applications, while soft insulation is typically used for low-temperature applications.
I hope this answers some of your piping technical questions. Please let me know if you have any other questions.
Piping Engineer's Knowledge
A Piping Engineer's Knowledge Q&A is a set of questions and answers designed to assess the expertise and qualifications of a candidate applying for a position as a Piping Engineer or a related role in the field of piping and pipeline systems. Piping Engineers are responsible for the design, analysis, and maintenance of piping systems in various industries, such as petrochemical, oil and gas, power generation, and manufacturing. Here is a description of the purpose and content of a Piping Engineer's Knowledge Q&A:
Purpose:
- The purpose of this Q&A is to evaluate a candidate's technical knowledge, problem-solving abilities, and practical experience in the field of piping engineering.
- It helps the hiring manager or interviewer determine if the candidate possesses the necessary skills to handle tasks related to piping design, stress analysis, material selection, and adherence to industry standards and codes.
Content: A Piping Engineer's Knowledge Q&A typically covers a wide range of topics, including but not limited to:
Piping Fundamentals: Questions on basic concepts like pipe materials, fittings, flanges, and valves, as well as the differences between various types of pipes (e.g., seamless vs. welded).
Piping Codes and Standards: Questions related to industry-specific codes and standards, such as ASME B31.3 for process piping and API 570 for in-service inspection.
Design and Layout: Questions about pipe routing, plant layout considerations, and how to design piping systems for safety, efficiency, and ease of maintenance.
Stress Analysis: Questions on stress analysis methods, including how to calculate pipe stress, select appropriate supports, and address thermal expansion issues.
Materials Selection: Questions about choosing the right materials for different applications based on factors like fluid type, temperature, and corrosion resistance.
Piping Software: Inquiries about the use of software tools like CAESAR II or AutoPIPE for stress analysis and AutoCAD for design.
Hydrostatic Testing: Questions on the purpose, procedure, and importance of hydrostatic testing in piping construction.
Project Management: Questions related to project management skills, including the ability to develop project schedules, budgets, and manage resources.
Environmental and Safety Regulations: Inquiries about knowledge of environmental regulations and safety protocols related to piping systems.
Problem-Solving Scenarios: Practical scenarios or case studies that test the candidate's ability to identify and solve complex piping-related problems.
Interview Format:
- The interview may include a mix of multiple-choice questions, technical questions that require in-depth answers, and problem-solving scenarios.
- Candidates may be asked to explain their thought process and provide examples from their past experience to demonstrate their qualifications.
A Piping Engineer's Knowledge Q&A is an essential part of the hiring process for positions in the field of piping engineering. It helps employers assess a candidate's technical competency and suitability for the role, ensuring they can design, analyze, and maintain piping systems effectively and in compliance with industry standards and regulations.