A rigid Strut is a dynamic restraint that is used specifically to reduce dynamic loads. They act as compression as well as tension element. Struts can also be a good alternative to the normal piping guide supports. The strut assembly consists of two rods joined by a structural steel member. They are selected from the vendor catalog considering the maximum load that has to be restrained.
Rigid Struts are used to provide a rigid connection between the piping and supporting structure. Using their pivot connection, rigid struts allow a small angular displacement in the range of (+/-) 7 degrees. This allows a little pipe thermal movement in a singular direction.
Refer to my earlier post “A Brief Description of Sway Brace, Strut and Snubber ” for the basics of working and the uses of Rigid Struts. This article will explain the step-by-step methods for modeling the Rigid strut using the software Caesar II.
Rigid Strut Modeling in Caesar II
The steps involved in Strut modeling are as follows:
1. Find out the direction in which restriction of movement is required (Assume X direction) and the location of the strut installation. For reducing thermal loads to be carried by rigid struts it is preferable to choose thermal null points if feasible.
2. Double-click on the restraints checkbox in the Caesar spreadsheet and model restraint X with a 0 mm gap and with no friction. Keep the stiffness K1 box blank.
3. Run Caesar Analysis and found out the force in that node.
4. Enter into any catalog (like C&P, Lisega, PTP, Anvil, Binder, etc) and select the appropriate rigid strut depending on that force (For your reference strut selection table has been reproduced in Fig. 1 from C&P Catalogue).
5. Obtain the stiffness value for the strut from the catalog and enter this value in restraint stiffness (K1) which u left blank in the initial stage.
6. Run the analysis to obtain results.
Fig. 1: Strut Selection Table from C&P Catalogue
Typical Application of Rigid Strut
Rigid Struts are used in Turbine and Compressor connected lines near the nozzle connections to take advantage of very little friction. Otherwise, struts can be used as a substitute for guide supports where the steel structure is not available for using standard guides.
Rigid Strut Ordering Information
Rigid struts are usually made of carbon steel. While selecting a rigid strut, its load-carrying capability must be checked from the manufacturer catalog. The important ordering information is:
Winterization Systems are required in refineries, petrochemical plants, and similar plants to protect equipment and piping against solidifying or coagulation of contents. Winterization in processing plants is normally achieved by using Steam Tracing, Steam Jacketing, Electrical Tracing, or Process Heating. This article will highlight the requirements for the basic design of the Winterization System.
Data Required for Winterization System Design
The data to be used for the design of winterization should be obtained from, but not limited to, the following documents ;
Winterization for process fluids shall be considered in all circumstances, appropriately for the fluids and local ambient conditions.
Winterization of water and steam condensate piping
The following table gives criteria for the requirement of winterization
Fig. 1: Criteria for Winterization Requirement
Winterization of Process Piping
Basic Principle:
Process piping where the pour point or solidifying point of the internal fluid is higher than the lowest ambient temperature shall be winterized. Unless otherwise specified, the fluid temperature shall be maintained above the solidifying point or at least 10°C above the pour point.
For liquid sulfur lines, steam jacket piping or electric heat tracing shall be applied to maintain the fluid temperature between 118 °C and 158°C.
For highly viscous fluids such as asphalt and bitumen, the fluid temperature shall be maintained, applying steam tracer piping or steam jacket piping, at temperatures exceeding the pour point +10°C or temperatures giving a kinetic viscosity of 300 CST (Allowable maximum viscosity during the use of centrifugal pumps) or lower, whichever is higher.
Appropriate measures to prevent fluids from temperature drop are taken for piping in which fluids are always flowing (on-stream) while the plant is being operated. The necessity of winterization, therefore, should be studied for the case where the plant stops operating.
Tank yards have many items of piping, in which fluids are not always flowing (not on-stream). Care should be taken on this point.
Winterization Requirements for Liquid Lines
The following winterization requirements should be applied to the liquid lines containing a fluid that has a higher pour point or solidifying point than the lowest ambient temperature.
(1) Winterization Philosophy for Lines always on-stream:
(a) Bare pipelines, in which the liquid is likely to coagulate within about 12 hours after the liquid stops flowing, should be hot insulated.
(b) Hot-insulated lines, in which the liquid is likely to coagulate within about 12 hours after the liquid stops flowing, should be steam traced, even though the liquid operating temperature is high.
(2) Winterization Philosophy for Lines not always on-stream (liquid-filled lines):
Every size of piping should be steam traced and hot insulated regardless of liquid temperatures.
The same criteria should also be applied to the following lines.
Vents and drains provided for the line should, in principle, be hot insulated; the requirement of steam tracing should be according to the line conditions.
(3) Winterization requirements for Lines not always on-stream (usually empty)
Such lines should be sloped so as not to form pockets and should also be provided with steam purge connections to completely empty the inside; otherwise, they should be only hot insulated.
(4) Other requirements for Winterization
Lines, in which highly viscous fluids such as heavy fuel oil flow, should be steam traced.
Caustic solution and amine solution lines should be steam traced when the freezing point of the solution is higher than the lowest ambient temperature.
Steam tracing of caustic and amine solution lines should be provided with insulating spacers to prevent alkali embrittlement.
Winterization Requirements for Vapor Lines Saturated with Steam
(1) Winterization for Lines always on-stream
(a) The upstream side of the lines of orifice plates or control valves, in which steam could possibly condense, should be hot insulated. The amount of condensate generated from the gas line has to be calculated by estimating the temperature drop and consequent partial pressure decrease of steam.
(b) Lines, in which freezing of condensed water is likely to cause trouble with continuous operation, should be steam traced.
(c) Lines are properly sloped so as not to accumulate condensate.
(d) Lines in which ice or hydrate can be possibly formed on depressuring should be steam traced.
(2) Winterization for Lines not always on-stream
Piping should preferably be free draining. The following items should be steam traced.
– Instruments (such as LG, LT, PG, and lead pipes of PT)
– Bypass lines for control valves
– Inlet line of a relief valve. In some cases, lines should only be hot insulated depending on pipe size and length, considering heat loss.
Winterization Requirements for Vapor Lines with Higher Dew Point Fluid
The following requirements should be applied to the vapor lines containing fluid that has a dew point higher than the lowest ambient temperature.
(1) Lines always on-stream
(a) The upstream side of the lines of orifice plates or control valves, in which vapor could possibly condense, should be hot insulated.
(b) Lines, in which condensate is likely to solidify or is corrosive, should be steam traced.
(c) Lines, in which condensate is likely to freeze or coagulate due to depressurization during shutdown operation, should be steam traced.
(d) Piping should preferably be free draining.
(e) Pockets where condensate accumulates, which may have adverse effects on the indications of instruments (such as PG, and lead pipes of PT), should be steam traced.
(f) Lines, which are likely to have adverse effects on continuous operation due to the condensing of the fluid, should be hot insulated.
(2) Lines not always on-stream
Fig. 2: Typical example of a steam tracing system
Winterization of Utility Piping
Water Piping-Main pipes should, in principle, be buried below the freezing depth. Aboveground piping or underground piping buried above the freezing depth should comply with the requirements of “Winterization of Process Piping”.
Described below are precautions, in particular, for water piping.
Piping of 2″ or less should be heat traced and hot insulated.
For piping of 3″ or larger, which is always on-stream, measures should be established to ensure that water flow is not interrupted, as far as possible. Along with this, temperature drops in winter have to be calculated, and the piping should be hot-insulated for freeze-proofing as necessary.
Piping, which is not always on stream, should be heat traced and hot insulated.
A circulation line should be provided at the terminal of each header so as not to stop flowing.
For pump coolers, water should also be circulated into spare stand-by pumps in order to minimize freezing trouble.
Winterization for Air and Nitrogen Piping
Special attention should be paid to the following.
Instrument air and nitrogen contain little moisture. Instrument air and nitrogen piping, therefore, are not required to be hot insulated; such piping should be constructed of materials for low-temperature services considering the lowest ambient temperature.
When plant air is dry, plant air piping may be bare. When it is not dry, it should be steam traced and insulated.
Winterization for Steam Piping
Attention should be paid, in particular, to the following items.
Steam traps should be installed in lines where condensate is likely to accumulate such as pockets or control valve bypass lines.
Even for the lines not frequently used, a steam trap should be installed at the inlet of each block valve to prevent freezing
Winterization for Steam Condensate Piping
1½” or smaller steam condensate piping should be heat traced and hot insulated.
2″ or larger steam condensate piping, which is always on-stream during plant operation, should be hot insulated.
2″ or larger steam condensate piping, which suffers from the intermittent flow of condensate accumulation for long periods of time, should be heat traced and hot insulated.
Winterization of Equipment
(1) Equipment requiring winterization:
(a) Equipment containing water and where water accumulates for a long period of time, such as separators, flash drums, and receiver boots, from which water has to be removed.
(b) Equipment containing fluids with a high pour point, high solidifying point, or high viscosity, will cause coagulation or hard-to-flow conditions.
(c) Equipment that is likely to have adverse effects on the entire unit, due to the partial condensation of hydrocarbons in gas, such as fuel gas drums.
(d) Equipment handling chemicals, such as caustic soda solution drums and inhibitor drums.
(2) Winterization of static equipment:
(a) Of towers, vessels, and heat exchangers, those handling fluids that may freeze should be provided with a drain valve at a position allowing the fluids to be drained completely during the suspension of plant operation.
(b) Parts of vessels (boots, etc.) that come into contact with water, nozzles, valves, and piping should be heat traced and hot insulated.
(c) No winterization is required for the equipment which can be heated by internal or external heating coils or similar facilities, even if the equipment contains liquid during plant shutdown.
(3) Winterization of air-cooled heat exchangers:
(a) Winterization of air-cooled heat exchangers should be subject to the requirements of API standard 632.
(b) Louvers should be installed to prevent excessive cooling when the inside tube skin temperature in winter decreases to lower than the freezing point or pour point of the fluid passing through the tube.
(c) For air-cooled heat exchangers handling heavy oils with a high pour point or viscosity, steam coils should be provided to prevent the plugging of tubes due to excessive cooling. The use of a hot-air circulation system may be considered necessary.
Data on the consumption of steam by air-cooled heat exchanger steam coils should be obtained from the manufacturer, together with the criteria for use.
Operation Mode Change
Winterization is studied per season, in view of energy saving, and is incorporated in piping design. Such cases are increasingly common.
(1) Winterization for water or moisture freezing prevention:
Heat tracing should not be done during seasons in which the lowest temperature is above 0°C.
Experience shows that when the temperature falls to about −5°C, water freezes, and bare piping, therefore, breaks at pockets.
(2) Winterization to maintain process fluid temperature higher than its pour point/solidifying point:
Heat tracing may be suspended per season according to the pour/solidifying points of the process fluid.
The heat tracing of the equipment and piping handling process fluids with 10°C or lower pour point may be suspended during seasons in which the lowest temperature exceeds 15°C. Seasons may be divided into two groups, for example, the summer season and the winter season, in view of the complexity of the operation.
Selection of Heat Tracing Method for Winterization
Heat tracing (Fig 2) for winterization should be steam tracing, as a rule. Electric tracing may be applied for the winterization of equipment and piping located away from the steam supply source or located in positions to which it is difficult to supply steam. Also, where the fluid is required to be maintained at 200°C or higher, electric tracing may be considered. Where steam cannot be used because of the properties of the internal fluids, hot water tracing may be applied.
Stress Analysis of HDPE, PE-RT, PP-H, PP-R, PVC-C, PVDF Piping
The main features of HDPE piping and other plastic piping related to steel piping are:
The allowable stress of plastic piping is dependent on service life and temperature. The equation is. The A, B, G, and J factors are stored in the Start-Prof material database
In some cases, swelling elongation due to a chemical reaction with the product should be considered. The swelling strain should be specified in the pipe properties
Linear expansion for plastic piping is much greater than for steel piping and caused by the Bourdon effect, thermal expansion, and swelling elongation
Pressure elongation of plastic piping is significant (Bourdon effect), and thermal expansion is also great.
Unlike steel piping, Young’s modulus (creep modulus) for plastic piping depends on service life. For higher service life – the lower creep modulus is used. The support loads, displacements, etc. are calculated at 100 minutes of creep modulus. The seismic analysis was performed using a 0.1-hour creep modulus.
In operating conditions, the average creep modulus is used (average between installation and operating temperature)
Allowable stress for plastic piping depends on the chemical resistance factor, laying condition factor, safety factor, and joint strength factor
The wall thickness check is performed only for straight pipes and not performed for fittings
Modeling of HDPE pipe in Start-Prof
To model HDPE piping or other plastic piping choose GOST 32388 code:
Choosing the Piping Code
Then create a pipe and choose the appropriate material from the database:
Selecting the Pipe Material
In an additional pipe, properties specify the chemical resistance factor (usually 1.0), Joint strength factor (0.4-1.0), and Laying conditions factor (0.8 for buried piping, 0.9 for underground piping in concrete channels, 1.0 for above-ground piping). The temperature range is multiplied by this factor. It considers the nonlinear distribution of temperature across the wall thickness. For plastic piping recommended value is 1.0 and for fiberglass piping 0.85 for fluid and 0.8 for gas if no other information is available.
The swelling strain is used for a chemical swelling elongation. It is the same as temperature elongation but caused by the chemical reaction between the pipe material and the product.
Allowable Stress Values
That’s all. All other job is the same as steel piping.
The Database contains all material properties. If there’s no material you need in the database, you can add its properties manually.
Adding the properties in Material Database
All load cases for analysis will be created automatically. After analysis, you get results according to the code.
Analysis Results
Videos for HDPE Piping Stress Analysis in START-PROF
Design Checking or checking of design is a process of validating a design and/or a design calculation to ensure that it is error-free and of good quality and is good for engineering and/or fabrication or whatever the end-use of it is.
Checking is also a process of value addition in terms of applying good engineering practices, aesthetics, reduction in cost and thereby providing better value to the client.
A design checklist is prepared for each important design process to aid in the design checking process.
Ensure a consistent design approach for similar pieces of equipment and/or unit area piping
Aesthetics
Responsibility Matrix for design check
Every individual is responsible and accountable for checking his deliverable to ensure quality and error-free design.
Every individual checks, signs, date, and then pass it on to the next individual.
Calculations/drawings received for checking by the next individual, without a sign and date, shall not be entertained/accepted!!!
Back-ups of holds and assumptions, if any, are maintained in an orderly manner before the issue
A signed and dated checklist, completely filled out is a must for any checked document as this is a quality record
The ultimate responsibility of quality and correctness lies with the lead as he is the one who enforces teams conformance to quality procedures
Checking is a collaborative effort. Every individual owns and is accountable for an error-free and quality product
Why Design Checking Adds Value
Owning responsibility and following good practices and procedures results in overall quality
The use of checklists ensures important points needing check are not missing out
Design reviews & inter-squad checks ensure interdisciplinary aspects are addressed in the design
Safety and constructability reviews ensure good overall layout, approach, constructability, maintenance, and operability
Incorporating fabrication/contractor-specific details and/or preferences into the design helps in easier and faster fabrication and lesser errors
Facilitates a once-through approach from start to finish thereby saving on time and schedule
Minimizes rework in design and at the field
Where do we stand today?
Ownership and accountability by individuals missing. “Next person will check”!!!
Do not prioritize tasks to ensure project schedules and goals are met
Work hard but do not “Work Smart”
Perform checking using either incomplete and/or superseded inputs
Do not capture design changes and revisions properly. Do not use revision notes.
Do not follow proper checking procedures, checklists, and colors from the initial stages. Keep this aside only for the final IFC check stage. Too late….!
Do not check important items/spelling. More focused on irrelevant aspects
Do not clarify checking procedures, standards, guidelines, checklists, etc. in the job notes upfront
Do not obtain early client approval on checking procedures and expectations
Do not have a checking and approval matrix for approval of various deliverables
Do not maintain discipline holds summary
Team and team leaders are often not aligned regarding the requirements/expectations of the project
Final number-crunching during the IFC issue period often affects productivity, and efficiency and lowers team morale
What Needs Improvement?
Follow a holistic approach toward checking
Approach and expectations shall be clarified upfront through job notes and induction sessions
Obtain client approvals and finalize checklists upfront
Pay attention to minor details. Spell check is also important
Work smart, prioritize, and be focused
Checklists and proper procedures shall be used religiously – this is mandatory
Always check against the latest documents to avoid rework.
Always start the final check process against a frozen and dated set of documents like P&IDs, LL, etc.
Lead to incorporate lessons learned in design into checklists as a process of procedural improvement
Lead to make expectations known to the team, fix individual responsibility and enforce accountability
Assign the right work to the right individual
The team is to be told that this is not an individual activity but a team effort. We sail or sink together!
Synopsis
Effective checking is integral to project success
Translates into quality, cost, and schedule advantage. Value+++
Checking is an innovative process, to find the best approach. One hat does not fit all!
We need to challenge a situation to come out as a winner. Think “out of the box”!
Piping Material Engineer: Roles, Responsibilities, and Activities
In the complex world of engineering and construction, the role of piping material engineers is often overlooked yet critically important. These professionals ensure that piping systems, which are fundamental to many industrial processes, function safely, efficiently, and economically.
You must be aware that there are three sub-disciplines inside the piping discipline, namely:
Piping Layout
Piping Stress
Piping Materials
Piping Materials Engineers are in the core group of the piping department. Broadly, the piping material engineer is responsible for the quality of material, creating a project pipe class, and various piping specifications required in a project to fabricate and test the piping system. Piping Materials Engineers are also sometimes called Piping Specification Engineers.
Who are Piping Materials Engineers
By Definition Piping Materials Engineers are piping engineering individuals who are responsible for creating the project piping classes and the numerous piping specifications necessary to fabricate, test, insulate, and paint the piping systems.
Whatever the title, the piping material engineer (PME) is a very important person within the Piping Design Group and should be dedicated to a project from the bid stage until the design phase has been completed. He or she should also be available during construction and through to mechanical completion.
Normally, the lead piping material engineer, the individual responsible for all piping engineering functions, usually reports directly to the project lead piping engineer. Depending on the size of the project, the lead piping material engineer may be assisted by a number of suitably qualified piping material engineers, especially during the peak period of the project. This peak period is early in the job, while the piping classes are being developed and the first bulk inquiry requisitions are sent out to vendors.
Roles and Responsibilities of Piping Material Engineers
Layout and Stress Engineer’s activities are quite evident to most people in the industry, however, the activity performed by a Piping Material Engineer is always less known and underrated. Many of us think that the piping material engineer performs only MTO (material takeoff). However, a Piping Material Engineer performs a lot of activities in a project, and his role is very important in a project.
Piping Material Engineer’s activities include but are not limited to the following:
Make sure that everyone in the piping group is aware of the materials of construction that can be used for piping systems.
To Liaise with the following departments: Piping Design and Stress, Process, Instrumentation, Vessels, Mechanical, Structural, Procurement, and Material Control.
To Maintain project technical files and update Company standards
To Perform the inter-disciplines checking for the part of documents in accordance with the scope of the piping material section.
So to summarize a Piping Material Engineer must be a Good Communicator, must have experience in Piping Design and Piping Material Properties, must be aware of corrosion characteristics of Piping Materials, must be aware of welding Processes necessary for the fabrication of piping systems, and must have a basic understanding of all other disciplines which have an interface with piping. Finally, He must be aware of economics which includes the material selection to reduce costly high-pressure and alloy piping runs and reduce the use of odd, high-cost fittings.
Activities of a Piping Material Engineer
Here are the main activities of a piping material engineer, presented in the order they typically occur as a project moves from initial planning to detailed design.
1. Development of Project Piping Classes
In process plants, there are two main types of piping systems: process piping and utility piping.
Process Piping: This is the main pathway for materials in a plant. It carries feedstock, transports products through various equipment, and delivers the finished product for further processing. Process piping can be split into:
Primary Process: The main flow of materials.
Secondary Process: Systems for recycling materials.
Utility Piping: This supports the primary process and is divided into three groups:
Support: Includes instrument air, cooling water, and steam.
Maintenance: Covers plant air and nitrogen.
Protection: Comprises foam and firewater. Other utility services include drinking water.
Piping Classes
Each piping system is assigned a piping class that outlines all necessary components for construction. A piping class includes:
Design conditions (temperature and pressure)
Corrosion protection
List of components
Branch tables
Special assemblies
Support notes
Both process and utility piping systems operate under various temperatures and pressures. Important factors to analyze include:
After examining these factors, piping systems can be grouped into classes that share similar characteristics, such as size, pressure, temperature, and joining methods. This standardization simplifies procurement, inspection, and construction.
However, there’s a balance to strike. Having too many classes can complicate paperwork and lead to errors, while too few classes may require using expensive materials for less critical services, which is known as being “overspecified.” It’s the job of the piping material engineer to optimize this classification for the project’s benefit.
For example, a typical oil and gas separation plant might have around 10 process piping classes and a similar number for utility piping. More complex petrochemical facilities may need over 50 classes to accommodate various processes and their specific temperature and pressure requirements.
2. Writing Specifications for Fabrication, Testing, Insulation, and Painting
Specifying the right materials for pipes is useless if they are built and installed by unqualified workers using poor methods, and if testing, insulation, and painting are not done properly.
The piping material engineer is tasked with creating detailed specifications for these activities to ensure they meet industry standards and the client’s needs. While each project is unique, many share similarities, and most Engineering, Procurement, and Construction (EPC) companies have general specifications that address these areas.
3. Creating Data Sheets for Process and Utility Valves
Every valve used in a process plant must have a dedicated valve data sheet (VDS). This document acts like a passport for the valve, detailing its size range, pressure rating, design temperature, materials, testing and inspection procedures, and all relevant design codes. The VDS is crucial for efficient procurement and future maintenance of the valve.
4. Creating a List of Piping Specials and Data Sheets
A piping system mainly consists of common components like pipes, fittings, and valves. However, there are also less common items, known as piping specials, such as strainers, hoses, steam traps, and interlocks. Each special item must have a unique SP number for identification.
The piping material engineer is responsible for creating and maintaining a list of SP numbers, ensuring that each special item is clearly identified by its type, material, size, and rating. Each piping special also requires its own data sheet for efficient procurement and maintenance.
5. Assembling Piping Material Requisitions with Supporting Documents
Once the piping specifications are finalized and initial quantities are determined by the Material Take-off Group, the piping material engineer assembles the requisition packages. The Procurement Department then divides the piping requirements into several requisitions, which will be sent to manufacturers that specialize in specific piping components, including:
Pipe: Seamless and welded (carbon and stainless steel), exotic materials (Inconel, Monel, titanium)
Pipe fittings: Seamless and welded (carbon and stainless steel)
Valves: Gate, globe, and check (small bore, 1.5 inches and below; 2 inches and above)
Ball valves: All sizes (carbon and stainless steel)
Special valves: Non-slam check valves, butterfly valves
Stud bolting: All materials
Gaskets: Flat, spiral wound, ring type
Special piping items (SPs): Strainers, hoses, hose couplings, sight glasses, interlocks, etc.
To obtain competitive bids, inquiries are sent to multiple manufacturers for each group of components, inviting them to provide their best prices. This includes not only supplying the items but also testing, certification, marking, packing, and shipping to the site if needed.
6. Reviewing Vendor Offers and Creating a Technical Bid Evaluation
Many clients maintain an “approved bidders list,” which includes vendors deemed suitable to supply materials based on their past performance and reliable recommendations. Prospective vendors are given a deadline to submit their bids, which must cover the specified requirements.
To foster competition, it’s best to shortlist three to six qualified vendors, ensuring they all feel they are competing with others. Even if some vendors drop out, all should believe they are in a competitive environment.
The piping material engineer evaluates all feasible bids, ensuring each vendor meets the technical specifications and is deemed “fit for purpose.” If a vendor cannot meet the requisition requirements, they are marked as technically unacceptable and excluded from further consideration.
During this evaluation, the piping material engineer creates a bid tabulation spreadsheet that lists the technical requirements for each item and assesses each vendor’s compliance. This includes evaluating materials, design codes, testing, certification, painting, as well as non-technical areas like marking and packing. The required delivery date is provided by the Material Control Group to assist in final negotiations.
The Procurement Department handles all commercial aspects, while the Project Services Group determines the delivery schedule. It’s crucial to choose a vendor who is technically acceptable and offers the best overall value, rather than just the lowest price, as the cheapest option might end up being more costly in the long run.
7. Reviewing and Approving Vendor Documentation After Purchase Order Placement
After placing an order, it’s vital to review the vendor’s documentation. Vendors must provide support documents such as inspection and testing plans, general arrangement drawings, material certifications, test certificates, and production schedules.
The piping material engineer must review and approve this documentation before the final payment can be made to the vendor.
8. Vendor Visits
The piping material engineer may need to visit the vendor’s facility to observe testing or attend clarification meetings. Some piping items are more complex due to their materials, design, or pressure ratings, requiring closer attention to ensure that the correct materials are supplied without causing production delays.
To facilitate this, the following activities should be considered:
Bid clarification meeting: Ensures the vendor fully understands the requisition.
Pre-inspection meeting: Discusses production, inspection, and quality control after the order is placed.
On-site supervision: Involves having the requisition engineer at the vendor’s facility during critical manufacturing phases.
Dedicated inspector: Places an inspector at the vendor’s site to oversee inspection and testing, ensuring specifications are followed.
The first two activities are low-cost and generally standard, while the last two may be more expensive and should be evaluated based on the complexity of the order and lead times.
Each requisition is unique; simple orders with new vendors might need more oversight than complex ones with established vendors. The decision to conduct vendor visits should also consider the inspection budget, as inadequate funding could limit on-site supervision.
Remember, receiving incorrect materials can result in high replacement costs and project delays, making it essential to ensure proper oversight, especially for custom items or those with long lead times (three months or more).
9. Bids for New Projects
In addition to project-related activities, the piping material engineer may also participate in bids for new projects invited by clients. This stage involves preliminary engineering, where accuracy is crucial, based on the client’s brief. Typical tasks include developing preliminary piping classes, basic valve data sheets, and specifications for construction, inspection, and painting.
A piping material engineer may work as part of a dedicated project task force or within a corporate group managing multiple projects at different stages. The former is often preferred, as it allows for a deeper familiarity with the evolving project.
The role of a piping material engineer is both diverse and rewarding, offering continuous learning opportunities. Even if a project has the same client, process, and geographical location, variations in personnel, budgets, and market conditions lead to unique challenges. Each project brings its own set of intricacies.
It’s essential to document and maintain your knowledge—both technical and logistical—through organized files, whether digital or in hard copy.
Regardless of whether you stay with one company for 30 years or work for multiple companies for shorter stints, the role of a piping material engineer is highly respected within the field and across projects. While it is on par with piping layout or stress engineering, its significance should not be underestimated. Proper material selection is critical; if the wrong materials are used, no matter how well the pipe is laid out, all routing efforts become irrelevant.
Piping Materials Engineer Jobs
Piping Materials Engineers are highly sought-after professionals in various industries where the design, construction, and maintenance of piping systems are critical. These engineers play a vital role in ensuring the integrity, safety, and reliability of piping networks. Here are some of the key industries where Piping Materials Engineers are recruited:
Oil and Gas Industry: Piping Materials Engineers are in high demand in the oil and gas sector. They work on projects involving pipelines, refineries, offshore platforms, and petrochemical plants.
Chemical and Petrochemical Industry: Piping Materials Engineers play a critical role in selecting materials that can withstand the corrosive and hazardous chemicals used in chemical processing plants and petrochemical facilities. They ensure compliance with industry standards to maintain safety and productivity.
Power Generation: Power plants, whether nuclear, fossil fuel-based, or renewable energy facilities, require extensive piping systems for the transport of steam, water, and other fluids. Piping Materials Engineers are responsible for selecting materials that can handle high temperatures and pressures.
Pharmaceutical and Biotechnology: Industries like pharmaceuticals and biotechnology rely on sanitary and high-purity piping systems for the production of drugs and biologics. Piping Materials Engineers work to maintain product integrity and regulatory compliance.
Mining and Minerals Processing: The mining industry utilizes extensive piping networks for transporting ores, slurries, and chemicals. Piping Materials Engineers select materials that can withstand abrasive environments and prevent corrosion.
Water and Wastewater Treatment: In municipal and industrial water treatment plants, Piping Materials Engineers are responsible for designing corrosion-resistant and durable piping systems to handle water purification, distribution, and sewage treatment.
Food and Beverage Industry: Food processing and beverage production facilities require sanitary and hygienic piping systems. Piping Materials Engineers ensure that materials meet FDA (Food and Drug Administration) and other regulatory requirements.
Nuclear Industry: Piping Materials Engineers in the nuclear industry focus on materials that can withstand radiation and extreme conditions. They play a crucial role in the safe operation of nuclear power plants.
Maritime and Shipbuilding: In shipbuilding and maritime industries, Piping Materials Engineers are involved in the design and maintenance of complex piping systems for ships, offshore platforms, and maritime infrastructure.
Building and Construction: Piping Materials Engineers also find opportunities in the building and construction sector, where they work on plumbing systems, heating, ventilation, air conditioning (HVAC) systems, and other building infrastructure projects.
Renewable Energy: With the growing focus on renewable energy sources like solar and geothermal, Piping Materials Engineers are involved in designing and maintaining piping systems for these technologies.
Automotive Industry: In automotive manufacturing, Piping Materials Engineers work on the design of fluid-carrying systems, such as fuel lines, brake lines, and cooling systems.
Research and Development: Some Piping Materials Engineers are employed in research and development roles in materials science, working on innovations in materials for various industries.
Salary of a Piping Materials Engineer
The salary of a Piping Materials Engineer can vary significantly depending on several factors, including experience, location, industry, education, and the specific employer. In India, the salaries are at the lower end whereas in the USA and Europe, the salaries are higher.
Below, I’ll provide a general salary range for Piping Materials Engineers in the USA:
Entry-Level: Piping Materials Engineers who are just starting their careers can typically expect a salary in the range of $48,000 to $80,000 per year. This can vary based on location and industry demand.
Mid-Career: With several years of experience, Piping Materials Engineers can earn salaries ranging from $80,000 to $120,000 per year.
Experienced/Senior: Those with extensive experience and expertise in Piping Materials Engineering can earn salaries exceeding $120,000, often reaching $150,000 or more per year.
Stress analysis is a complex task and in any process unit, there are a huge number of lines exist which run from one location to another. Analyzing all lines will take a lot of time which in turn will increase the engineering time and corresponding cost. So every engineering organization in this field has set up some guidelines for deciding which lines are to be stress analyzed using pipe stress analysis software (Caesar II, Autopipe, Caepipe, START-PROF, or Rohr II).
What is a Critical Line List or Stress Critical Line List?
A Stress Critical Line List or SCLL is a listing of all critical lines requiring attention from a piping stress engineer during the piping design phase. It is the piping stress engineer’s responsibility to prepare one Critical Line List (CLL) by isolating the non-stress critical lines from the stress critical line based on the criteria provided in the stress analysis specification. Piping Critical Line List is also known as Flexibility Log in some EPC organizations or design consultancies.
All those critical lines are then categorized into some number of stress systems so that the stress system numbers can be easily found from the generated critical line list. The number of stress critical lines in each stress system is decided based on the engineering judgment of the stress engineer. The stress Critical Line List is an important deliverable from the piping stress team. The main inputs required from the stress critical line list preparation are:
Ideally, the critical line list should be updated as and when the process line list is updated. But to reduce frequent changes many organization prepares only three revisions of the stress critical line list. Those:
Preliminary Stress Critical Line List during the start of the project upon receipt of the first set of line lists and P&ID
Advanced Critical Line List just before 60% model review and
Final Stress Critical Line List after 90% model review.
Types of Stress Critical Lines
Stress Critical Lines are normally divided into a few groups for deciding critical lines. Those are:
Equipment Critical Lines: Lines connected to Rotary Equipment and Critical Static equipment fall in this category. For example, lines connected to pumps, compressors, and turbines are by default stress critical and require analysis using the software.
Support Critical Lines: Lines for which engineered supports are required fall in this category. Example: Supports requiring spring hangers, Pipes with SS or SDSS material where normal CS supports can not be used, etc.
Relief Critical Lines: Pipes experiencing relief loads come into this category. For example, the line connected to pressure safety valves, rupture disk, etc.
Material Critical Lines: Pipes made from SDSS and non-metals like GRE, FRP, Aluminum alloy, etc. fall in this category.
Service Critical Lines: Piping systems carrying category M fluid service, hazardous fluid service, severe cyclic condition, etc. fall into this category.
Temperature Critical Lines: Lines carrying fluids having high temperature comes into this group.
The basis for deciding Stress critical lines
The main factors which decide stress critical lines for preparing a critical line list are as follows:
Every organization has its own guidelines and the guidelines vary from project to project. The following write-up will provide a few criteria for deciding stress critical lines. This is only an idea of how differentiation occurs. The user is requested to check project-specific documents for use in any project. Mostly the critical lines for which stress analysis is to be performed by formal computer analysis consist of the following lines:
All Pump (Centrifugal-API/ANSI, gear pump, Screw pump) suction and discharge piping (4 inches and larger).
Centrifugal Compressor inlet and outlet piping.
Lines to and from steam generators.
Reciprocating pump and compressor suction and discharge piping.
Piping requiring expansion joints or other proprietary expansion devices.
All Fiberglass, aluminum alloy, refractory, or elastomer-lined piping.
All piping systems connected to FRP, plastic, glass-lined steel, or brittle equipment
Lines subjected to non-thermal movements (Expected differential settlement between structures, structure-equipment, etc., process equipment growth, header growth, tower growth, or other significant displacements, etc.)
All lines 8” and larger operating above 150 deg. C (300 deg. F) and greater.
All lines 20” and larger operating above 80 deg. C (200 deg. F) and greater.
All lines 36” and larger.
All lines operating below -45 deg. C (-50 deg. F) which requires special “cold” supports.
All plastic-lined piping systems. Special attention shall be given to adding enough additional supports to limit the external forces and moments in the flange connections to avoid an extra risk of flange leaks.
Lines with special design requirements
All Safety pressure-relieving systems 4 inches and larger (not including thermal reliefs)
In addition, the piping effects of other conditions such as temperature gradients that could cause thermal bowing or where piping is connected to equipment with significant thermal growth may warrant detailed computer analysis.
For thin wall piping, if the D/T ratio exceeds 100, the following requirements are applicable:
The design and support of piping systems using this specification should be reviewed by a stress engineer. Support and spans of thin wall piping systems are not covered by current Project practices and therefore must be designed for each application.
Stub-in connections per 304.3.2 thru 304.3.4 of ASME B31.3, are not allowed for run pipe with D/T greater than or equal to 100 and the branch diameter is greater than one-half of the header diameter.
Lines connected to non-ferrous equipment.
Underground process lines with more than a 30-degree difference between design and ambient temperature.
All vertical lines, connected to vertical vessels that require pipe supports or guides from that vessel.
All lines, 4 inches and larger subject to external pressure or vacuum conditions.
All lines, subject to vibration, as specified by Process, due to high-velocity flow, high-pressure drop, water hammer, or mixed phase flow.
All lines that are connected to equipment constructed of thermoset or thermoplastic materials or that are glass, refractory, or elastomer lined.
