Plant Design and Installation

4

Learning Outcome

When you complete this learning material, you will be able to:

Explain the codes and procedures involved in the design and construction of a new plant.

Learning Objectives

You will specifically be able to complete the following tasks:

  1. 1. State the codes and standards, which must be followed when designing and building a new plant.
  2. 2. Describe the steps involved in developing specifications and contracts for new installations and modifications.
  3. 3. Explain the major steps involved in the design and construction of a new plant.
  4. 4. Explain the roles and responsibilities in the design and construction of a new plant.
  5. 5. Explain how the design and construction of a new plant are administered and controlled.

Objective 1

State the codes and standards that must be followed when designing and building a new plant.

When a new plant is designed and built, the codes and standards for the location of the new plant must be followed. A plant installed in Canada must be built to standards and codes used by the province. For example, an oil sands plant installed in Alberta must meet all of the standards and codes adopted in Alberta.

Because the codes are updated regularly, the newest version of the codes must be used. Each engineering discipline has codes and standards that must be followed. Engineering disciplines include: environmental (includes water and air), civil, chemical, mechanical, and electrical.

Provincial jurisdictions also require companies to obtain work permits before work on buildings or facilities commence. These permits fall under the following areas: electrical codes, plumbing codes, building codes, fire codes, and gas codes. Other standards that must be adhered to are environmental, air, water and wastewater, and transportation.

Local standards involve such items as traffic, noise, odour, and appearance.

Benefits of obtaining a permit are that: the installation conforms to construction and safety standards accepted under the Safety Codes Act, and certified codes officers do inspections.

The following codes and standards are declared in force with respect to pressure equipment:

American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code - 2001; The ASME Codes are extensively used by power engineers, because they apply to power boilers, pressure vessels, and pressure piping.

The standards developed by the various organizations become a base for the codes in order to determine the quality of the material and the workmanship.

Research and Testing Organizations

Professional Associations

Trade Associations

Objective 2

Describe the steps involved in developing specifications and contracts for new installations and modifications.

Feasibility Studies

Before an industrial plant can be constructed, an engineering or feasibility study must be completed to evaluate the feasibility of the plant. The study is used to determine the plant size and to estimate costs. The company building the plant may have a large enough engineering staff to complete the study itself, or it may be contracted to an engineering company. A separate engineering company does the detailed engineering. Detailed engineering has the information and specifications required to construct the plant.

The primary emphasis of the engineering feasibility study is economics. The study is used to determine the cost of the new plant and to ascertain its economic viability – whether the plant can make a profit. If the plant design appears profitable, the study is used to obtain capital funds to build the plant. The study includes the cost of building the plant as well as other related costs such as: operation of the plant, maintenance, depreciation, insurance, interest, and taxes. With this information, an operating and maintenance budget for the proposed plant is developed.

The feasibility study must also address other issues that will affect the viability of building and operating a new plant, and which also impact the cost of construction and operation. These include the following:

Detailed Design and Specifications

After a new plant site is selected and the various government approvals are obtained, the design of the plant is finalized. Usually, the general plant design and physical size are required to get the approvals.

Detailed design follows the acceptance of the feasibility study, funding, and procurement of permits. There are different priorities at each plant, but some of the basic

choices that have to be made are: type of fuel used, the production process used, amount of auxiliary equipment, the types of instrumentation and control, and power supply.

The engineering company contracted to design the plant finalizes the design of the plant. Plot plans for the plant site, including roads, buildings, process units, and offsite facilities are produced. The engineering company completes the design drawings that tie the process units together. The engineering company produces drawings and specifications, with the amount of detail required for construction companies to create competitive bids.

The larger process areas of the plant are often purchased as standard or proven designs. For example, a new power plant may have a steam generator supplied by Babcock and Wilcox and a turbine supplied by Hitachi. These are proven designs that have been used in other plants. Babcock and Wilcox supplies the detailed drawings and specification sheets for the steam generator and its associated equipment. Hitachi supplies the drawings and specifications for the turbine and electric generator and associated equipment. The engineering company completes the engineering required to attach the equipment supplied by the main vendors. This engineering includes such things as interconnecting piping, electrical systems and instrumentation.

The plant owner stays involved during the design process. Any additions or options the owner specifies are incorporated into the design. It is cost effective to incorporate changes to the design at the design stage, rather than after construction has commenced.

Drawings and Specifications

Drawings and specifications are necessary to obtain bids for construction, to supervise the purchasing, and for construction of the plant. The drawings are a graphic representation of the plant, while the specification sheets provide details of the components of the plant. The drawings include the location of the equipment including interconnecting piping and wiring. Between the two, the work to be done is clearly defined. The specifications should include the details of each item shown on the drawings. Specifications are intended to be very detailed although they also include some general stipulations and conditions relating to the work as a whole.

For example, in a piping system for an industrial plant, the drawings show the piping layout including detailed dimensions. The piping drawings also refer to the piping specifications. This is done with a piping specification number. The Process and Instrumentation Drawing (P & ID) in Fig. 1 contains piping line numbers. Refer to the specification number to obtain details for the piping. The specifications for the piping lists all of the design requirements including:

Developing Drawings and Specifications

The engineering company produces preliminary drawings that contain enough detail to do the feasibility study of the plant but not enough detail to construct the facility. Drawings included in the feasibility study are Process Flow Diagrams (PFDs) of the overall plant process streams. There are also plot plans showing all roads, buildings, offsite facilities, and storage facilities. At this stage a preliminary set of Process Flow Diagrams has been created.

The design specifications and the isometric or Computer Assisted Drafting (CAD) drawings are done after the feasibility study has been completed. This is the detailed design stage. At this stage, the drawings and plot plans have complete details and refer to the design specifications. The specifications must also contain all the details needed for purchasing materials and for plant construction.

Plant Modifications

When a plant adds new equipment, the existing specifications are used if possible. For example, if a new feedwater pump is added to an existing system, the P&ID drawings are modified to include the additional piping. The piping specifications listed on the P&ID refer to the existing specifications. When new piping is added with different specifications from the existing piping, the specifications sheets have to be updated. This happens if the new system uses different material, is a different size, or has different pressure or temperature ratings.

If a new unit (boiler or process train) is added to an existing plant, it will have its own set of drawings and specifications. Existing specifications can only be used when the new unit is similar to existing units.

Process and Instrument Diagram (P&ID) of a Fractionation System

The diagram illustrates a fractionation process. On the left, the Fractionator (V-401, 48" OD x 52'-0" T/T) is the central vessel. It is connected to a Fractionator Reboiler (E-401) at the bottom. Steam (LPS) enters the reboiler through a control valve regulated by a temperature controller (TIC) on the column. The bottom product is pumped out by pumps P-401A/B to storage. The overhead vapor from V-401 goes to the Overhead Condenser (E-402), which uses cooling water. The condensed liquid flows into the Reflux Accumulator (V-402, 48" OD x 15'-0" T/T). From V-402, liquid is pumped back to the top of the column as reflux or sent to storage as product, controlled by a level controller (LIC) on the accumulator. Non-condensables from the accumulator are vented to the flare or fuel gas system. Instrumentation includes pressure indicators (PI), temperature indicators (TI), flow indicator controllers (FIC), and level indicator controllers (LIC) throughout the system.

E-401
Fractionator
Reboiler
V-401
Fractionator
48" OD x 52'-0" T/T
P-401A/B
Product & Reflux
Pumps
E-402
Overhead
Condenser
V-402
Reflux
Accumulator
48" OD x 15'-0" T/T
Process and Instrument Diagram (P&ID) of a Fractionation System

Figure 1
Process and Instrument Diagram

Objective 3

Explain the major steps involved in the design and construction of a new plant.

PLANT DESIGN

The design of a new plant goes through several phases, even before the detailed engineering begins. The first step is the feasibility study used to decide whether the plant is economically feasible. Once through the feasibility phase, the engineering proceeds to the detailed design which produces the drawings and specifications needed to purchase materials for construction.

Engineering Study

This phase is also called a feasibility study. In its basic form, it is used to determine whether the plant should be constructed and if the plant makes economic sense for the corporate or government owner. The study can be carried out by the purchasing company's engineering staff or by a contracted engineering company. Some of the things decided in the study are:

The engineering study includes a report used to obtain capital funds for plant construction. It includes outlays for such items as operations, maintenance, depreciation,

insurance, interest, taxes, and a budget. It includes recommendations for such items as:

The engineering study often includes economic alternatives. Such alternatives could include different plant locations, various plant output sizes, or use of different fuels.

Detailed Design

The detailed design process follows the engineering study and the decision to proceed. The detailed design builds upon the work accomplished in the engineering study but contains much more detail. Items included in the detailed design include:

Drawings and Specifications

As the engineering continues, all of the information is summarized in drawings and specifications. The design drawings may be paper-based, or computer-based on CAD programs, or a combination of the two. The design may also include the construction of a scale model of the plant equipment. The model is useful to determine placement of equipment, location of pipe on pipe racks and to train plant personnel. Any interference with beams or ladders can be easily detected. Three-dimensional (3-D) computer images of the equipment are generated. This eliminates the need for an actual scale model. The detailed design drawings and specifications include all details needed to construct the plant. Details included are:

Performance Specifications

Performance specifications are used for specifying outputs of pumps, fans, turbines, motors, and electric generators. For example, the desired output of a pump is given to a pump manufacturer. The manufacturer or vendor then supplies a pump capable of meeting the output at the design conditions. Because manufacturers have specialized experience they choose the model best suited for the application. Pump performance is checked during the performance run of the plant.

PLANT CONSTRUCTION

The plant construction also goes through several phases. A construction company or primary or general contractor must be selected. Once selected the primary contractor oversees the construction of the plant. Once the plant is constructed, the equipment is started up (or commissioned).

Bidding or Negotiation Phase

The bidding phase follows the detailed design phase. Companies with the expertise to construct the plant are located. A short list of the most suitable companies is compiled. This list may be one to six companies, and a copy of the plant design is given to each one. Each company supplies a bid based upon the plant design. The bid documents detail the timeline, forms of payment, and all other required details. After the bids are received, a bid review process analyses the competing bids. From this analysis the winning bid is selected. It is usually the bid with the lowest cost. In some cases, the lowest cost bid includes some other consideration or requirement which is not acceptable, in which case another bid may be accepted instead.

Construction Phase

After a successful bid is accepted for the construction of the plant, work at the site can commence. During the construction phase, the engineering staff changes its focus to contract administration and quality assurance. Contract administration includes resolving any design changes. These may be a result of omissions from, or factors that do not comply with, the original design, or from changes requested by the plant owners. Change orders add to the cost of the project, as the changes must be re-engineered and changes made to the drawings and specifications. Smaller field changes require little or no engineering changes.

The construction takes place with many trades working on the project simultaneously. The basic order of the work is listed below.

Pre-commissioning

Pre-commissioning begins once the piping is complete. It includes steps that have to be completed before the commissioning or startup of the plant can begin. Activities included in the pre-commissioning schedule include:

After the pre-commissioning steps are complete, the plant startup can begin.

Commissioning

Commissioning is the term used to describe the process startup of a new plant. The commissioning is done in systems, starting with the plant offsites and utilities and working through the process, until the final product is produced. It is critical to go slowly, following the manufacturers recommendations. Limits on temperatures and pressures must be closely adhered to. The steps differ for different types of plants. A sample order of systems startup is listed below.

Objective 4

Explain the roles and responsibilities in the design and construction of a new plant.

Owner

There are many different stakeholders in the design and construction of a new plant. They have different or related responsibilities during the phase design and construction phase.

The Corporation that is paying for and will own and operate the new plant is called the owner. The owner is involved with the work before the detailed design engineering starts, including:

Staffing the new facility is also the responsibility of the owner. The new plant requires operations personnel, maintenance people, and all types of support staff such as laboratory technicians, human resources, and safety personnel.

Training the new staff is also the responsibility of the plant owner. Often the new staff comes from existing facilities with the same owners, but staff are also hired from outside the company. All staff must become familiar with the new facility and management system.

The owner and the engineers employed by the owner must be involved in all stages of the design and construction of the new plant. The owner's engineering department is heavily involved in the conceptual and engineering feasibility studies for the new plant. Most of the detailed engineering is contracted to the design engineering company. The design engineering company may or may not be the same company that is doing the construction of the plant.

Designers

The detailed engineering or design engineering is usually contracted to an engineering company with experience designing the type of plant under construction. The design engineers are responsible for the following tasks:

General Construction Contractor

The general construction contractor has the overall responsibility for building the plant. The general contractor does varying percentages of the work and subcontracts out other sections of the work. The general contractor handles the following types of jobs:

Subcontractors

The general contractor hires subcontractors to do specialized work. The subcontractor can do this work more economically than the general contractor. The types of jobs often contracted out are:

Construction of large portions of a plant, such as the steam generator for a coal fired power plant, can also be contracted out.

Quality Control (QC)

Various QC personnel handle the quality control during the construction of a new plant. Basic QC, such as x-raying of piping and steelwork, is usually conducted by subcontractors under the control of the general contractor. The general contractor can also conduct all of the pressure testing of the piping to check that the plant has been constructed according to the design drawings.

The engineering company's QC people or the owner may also be involved. There are specialized inspection tasks they are suited to such as:

Operations Staff

The main task for operations people is to learn as much as possible about the new plant before they start it up. They need to know the processes in detail. The plant designers may put on training courses to explain the operation of all processes and the functions of the main control loops. Some of the duties of operations people during the construction phase of the project include:

During the plant start or commissioning, the operators take control of the plant systems and start up the plant. All equipment must be watched very closely during this phase. Often extra operators are used during startup, for training and to help with the commissioning of new equipment.

Maintenance

The plant maintenance staff must also learn as much as possible about the new plant and its equipment. Some of the duties of the maintenance staff include:

Objective 5

Explain how the design and construction of a new plant are administered and controlled.

ORGANIZATION OF THE PROJECT

The company building the plant must decide how much work on the project its own employees can do in-house. It then decides how and with what firms to contract the remaining work.

Each project is organized according to the scale of the plant and the requirements of the owner. Although no projects are organized exactly the same way, there are a number of general options. Combinations of each type can be tailored to meet a particular project's requirements.

Fig. 2 illustrates the number of workers on a power plant construction site. The job must be well planned and coordinated so the workers complete their jobs by the startup date. A chart such as Fig. 2 will enable the planners to predict how many workers are required in each trade at any given time, so that the required staffing levels for each week can be planned for and organized in advance.

Figure 2: Workers on a Construction Site. A line graph showing Manpower (Y-axis, 0 to 700) versus Time (X-axis, 1 to 4). The graph shows the total manpower and the contribution of various trades over time. The total manpower peaks at 700 around time 2.5. The trades shown are Civil, Pipe Fitters, Electricians, Non-Manual, Others, and Subcontracts. Key events marked are 'FIRST CONCRETE' at time 1 and 'FUEL LOAD' at time 4. The 'Commercial Operation' phase begins after time 4.

The graph illustrates the distribution of manpower across different trades over a four-month period. The Y-axis represents Manpower (0 to 700) and the X-axis represents Time (1 to 4). The total manpower curve peaks at 700 around time 2.5. The individual trade curves are as follows:

Trade Peak Manpower Approximate Time of Peak
CIVIL 180 2.5
PIPE FITTERS 150 2.8
ELECTRICIANS 100 3.0
NON-MANUAL 97 2.2
OTHERS 80 1.5
SUBCONTRACTS 90 3.5

Key events marked on the graph:

Figure 2: Workers on a Construction Site. A line graph showing Manpower (Y-axis, 0 to 700) versus Time (X-axis, 1 to 4). The graph shows the total manpower and the contribution of various trades over time. The total manpower peaks at 700 around time 2.5. The trades shown are Civil, Pipe Fitters, Electricians, Non-Manual, Others, and Subcontracts. Key events marked are 'FIRST CONCRETE' at time 1 and 'FUEL LOAD' at time 4. The 'Commercial Operation' phase begins after time 4.

Figure 2
Workers on a Construction Site

Design – Bid – Build

In this arrangement the owner gets a scope definition with basic engineering partly complete. An engineering company completes the detailed engineering. When working drawings and designs are completed, bids are sent out for the construction of the plant. Construction is contracted out to a general contractor. The plant scope is not finalized until late in the project. The cost of the project cannot be finalized until all changes in scope have been completed. Different approaches used for design and construction, which are detailed in the following sections, include Reimbursable Engineering Procurement, Design – Build, and Lump Sum Engineering Procurement.

Reimbursable Engineering Procurement Construction (EPC)

Procurement is the purchasing phase of the project. In the Reimbursable EPC arrangement, with the basic engineering about 10% complete, an engineering company is selected to do the detailed design, procurement, and construction. The engineering company is paid the actual cost plus a fee for each project phase. The total cost of the project is not known until all phases of the project are complete.

Design – Build

With the basic design engineering about 20% complete, the owner selects a company to complete the detailed design, order the equipment, and construct the plant. The entire project is done based on a final, lump sum payment. Risk for the owner is reduced, as the price for the entire project is fixed up front. The final payment is often made after the performance run of the plant has been completed. This type of arrangement combines the roles of the designer and the general contractor.

Lump Sum EPC

When the basic engineering is about 20% or more complete, the owner selects a company to do the design engineering. The scope has to be well defined upfront, so the companies bidding on the work can accurately estimate the costs of each phase. With the design engineering complete each phase is put out for bids on a lump sum basis. A contractor is selected for each phase of the project.

Construction Field Administration

When the general contractor has obtained a contract by any of the methods described a plan for scheduling and completing the construction is developed. Extensive planning and scheduling is required for a large engineering project. There must also be a method of monitoring the construction progress against the construction schedule. Fig. 3 shows a typical organizational chart for a construction project. This chart is for staff at the construction site. The top level of structure shows the owner, or company, that is building and will own the new facility. The resident manager is the plant manager. The headquarters engineering site support is the engineering company's head office staff that will support the local engineering office.

The next level of diagram breaks out the larger groups at the site into engineering, construction staff, and services or office functions. The construction group contains all the construction related staff, from supervision to safety personnel.

The services area contains groups such as purchasing, accounting, and document control.

For the project to be completed in a timely and cost effective manner, all personnel must function well and communicate effectively with each other and with all groups.

Organizational chart for a Power Plant construction field organization. The hierarchy starts with Quality Control, Resident Management, and Owner at the top. Resident Management oversees Engineering, Construction Inspection, Construction, and Services. Engineering includes Office and Field Engineering leading to Contract Administration. Construction includes Rig Operator, Material Control, Labor Relations Coordinator, and Safety Officer, leading to Area Supervisor and Typical Areas (Construction Supervisor, Field Engineering, Planner, Safety Officer). Services include Office Management (Purchasing, Field Accounting, Typical Areas: Admin Tech, Clerical Staff, Nurse, Logistics Officer) and Cost & Schedule Control (Material Control). 
graph TD
    QC[Quality Control] --- RM[Resident Management]
    O[Owner] --- RM
    RM --- E[Engineering]
    RM --- CI[Construction Inspection]
    RM --- C[Construction]
    RM --- S[Services]
    E --- OE[Office Engineering]
    E --- FE1[Field Engineering]
    OE --- CA[Contract Administration]
    FE1 --- CA
    C --- CS[Construction Supervisor]
    CS --- RO[Rig Operator]
    CS --- MC1[Material Control]
    CS --- LRC[Labor Relations Coordinator]
    CS --- SO1[Safety Officer]
    RO --- AS[Area Supervisor]
    MC1 --- AS
    LRC --- AS
    SO1 --- AS
    AS --- TA1[Typical Areas]
    TA1 --- CS2[Construction Supervisor]
    TA1 --- FE2[Field Engineering]
    TA1 --- P[Planner]
    TA1 --- SO2[Safety Officer]
    S --- OM[Office Management]
    S --- CSC[Cost & Schedule Control]
    OM --- P1[Purchasing]
    P1 --- FA[Field Accounting]
    FA --- TA2[Typical Areas]
    TA2 --- AT[Administration Tech]
    TA2 --- CS1[Clerical Staff]
    TA2 --- N[Nurse]
    TA2 --- LO[Logistics Officer]
    CSC --- MC2[Material Control]
Organizational chart for a Power Plant construction field organization. The hierarchy starts with Quality Control, Resident Management, and Owner at the top. Resident Management oversees Engineering, Construction Inspection, Construction, and Services. Engineering includes Office and Field Engineering leading to Contract Administration. Construction includes Rig Operator, Material Control, Labor Relations Coordinator, and Safety Officer, leading to Area Supervisor and Typical Areas (Construction Supervisor, Field Engineering, Planner, Safety Officer). Services include Office Management (Purchasing, Field Accounting, Typical Areas: Admin Tech, Clerical Staff, Nurse, Logistics Officer) and Cost & Schedule Control (Material Control).

Figure 3
Construction Field Organization Diagram for a Power Plant

Chapter Questions

A1.4

  1. 1. What does ASME stand for? List the ASME Codes used for the design and construction of pressure equipment in Canada.
  2. 2. Briefly describe the steps involved in developing specifications and contracts for new plant installations.
  3. 3. Explain the difference between an engineering study and detailed plant engineering.
  4. 4. How can change orders affect the price of a project? When is the least expensive time to make changes in the design drawings?
  5. 5. List five duties of operations personnel during the construction phase of a new plant construction project.
  6. 6. Explain the difference between the Design – Bid – Build method for plant construction and the Design- Build method.