Our plant safety consultants provide plant safety review by adopting good engineering practices, using various engineering techniques and simulation technologies. Despite the complexity of safety reviews, in general our safety reviews can be broken down into five major steps, namely:
This step involves reviewing the plant designs. Information required to commence this step includes a detailed process descriptions accompanied by process flow diagram (PFD) that contains major equipment, pipes, critical control and mass & energy balance. We also require piping and instrumentation diagrams (P&IDs) that contains all of the equipment, pipes, valves, instrumentation & controls. These P&IDs should be accompanied by functional specifications, safety interlock tables and should exhibit the layers of protection, eg HAZOP, LOPA included in the design. We will also review engineering calculations, datasheets & specifications to ensure these are adequate and appropriate for the intended operations. Finally, we will need to review the plant layout to determine how the equipment will be clustered, the relevant distant employed, the height of equipment and locations of safety equipment. With these information, we will review and benchmark against industry standard, our in-house design checklist and audit the design against relevant standards, regulations and/or government requirements.
Chemical Exposure Index
The chemical exposure index (CEI) was developed by The Dow Chemical Company, used to identify and rank the relative acute health hazards associated with potential chemical releases and its impact to the people in neighbouring plants or communities. This CEI system will provide a method of ranking one hazard relative to another and it is not intended to define a particular design as safe or unsafe. This CEI method is employed for conducting an initial process hazard analysis (PHA), in the distribution ranking index (DRI) calculations, to provide opportunity to make recommendations for eliminating, reducing or mitigating releases and in emergency response planning. The CEI is calculated from five factors: a measure of toxicity; the quantity of volatile material available for a release; the distance to each area of concern; the molecular weight of the material being evaluated; and process variables that can affect the conditions of a release such as temperature, pressure, and reactivity. Hence, we will require chemical and physical properties of all chemicals used in the plant of interest.
Standard Operating Procedures
In this step, we review the standard operating procedures (SOPs), including startup, shutdown, normal, and emergency procedures. The operating procedures should be clear, specific and highlight the limitations of the process, such as temperature, pressure and give the consequences when such limitations are exceeded. In this review, we look for areas such as vague instructions that may result in human errors. We will also select random operators and assess the operator’s ability in executing SOPs. Training records that show operators being equipped with the knowledge to perform risky tasks will also be reviewed. Lastly, we also look at those tasks that should have been incorporated in the design or automated from the outset instead of relying on human actions.
For plant already in operation, we will review accident investigations of previous and relevant incidents that are shared throughout the company and between companies. The purpose is to characterise and understand the weakness of the plant. Apart from review the data stored in either SCADA/PLC or DCS systems, we will also perform statistical process control (SPC) analysis on the plants past performances. Too often, plants simply rely on control system informing when the process variables hit a limit which then triggers actions. Unfortunately, most of such a method devoted far too little attention to variability reduction. A plant in which the process is not stable or has low process capability index is unpredictable and may be unsafe. If the process is centred and has low standard deviation, it will operates within upper and lower limits all the time until a disturbance occurs. And when this occurs, SPC will detect so much earlier before any of the limits are breached giving the control system and/or operators more time to address to the disturbance.
Hazard Identification & Mitigation
In some cases if warranted, in addition to employing the steps outlined above, we may employ computational fluid dynamics (CFD), finite element analysis (FEA) or fluid structural interactions (FSI) simulation technologies. The use of such simulation technologies help to pin-point where the issues are and may further reveal hidden issues. Once we have identified the hazards present in the plant of interest we will develop appropriate recommendations to improve the design and operating procedures to eliminate hazards and prevent accidents. As a plant safety consultant, we will also develop and review the management system to ensure that all of the safety review recommendations are implemented and documented before startup or modifications.
Finally, whilst there are several firms offering plant safety consulting services, we differentiate ourselves from other plant safety consultants in the way we approach a problem. Our standard approach involves safety analysis that goes beyond simply adopting rule-of-thumb guidelines. Whilst rule-of-thumb provides a starting point for most plant safety reviews, in some cases, it may lead to overcompensation. In a nutshell, our conventional plant safety review services are supported by in-house advanced engineering technologies to ensure effective & efficient solutions.
Adiabatic: a thermodynamic process that takes place without heat transfer to or from an external source. When a fluid is compressed adiabatically, there is an increase in temperature of the fluid. Likewise, adiabatic cooling occurs when the pressure of the fluid is reduced without any heat exchange to the surrounding. Adiabatic expansion of a fluid occurs without any heat transfer with the surroundings. Adiabatic compression is the compression of a gas without any transfer of heat to the surroundings. It results in an increase in the temperature of the gas undergoing compression.
Adsorption: a process in which components in gases, liquids, or dissolved substances are selectively held on the surface of a solid. It is used to remove components that may otherwise be harmful if released into the environment or may cause process difficulties further downstream such causing the poisoning of a catalyst. Adsorption usually takes places in fixed beds.
Algorithm: a mathematical method or operation that follows a scheme of calculations or steps designed to be repeated such that the result from one calculation forms the basis of the next. The stage-by-stage computation of the liquid and vapour flows and compositions in a distillation process is based on a defined algorithm.
Aspect Ratio: the ratio of the height to width or diameter of an item of process plant equipment such as a column or storage tank.
Back Pressure: the resistance to a moving fluid to its direction of flow caused by an obstruction, bend, or friction in a pipe or vessel. It is often used to describe the discharge pressure from a pump or compressor. The term often refers to a pressure greater than atmospheric.
Battery Limits: the geographical perimeter that surrounds a processing area and includes process equipment, piping, and associated buildings and structures of a process plant.
Blast Wave: a pressure pulse moving outwards from the site of an explosion. It can be formed by a detonation, a rapid deflagration, or the sudden failure of a piece of process equipment containing a potential energy source that is released at a high rate. The blast pressure is the side-on overpressure and can have destructive effect on buildings and structures.
Block Flow Diagram: a schematic representation of an entire process or major part of a process in which unit operations are symbolically represented as blocks in which process material collectively enters for processing and products leave the process plant. Unlike a process flow diagram, a block diagram has limited information. No information is provided such a flow compositions or details of process conditions within each unit operation. They are useful at the design stage to present how a complex process fits together.
Boundary Condition: used in solving differential equations that are used to describe natural phenomena such as the movement of mass or flow of heat or fluids; they are used to define the boundary of the region under consideration. The boundary condition or value is required to be specified for a solution to be reached. The boundary condition may be a physical entity, such as the velocity of a fluid at a surface, or the concentration of components at a fluid interface.
Boundary Layer: the region between a surface or wall and a point in a flowing fluid over it where the velocity is at a maximum. Within the region, the movement of the fluid flow is governed by frictional resistance. By convention the edge of this region assumed to lie at a point in the flow that has a velocity equal to 99% of the local mainstream velocity. Within the boundary layer, which is laminar in flow, the transfer of heat and mass across it occurs only by molecular diffusion.
Chartered Engineer: a person who is both academically and professionally qualified in engineering. A chartered engineer has a proven ability to work at a high level without supervision to solve complex engineering problems, develop new or existing technologies through innovation, creativity, and change. He or she may be involved in pioneering or promoting advanced designs and design methods, work on new and more efficient products techniques, marketing and construction concepts, engineering services and management methods. A chartered engineer is also engaged in technical and commercial leadership. The person is entitled to use the post-nominal letters CEng after his or her name and will also be member of the institution of engineers.
Chemical Engineering: a branch of engineering that deals with the design, construction, and operation of processes and plant that involve physical, chemical, and biological change for the conversion of raw materials into useful products on an industrial scale. The principal operations include mixing, reaction and separation.
Clean-in-Place (CIP): a fully or partly automated technique used to clean and sanitize closed process equipment after use and before reuse. Used throughout the food and biochemical industries, it avoids the time-consuming process of dismantling equipment and manual cleaning or where cleaning by other means is too difficult due to restricted access. The equipment to be cleaned is equipped with nozzles with supply and return pipes to and from a CIP kitchen. This involves the preparation of the necessary chemicals and wash water and heat exchangers. The cleaning solution is pumped through the equipment often as a spray through the nozzles. A CIP programme typically involves a pre-rinse with water, circulation with a cleaning solution, an intermediate rinse, disinfection and a final rinse with water.
Commissioning: a final and thorough check of an installed process plant or item of equipment to ensure that it is fully operable as intended. All aspects of the process plant or equipment are tested individually and collectively. Prior to commissioning, a site acceptance test is carried out. At the end of the working life of a process, the process plant and its equipment are decommissioned and taken out of service.
Mechanical Engineering: a branch of engineering that is concerned with the study and production of mechanical devices, such as machines, tools and vehicles that are capable of carrying out specific tasks. In process plant design, the role of the mechanical engineers are to perform mechanical engineering designs, mechanical engineering calculations and also to perform stress analysis.
Conceptual Process Design: a work activity performed by engineers at an early stage to evaluate in broad terms the technical feasibility of new and existing processes, as well as process redesigns based on existing feed materials. The work activity examines the thermodynamic feasibility of process routes and the process variables required and assess the broad issues of chemical and process production, which includes information on process costs and material selection. The use of heuristics and process simulation using computers are useful tools to provide rapid information before committing resources to a more detailed design using tools such as computer-aided-design (CAD).
Design Basis: a document that is prepared prior to the design and development of a process plant. It includes the rationale for the design, and includes assumptions and decisions on the options identified for the design as well as the codes, standards, and regulations required in the design. The document is used as the basis for the design, development and construction of the process.
Distributed Control System (DCS): a general name for control systems that are used to control processes characterised by multiple controllers distributed throughout the process and connected by networks for the purpose of communication and monitoring data. They are connected to sensors and valve actuators and can use proportional, integral and derivative control, as well as perform neural network and fuzzy-logic control and be connected to a human machine interface (HMI).
Duty: the power requirement for a machine or item of process plant such as a heat exchanger. The duty of a heat exchanger is dependent on the amount of liquid to be heated, cooled, vaporised or condensed. The duty of a centrifugal pump is dependent on the flow delivered and pressure generated. The SI units for duty are watts or more usually kW or MW.
Emergency shutdown (ESD): the rapid and safe shutdown of a process plant or item of equipment due to a serious deviation in plant operation. Critical valves shut to isolate sections of the process. Other valves may be opened to depressurise vessels or rapidly discharge contents of reactors to quench tanks. Emergency shutdowns may occur due to changes in process plant conditions causing unstable or unsafe operating conditions, a failure in the control system, operator intervention causing unsafe conditions, process plant and pipe failure or some other external event such as electrical storm.
EPC(M): engineering, procurement and construction (construction management)
Feedback Control: a closed-loop method of controlling a plant process in which information about the controlled variable is fed back to the input and compared against a desired value. The difference between the two signals is called the error or deviation. The feedback can be accomplished by a human operator as in manual control or by the use of instruments as in automatic control.
Feedforward Control: a method of process control in which a disturbance is detected before it enters the system for which the controller calculates the required counter-acting disturbance. Process disturbances are measured and compensated for without waiting for a change in the controlled variable to indicate that a disturbance has occurred. Feedforward control is useful where the final controlled variable is not able to be measured. The necessary equations are solved by the controller relating all the process variables, such as steam flow, liquid output temperature etc which are usually designated as the process model. Perfect models and controllers are rare so a combination of feedback and feedforward control is more desirable.
Front End Engineering Design (FEED): is a basic engineering which comes after the Conceptual design or Feasibility study. The FEED design focuses on the technical requirements as well as rough investment cost for the project. It can be divided into separate packages covering various components of the project, can be used as the basis for bidding the Execution Phase Contracts (EPC, EPCM, etc) and is used as the design basis.
HAZOP: an abbreviation for hazard and operability, it is a systematic and structured hazard evaluation technique used to identify the potential failures of process plant or equipment which may otherwise become hazards and present potential operating problems. The aim is to eliminate or minimise the probability of an incident from occurring and the severity of consequence arising from that incident. It uses a multidisciplinary team-based approach to consider what can go wrong, the causes, consequences, frequency of occurrence, measures for prevention and justification of the associated costs of prevention.
Inherently Safe: a plant process or plant system that is able to operate safely without the need for external or auxiliary support. For example, a cooling water system to a plant process that uses heat exchangers of a sufficient duty and that are fed under gravity to ensure removal of heat is inherently safe.
Law of Conservation: states that the total quantity of something or energy remains unchanged within a system although there may be changes occurring within the system such as chemical reactions, changes of states, and other physical, chemical and biochemical changes. This law states that the total amount of material or energy within the system boundary neither increases nor decreases. This law forms the basis of material and energy balance for a process.
PID Control: the modes of control employed to control plant processes or part of a plant process. The three basic modes of control are proportional control, integral control and derivative control.
Piping & Instrumentation Diagram (P&ID): a schematic representation of the interconnecting pipelines and control systems for a plant process or part of a plant process. Using a standard set of symbols for plant process equipment and controllers, it includes the layout of branches, reducers, valves, equipment, instrumentation and control interlocks. They also include process equipment names and numbers; process piping including sizes and identification’ valves and their identification’ flow directions, instrumentation and designations; vents, drains, sampling lines and flush lines. P&IDs are used to operate the process system as well as being used in plant maintenance and process modifications. At the design stage, they are useful in carrying out safety and operations investigation such HAZOP.
Plant: major equipment and machinery used in industrial processes. A process plant is the entire industrial process or factory in which raw materials are converted to products through chemical, physical or biochemical transformation.
Plant Layout Study: an analysis of the different possible physical configurations for an industrial process plant. Due to the complexity of modern plants and manufacturing facilities that involve complex operations, the study typically involves the physical space and proximity of vessels and equipment, materials handling, piping and auxiliary equipment, utilities and services, communications systems, emergency systems, structural and architectural considerations and general site work.
Upstream: a stream of material for processing that has not yet entered the process for chemical transformation in reactors etc. The stream of material that has already been transformed is called Downstream.
Yield: the amount of a product that is recovered from a process or chemical reaction. It is usually expressed as a fraction or a percentage based on the raw materials used or as a ratio of the final product to the starting materials without considering any side reactions.
AUSTRALIA SINGAPORE ASIA PACIFIC REGION
We provide engineering services to industries such as building & environment, chemical & petrochemical, food & beverage, renewable energy and water & wastewater. We differentiate ourselves in the way we approach a problem. Our standard approach involves in-depth analysis that goes beyond simply adopting rule-of-thumb guidelines. Whilst rule-of-thumb provides a starting point for most design works, it has the tendency to overdesign which eventually leads to higher overall fabrication costs. In a nutshell, our engineering consultants are supported by in-house simulation technologies to ensure effective & efficient deliverables. Our scope of engineering services are:
- Plant Engineering Design
- Infrastructure Protection Design
- Plant Safety Review
- Modular Plant Design
Our engineering consultants perform independent safety reviews of process plants which involves a holistic approach that covers the entire spectrum of the process plant whilst employing various tools and technologies. Despite the complexity of safety reviews, in general our safety reviews can be broken down into five major steps, namely:
- Engineering design which involves reviewing the plant designs particularly on the safety featured
that have been incorporated into the design
- Chemical exposure index (CEI) which we use to identify and rank the relative acute health hazards
associated with potential chemical releases and its impact to the people in the neighbourhood
- Review of the standard operating procedures (SOPs), including startup, shutdown, normal, and
emergency procedures. We look out for those that my lead to human errors
- For plant already in operation, we will also review past plant performances using a combination of
control system data log and statistical process control (SPC)
- Finally, we will identify the hazards present in the plant of interest, develop appropriate
recommendations to improve the design and operating procedures and eliminate hazards
We provide infrastructure protection design to defend critical infrastructure and most importantly human lives from being attack by extreme loading. Through an in-depth analysis of material, and structural behaviour (including large deformation, material fragmentation, solid-solid, gas-solid and fluid-solid interactions), our consultants are able to predict how building structures respond to threats such as explosive blast wave and fragment attack (including directed ballistic attack). The scope of work in which our security & blast consultants operate include:
- Threat, consequence, vulnerability assessment
- Quantitative risk assessment which considers site, architectural and structural resilience of assets
- Blast and fragment effects analysis supported by in-house explicit nonlinear dynamics simulation
- Structural resilience study and recommendation of options to mitigate risks
- Development of a comprehensive security and blast protection plan
- Cost and benefit study of each option presented
- Security by design incorporated in new assets or retrofitting of existing assets
- Incremental protection or one-off implementation for existing assets
We provide turnkey services which include engineering design, fabricate, global delivery and commissioning of modular units. Our engineering consultants experience includes:
- In-house engineering design capability and fabrication within our state-of-the-art facilities
- Fabricating high quality packages under more stringent industry standards and control
- Experienced in fabrication of mobile skids as well as 20 to 40-foot containerised units
- Modular assembly includes fabrication of steel structure and pipe spools
- Complete assembly with instrument, PLC cabinet, electrical wiring & junction box and insulation
- Performing factory commissioning and acceptance testing prior to delivery
- Renewable energy: by-product conversion, effluent gas and biomass conversion packages
- Water: desalination, water conditioning and ballast water treatment system
- Oil/gas: 2/3 phases separators, oil treater, sand removal and slug handling packages
- Sterile: pharmaceutical and food manufacturing clean-in-place packages
- Skids and containerised units are available to be shipped globally
PLANT ENGINEERING DESIGN
As engineering consultants, we provide multidisciplinary plant engineering design supported by our in-house simulation consultants across many industries particularly in the functional areas of:
- Applied chemical and process engineering expertise
- Conceptual design and front end engineering design (FEED)
- Detailed process system integration design suitable for construction
- Process dynamic system modelling and simulation using ASPEN HYSYS
- Hydraulic calculations, sizing of PRVs and studies of complex piping network
- Mechanical engineering design supported by 2D drafting and 3D geometrical modelling
- Power piping designed to ASME B31.1, B31.3, AS 4041 and pipe stress analysis using CAESAR II
- Process control automation, electrical and instrumentation systems design
- Preparation of design, procurement and construction packages
- Procurement, inspection and receiving of equipment on behalf of clients
- Plant construction management to ensure the plant is constructed as per design intention
- Commissioning support and plant performance optimisation using DOE, SPC and Pinch Analysis