INSTRUMENTATION DESIGN & DETAIL ENGINEERING
Introduction to Detail Engineering
Instrumentation Detailed Engineering (IDE) is a study which defines every technical and non technical aspects of project development. IDE follows Basic Engineering (BE) and Front End Engineering Design (FEED). It contains in detail diagrams and drawings for construction, civil works, Instrumentation, Control System, Electrical Facilities, Management of Suppliers, Schedule of Activities, Costs, Procurement of Equipment, Economic Evaluation and also Environmental Impacts before starting of construction of a project. Instrumentation detailed engineering found to be the best method for plant commissioning and plant maintenance.
Every industrial sector there is requirements of number of instruments and control systems for automation. But every instrument has its life-period, once it crossed the instrument starts giving faulty readings which results in hazardous situations. For this we need to be in process of continuous maintenance activities or need to manufacture a new one and install. So, either to begin a new project or to make changes in existing one basic design steps are followed which includes design of Instrumentation Index Sheet (IDS), Data Sheet (DS) also know as Specification Sheets, Loop Wiring Diagram (LD), Hook-up Drawing(HD) also known as Installation Drawing.
Design Concept - Piping & Instrumentation Diagram
This is complete overview of the plant where information of instruments installed on pipelines and their connections to control systems are shown. It has technical information as plant number, instrument tag numbers, line numbers, line elevation details, pipe line numbers are shown.
Instrument Index Sheet
It is a list of instruments within a plat. It is designed at the start of the project and consider as live document which should kept updated even though the plant has been operated. This sheet is revised if there is any modification which impact to additional, removal or resetting of the instrument. In this sheet information is listed as Tag Number, Loop Number, Type of instrument, Location, Service Description, P&ID Number, Line number and Equipment number, I/O types, Control System details.
Instrument Data Sheet
This is design with specification and information of instrument device. Process data as fluid type, fluid state, design pressure, design temperature, operating temperature, flow rate, density, viscosity, and specific gravity are listed. Process Data can be obtained from Heat and Material Balance document. Once Data sheets are designed it is attached to requisition which to be sent to several vendors. Vendors will offer their quotation with various model and manufacturer among the offers. It is instrumentation engineer’s responsibility to evaluate all quotation and determine which order is technically accurate.
It shows typical installation of instrument in a correct manner so that instrument operates properly. Is indicates tubing slope, position of instrument in reference to process tapping point, scope break between instrument vs. piping. There are two types of hook-up drawings, one is process hook-up and second is pneumatic hook-up. Requirement of Bulk material could be summarized and tabulated in a document called Material Take Off.
Loop Wiring Diagram
Loop wiring diagram shows detailed information of instrument connections from one point to control system. It could be connection between, Field instrument to control system, Signal from control panel to control system, Signal from MCC to control system, Signal from one control system to another.
Safety - Interlock
As per hazardous conditions signal is given to Programmable Logic Controller (PLC). These signals are categorized as High / Low or High-High / Low-Low.
Emergency shutdown valve (ESD)
It is an actuated valve designed to stop the flow of hazardous fluid upon the detection of dangerous event. This provides protection against possible harm to people, equipment or the environment. Shutdown valves form part of safety instrument system.
Pressure safety valve
It is it term used to describe relief device on a compressible fluid vessel. For such valve the opening is sudden. When the set pressure of the valve is reached, the valve opens almost fully. It is purposely installed in bypass lines for safety.
Results and Discussion
Instrumentation Detailed Engineering (IDE) found to be best method for plant commissioning and maintenance activities. IDE provides great platform to each project department like mechanical, civil, electrical, instrumentation, computers (for analysis) to execute project effectively with strong interactions within them. IDE has strong impact on the overall project cost. IDE ensures optimum quantities, work-volumes, constructability, operability and maintainability and safety of power and process industry plant.
SmartPlant Instrumentation (INtools) reduces the effort needed to manage instrumentation assets. This in turn reduces the risk and cost of the overall plant information challenge. SmartPlant Instrumentation allows you to manage your plant instrumentation by means of a "single source of truth" - reducing the time to get the right information for maintenance jobs. Because any changes in your instrumentation assets will be correctly reflected in all information deliverables (all your datasheets, diagrams and reports) - fewer decisions will be made using wrong or conflicting information.
Career as Instrumentation Design Engineer
Instrumentation Design Engineer support the instrument and control equipment both onshore and offshore to ensure that it remains efficient and productive. Instrument Engineers can work for a range of companies including the Operators who own or manage production installations, major Engineering Contractors and Engineering Consultancies. Instrument Engineers will interact as part of a larger engineering team, using knowledge and expertise from their own experience, as well as that of others. This will also involve working closely with other engineering disciplines (such as electrical, mechanical, process and construction engineering), to ensure the highest quality of work. Typically based in onshore offices, Instrument Engineers will undertake regular visits to production installations.