Технологическая схема и схема КИПиА, Схема трубопроводов и КИПиА, Схема трубной обвязки и КИПиА (Piping & Instrumentation Diagrams) символы и обозначения оборудования на технологических схемах.
Технологическая схема и схема КИПиА, Схема трубопроводов и КИПиА, Схема трубной обвязки и КИПиА (Piping & Instrumentation Diagrams) символы и обозначения оборудования на технологических схемах.
В РФ виды и типы технологических схем определяются Единой системой конструкторской документации (ЕСКД). «Схемы. Виды и типы. Общие требования к выполнению» Там их десятки комбинаций. Англосаксы и прочие немцы широко пользуются т.н. Piping and instrumentation diagram (P&ID) — "Схема трубопроводов, трубопроводной арматуры, насосов и КИПиА" — которую определяют как графическую иллюстрацию некоторого технологического процесса, включающую в себя трубы и их соединения, сосуды и аппараты, регулирующую и запорную арматуру, устройства КИПиА и прочее оборудование технологической системы (процесса). P&ID это схематический чертеж, который показывает принципиальное устройство системы управления технологическим процессом — т.е абсолютно критически важные данные для проектирования, строительства, монтажа и ремонта технологической системы..
Этапы где используется P&ID (Схема трубопроводов, трубопроводной арматуры, насосов и КИПиА):
- Проектирование и компоновка технологического процесса (системы)
- Спецификация оборудования
- Разработка алгоритмов и схем управления
- Анализ эксплуатационных опасностей и работоспособности технологического оборудования (HAZOP – hazard and operability study)
- Монтаж и/или демонтаж системы
- Схемы и регламенты запуска и остановки системы, а также производственные регламнты и процедуры
- Обучение и переобучение операторов технологического процесса (системы)
- Обслуживание и модификации системы (процесса)
Также эти схемы (P&ID) широко используются как основа графического интерфейса в компьютерных системах управления технологическими процессами HMI (human-machine interface = HMI-интерфейс = человеко-машинный интерфейс).
Символы оборудования в диаграммах и схемах P&ID
Существуют стандартные и вполне общепринятые знаки и символы для обозначения оборудования на этих схемах. Важно понимать, что у этих символов нет "правильного" масштаба и/или каких-то требований к размерам. Они используются только лишь для того, чтобы указывать тот или иной компонент схемы. Для более точного указания на тип представляемого оборудования вместе с этими символами используются подписи, буквы и цифры. Кроме того, такая диаграмма не отражает фактического месторасположения элементов схемы и/или близость одних элементов к другим. Идея использования этих схем — только лишь подробно проиллюстрировать технологический процесс.
Символы клапанов, кранов, задвижек, вентилей и другой трубопроводной арматуры для P&ID
Образующий символ для проходного = двухходового = 2-way клапана — это два треугольника, соприкасающиеся вершинами (см. рисунок ниже). Трубопроводы изображаются в виде прямых линий, соединенных с обеими сторонами символа клапана. Различные типы линий обозначают различные типы труб, шлангов, подводок и т.п. На примере ниже — сплошные линии — обозначают твердые (негибкие) трубопроводы. Обычно, для унификации, трубы на схемах изображают только горизонтальными и вертикальными линиями. Направление потока указывается в месте где труба переходит в другой символ и на каждом повороте трубопровода (как помним, повороты — это 90°
Тип трубопроводной арматуры по конструкции.
Тип крана, клапана, задвижки, вентиля затвора и т.д. указывается значком в центре образующего символа. Ниже — символы и знаки для наиболее распространённых типов трубопроводной арматуре, а именно: шаровой кран, затвор поворотный, пробковый, седельчатый, мембранный клапаны, задвижки, затворы, вентили.
Ниже, во-первых, значок (символ) любой проходной = двухходовой = 2-way трубопроводной регулирующей, запорной или дросселирующей арматуры. Для многоходовых (таких, как трехходовые и четырехходовые) кранов, клапанов и т.п. используется аналогичный символ, в котором используется по треугольнику на каждый порт арматуры.
Знаки для трехходовых (3-way) и четырехходовых (4-way) шаровых кранов могут содержать дополнительные детали, которые уточняют тип прохода шара — либо сверловка “T” либо сверловка “L”. Кроме того с помощью стрелок может быть указано направление потока "по умолчанию", т.е. в случае обрыва или отключения питания привода.
Существет огромное множество различных типов трубопроводной арматуры, некоторые символы с пояснениями — ниже:
Тип привода.
Тип привода указывается с помощью линии, выходящей из центра крана (клапана. ) с небольшим символом, часто содержащим еще буквы. Ниже — несколько примеров символов шаровых кранов с различными типами приводов:
Позиция клапана по умолчанию = позиция клапана с приводом при обрыве питания = Fail-Safe Position
Если у привода есть некая позиция по умолчанию, то ее обозначают стрелочкой. Либо, если при обрыве питания клапан закрывается — то это позиция обозначается "FC" = fail closed или "NC" = normally closed или "НЗ"=Нормально Закрыт, противоположная "FO" = fail opened или "NO" = normally opened или "НО"=Нормально открыт.
Типы присоединений трубопроводной арматуры к трубопроводу
В общем, присоединение к трубопроводу всега обозначается линиями, выходящими из символа крана. Тип присоединения к трубопроводу может быть при необходимости дополнительно определен различными другими способами. Фланцевое присоединение обозначается (рисунок ниже) перпендикулярными трубе отрезками на конце трубопровода, которые парралельны концам крана с небольшим промежутком между краном и этими отрезами. Это говорит в первую очередь о том, что кран можно удалить не разрезая трубопровод. Полунеразборное резьбовое соединение указывается небольшими полыми внутри кружочками. Неразборное сварное присоединение указывается малыми квадратами. Если это сварка враструб (Socket Weld) то квадрат изображается полым (пустым внутри).
Стандартизация
Международное общество автоматизации (ISA: www.isa.org) определяет самые распространенные стандарты для технологических схем и схем КИПиА (P&IDs). Основной стандарт это ANSI / ISA-5.1 "Instrumentation Symbols and Identification" и его можно приобрести тут ISA website, хотя и бесплатных вариантов в сети полно.
Невзирая на то, что казалось бы стандарт строго определяет используемые символы, на практике Вы постоянно будете встречать массу "народного творчества". Вы также обнаружите очевидные несоответствия в обозначении некоторых типов трубопроводной арматуры в различных библиотеках, компаниях, а также в зависимости отрасли промышленности. По факту это не особо критично, поскольку все элементы схемы также описываются текстом, технологическим номером (место в схеме), собственным наименованием (уникальное наименование), а также присутствуют в спецификации материалов и оборудования, которая обязательно прилагается к схеме. Если Вы подходите достаточно ответственно к своей схеме Ваша P&ID схема будет полезна и понятна всем, кто с ней работает.
Трубопроводы, трубы, рукава, шланги (технологические трубопроводы):
Технологические трубопроводы (process lines) это общее обозначение для всего, в чем течет рабочая среда. Различные типы трубопроводов указываются различными символами. На законченной технологической схеме (P&ID) каждый трубопровод будет подписан собственным технологическим номером. Например — 150-67P00-2299-115101-N. Этот номер указывается либо параллельно линии на схеме, либо на выноске, которая упирается в линию схемы. Номер обычно включает в себя информацию о размере, требованиях к качеству, изоляции трубопровода и т.д. Различные компании используют различные структуры этих данных, но в целом все они содержат одну и ту же информацию. Линии, обозначающие технологические трубопроводы, исполняются толще, чем линии, которые обозначают сигналы управления (пневматические, электрические, цифровые. )
Различные символы технологических трубопроводов:
Существует два основных способа указать на схеме тот факт, что трубопроводы пересекаются, но не соединяются. Следует либо использовать небольшую "горку", чтобы показать один трубопровод, проходящий над другим, либо прервать одну из линий, как указано ниже. Это не является схемой реального физического расположения труб, они вообще могут не пересекаться в реальной системе, это исключительно способ указывать трубопроводы раздельными, если они встретились на схеме.
Обозначение сигналов управления:
Для указания сигналов управления, которые отвечают за обмен данными между различными элементами технологической системы, также используются собственные символы.
Различные символы сигналов управления:
Сосуды, емкости и баки = Vessels
Насосы, вентиляторы, компрессоры = Pumps, Fans, & Compressors
Этот список можно продолжать и продолжать. Существуют сотни символов, которые соответствуют всем возможным компонентам технологического процесса. Теплообменники, кулеры, котлы, бойлеры, фильтры и т.д. и т.п.
КИПиА = контрольно-измерительные приборы и автоматика (датчики, расходомеры, измерители, детекторы, сигнализирующие реле, преобразователи и т.д.)
КИПиА (по буржуински — instrumentation) котнтрольно-измерительные приборы и автоматика — это совокупность устройств измерения, контроля, регистрации и управления. Для символов КИПиА принят несколько другой подход — эти устройства обозначают так называемым "пузырем" — квадратом, кругом или там гексагоном, октагоном.
Квадратный символ соответствует многоканальному (многопользовательскому) экрану. Такой экран показывает информацию из нескольких источников или управляет несколькими устройствами. Внутри квадрата может быть либо круг, либо ромб ("diamond")
Круг указывает на тот факт, что это устройство по умолчанию в основной системе управления (Basic Process Control System)
Такой тип выносного символа используется для описания функционирования полевого оборудования, такого как клапаны. Буквы и цифры из символа описываются в легенде отдельно.
Существуют дополнительные простые символы (различные горизонтальные линии), которые определяют где находится устройство и показывают насколько данные с этого устройства доступны оператору:
Цифры и буквы внутри символов.
Внутри символов в качестве дополнительных обозначений-уточнений используются и буквы и цифры для указания измеряемого или регистрируемого параметра (расход, давление, температура, уровень), а также описания выполняемой функции. Типичные функции устройства в системе таковы — отображение параметров, запись, передача данных, управление. Ниже — несколько примеров и список наиболее используемых символов в технологических планах и схемах:
Каждый элемент схемы маркируется символам (от 2х=до 5-ти):
- 1-я буква определяет измеряемую величину: F = расход (flow rate), P = давление (pressure), T = температура, L = уровень (level)
- 2-я буква это уточнение: D = дифференциальная величина (differential), R= относительная величина (ratio). пропускаем, если не нужно это уточнение
- 3-я буква указывает назначение устройства: A = авариный сигнал (alarm), R = (запись) record, I = индикатор, G =датчик (gauge)
- 4-я буква — функционал: C = контроллер, T = передатчик (transmit), S = выключатель, переключатель (switch), V = трубопроводная арматура (valve)
- 5-я буква — уточнение функции: H = верхнее, высокое, превышение (high), L = нижнее, низкое, снижение (low), O = открыто (open), C = закрыто (closed). пропускаем, если не нужно это уточнение
Это обозначение дополняется номером контура управления технологической схемы. Для примера — FIC045 обозначает Расхода Показывающий Контроллер (расходомер с выходным сигналом) = Flow Indicating Controller в контуре 045. Этот номер частенько называют "тэгом" ("tag” identifier) устройства — номер указывающий на местоположение и назначение устройства. Ниже — несколько примеров полных символов для некоторых устройств в том-же контуре системы:
Таблица — Обозначения, используемые в технологических схемах (P&IDs) согласно ISA standard ISA-S5-1
Первая буква
Не первая буква
Вкратце, это все + существует огромное количество компьютерных программ для создания P&ID, ищите и пробуйте.
What are Piping & Instrumentation Diagrams
P&IDs can seem mysterious, but don’t have to stay that way thanks to our intuitive P&ID software. Learn the what, why, and how of everything Piping & Instrumentation Diagrams in this comprehensive guide.
Want to make a P&ID of your own? Try Lucidchart. It's quick, easy, and completely free.
What is P&ID?
A piping and instrumentation diagram, or P&ID, shows the piping and related components of a physical process flow. It’s most commonly used in the engineering field.
Function and purpose of P&IDs
P&IDS are foundational to the maintenance and modification of the process that it graphically represents. At the design stage, the diagram also provides the basis for the development of system control schemes, like Hazard and Operability Study (HAZOP).
For processing facilities, it’s a graphic representation of
- Key piping and instrument details
- Control and shutdown schemes
- Safety and regulatory requirements
- Basic start up and operational information
When to use P&IDs and who uses them
P&IDs are a schematic illustration of the functional relationship of piping, instrumentation and system equipment components used in the field of instrumentation and control or automation. They are typically created by engineers who are designing a manufacturing process for a physical plant.
These facilities usually require complex chemical or mechanical steps that are mapped out with P&IDs to construct a plant and also to maintain plant safety as a reference for Process Safety Information (PSI) in Process Safety Management (PSM). If something does go wrong, reviewing the P&ID is usually a good place to start. P&IDs are invaluable documents to keep on hand, whether they’re used to streamline an existing process, replace a piece of equipment, or guide the design and implementation of a new facility. With the record they provide, changes can be planned safely and effectively using Management of Change (MOC).
P&IDs are used by field techs, engineers, and operators to better understand the process and how the instrumentation is interconnected. They can also be useful in training workers and contractors.
What are P&IDs all about?
P&IDs play an essential role in the process engineering world to show interconnectivity, but they don’t necessarily include specifications. Specifications are usually provided in separate documents. But they are incredibly useful in many ways, including:
- Evaluate construction processes
- Serve as a basis for control programming
- Develop guidelines and standards for facility operation
- Produce documents that explain how the process works
- Provide a common language for discussing plant operations
- Create and implement philosophies for safety and control
- Design a conceptual layout of a chemical or manufacturing plant
- Form recommendations for cost estimates, equipment design, and pipe design
What’s the difference between a process flow diagram (PFD) and a piping & instrumentation diagram (P&ID)?
Instrumentation detail varies with the degree of design complexity. Simplified or conceptual designs are called process flow diagrams (PFDs). A PFD shows fewer details than a P&ID and is usually the first step in the design process–more of a bird’s eye view. More fully developed piping and instrumentation diagrams (P&IDs) are shown in a P&ID.
What are the limitations of P&ID?
Since P&IDs are graphic representations of processes, they have some inherent limitations. They can’t be relied on as real models, because they aren’t necessarily drawn to scale or geometrically accurate. There’s also no generally accepted universal standard for them, so they may look different from company to company—or even within the same company—based on internal standards, the type of software system being used, and the preferences of the creator. That’s why it’s important to design and review the documentation that gets down to the real nuts-and-bolts of support documents.
A look at P&ID support documents
Because P&IDs are schematic overview graphics, you need documents to clarify the details and specifications. Here are some of them:
- Process flow drawings (PFDs). P&IDs originate from PFDs. A PFD is a picture of the separate steps of a process in sequential order. Elements that may be included are: sequence of actions, materials or services entering or leaving the process (inputs and outputs), decisions that must be made, people who become involved, time involved at each step and/or process measurements.
- Piping material specifications (PMS). Here’s where you find details about materials of construction, gaskets, bolts, fittings.
- Equipment and instrumentation specifications (EIS). Standards and details too extensive to fit into the P&ID are included in the EIS including Scope, Standards, Codes and Specifications, Definitions and Terminology, Materials of Construction, Design Basis, Mechanical/Fabrication, Guarantees, Testing and Inspection, Documentation and Shipping.
- Functional Requirement Specification (FRS). How the plant or system operates is detailed in the FRS. It includes the Functional Description, Communication, and Scope Definition of the process.
What should a P&ID include?
While there are no exact standards for the way P&IDs should be drawn, there have been standards suggested by the Process Industry Practice (PIP), a consortium of process industry owners and engineering construction contractors who serve the industry. PIC001: Piping and Instrumentation Diagram Documentation Criteria details what a P&ID should contain:
- Mechanical equipment with names and numbers
- All valves and their identifications
- Process piping, sizes and identification
- Miscellaneous — vents, drains, special fittings, sampling lines, reducers, increasers and swagers
- Permanent start-up and flush lines
- Flow directions
- Interconnections reference
- Control inputs and outputs, interlock
- Seismic category
- Interfaces for class changes
- Quality level
- Annunciation inputs
- Computer control system input
- Vendor and contractor interfaces
- Identification of components and subsystems delivered by others
- Intended physical sequence of the equipment
- Equipment rating or capacity
What should a P&ID not include?
The nitty-gritty details can be better left to support documents. You want to create P&IDs that create clarity, not clutter. For that reason, you will want to omit:
- Instrument root valves
- Control relays
- Manual switches
- Primary instrument tubing and valves
- Pressure temperature and flow data
- Elbow, tees and similar standard fitting
- Extensive explanatory notes
How to create a P&ID
If you use software to create your P&IDs, there are some basic steps to follow:
- Create and check an equipment list. Use the symbols within the library after you’re sure of your list.
- Connect pipes and equipment, then review the details with a trusted colleague. Walk through the process several times and search for inefficiencies.
- Share with collaborators.
For more details and how-to, go to the P&ID Tutorial.
Organization fundamentals of P&ID
As a keystone document, the P&ID should be organized in a logical progression. While many—or most—companies set their own standards for P&ID organization, it can be thought of as chapters of a book or scenes from a movie that interconnect to tell your engineering process story. It should provide a concise and easy-to-understand illustration of all the equipment to be included in the process flow, alert information around hazard, safeguards and potential faults so that errors can be minimized or eliminated. It will help support the development of operating and maintenance procedures. As a storyboard of the process, it’s a way to see that changes can be made safely and effectively using Management of Change.
Different types of P&ID diagrams
There are as many different styles and types of diagrams as there are companies and products. Here are two examples:
This example shows a fluid flow system and defines mechanical and design configurations that are in place.
A P&ID of 3-phase separator vessels, which are components used in the oil and gas industry to separate various liquids that flow from wells.
Diagramming is quick and easy with Lucidchart. Start a free trial today to start creating and collaborating.
P&ID symbols and notations
One area of P&IDs that is standardized are the instrumentation symbols, the key to being able to understand P&IDs. Instrumentation symbols appearing on diagrams adhere to ANSI/ISA’s S5.1-1984 (R 1992) standards. Sticking to the Instrumentation, Systems, and Automation Society (ISA) S5.1 Instrumentation Symbols and Identification standard ensures a consistent, system independent means of communicating instrumentation, control, and automation intent so everyone understands.
ISA S5.1 defines four graphical elements—discrete instruments, shared control/display, computer function, and programmable logic controller—and groups them into three location categories (primary location, auxiliary location, and field mounted).
- Discrete instruments are signified by circular elements. Shared control/display elements are circles surrounded by a square. Computer functions are indicted by a hexagon, and programmable logic controller (PLC) functions are shown as a triangle inside a square.
- A single horizontal bar across any of the four graphical elements means the function resides in the primary location category. A double line indicates an auxiliary location, and no line places the device or function in the field. Devices located behind a panel-board in some other inaccessible location are shown with a dashed horizontal line
- Letter and number combinations appear inside each graphical element and letter combinations are defined by the ISA standard. Numbers are user assigned and schemes vary with some companies use of sequential numbering. Some tie the instrument number to the process line number. Others may choose to adopt unique and sometimes unusual numbering systems.
- The first letter defines the measured or initiating variables. Examples inlcude Analysis (A), Flow (F), Temperature (T), etc. with succeeding letters defining readout, passive, or output functions such as Indicator (I), Record (R), Transmit (T), and so forth.
Here are some examples of P&ID symbols. You can review a full overview of all P&ID symbols included in Lucidchart if needed.
Equipment
Equipment is comprised of miscellaneous P&ID units that don't fit into the other categories. This group includes hardware like compressors, conveyors, motors, turbines, vacuums, and other mechanical devices.
Piping
A pipe is a tube that transports fluid substances. Piping can be made of various materials, including metal and plastic. The piping group is made up of one-to-many pipes, multi-line pipes, separators, and other types of piping devices.
Vessels
A vessel is a container that is used to store fluid. It may also alter the characteristics of the fluid during storage. The vessels category includes tanks, cylinders, columns, bags, and other vessels.
Heat exchangers
A heat exchanger is a device that's designed to efficiently transfer heat from different areas or mediums. This category includes boilers, condensers, and other heat exchangers.
Pumps
A pump is a device that uses suction or pressure to raise, compress, or move fluids in and out of other objects. This section is comprised of both pumps and fans.
Instruments
An instrument is a device that measures—and sometimes controls—quantities such as flow, temperature, angle, or pressure. The instruments group houses indicators, transmitters, recordings, controllers, and elements.
Valves
A valve regulates, directs, or controls the flow of a fluid by opening, closing, or partially obstructing passageways in a piping system. This category includes rotameters, orifices, and other types of valves.
You’ll find many more of the common shapes and symbols at Lucidchart P&ID Symbols Legend .
What to look for in P&ID diagram software
There are lots of software tools that enable diagramming. But there are criteria that can make P&ID more efficient: ISA standards adherence, ease of use, ability to integrate into other productivity tools, and most importantly in many cases, the power to collaborate with other team members and departments.
Why is Lucidchart right for your P&IDs?
Lucidchart online flowchart maker is used by people around the world to create P&ID and many other types of diagrams and charts. Because of its intuitive user interface and collaborative features, it is the most popular online Visio alternative. Lucidchart was designed to be both intuitive and powerful to meet the needs of engineers, so projects go smoothly for everyone involved in your P&ID process:
- Simple to use: Detailed diagramming options for fast, precise drawing. And since Lucidchart's symbols are based on the ISA S5 standards, your P&IDs will be welcome in any professional context. Engineers and technicians will appreciate Lucidchart's streamlined online P&ID software. Drag-and-drop simplicity, keyboard shortcuts, and interactive elements make Lucidchart the perfect P&ID creator.
- Fully integrated: Diagramming can fit seamlessly into your current workflow. Since Lucidchart is integrated with G Suite, Google Drive, JIRA, Atlassian, and other top productivity tools, all you need to do is plug and play.
- Enables collaboration: Standard download options—PNG, JPG, PDF, VDX—or save the diagram to a secure webpage. Your diagram can also be embedded on any HTML website. Our cloud-based tool allows collaborators to work together for detailed, accurate work. To save time and energy, Lucidchart allows you to sketch out diagram requirements early on. Use our real-time collaboration—including group chat and commenting—while working with clients, engineers, and designers.
- Visio import/export: Is your team still using Microsoft Visio to create piping and instrumentation designs? We offer the same shape set, but with a much friendlier price tag. Just import your old Visio documents into Lucidchart—they’ll become instantly editable.
A use case shows the value of Lucidchart—for everyone
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Additional Resources
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Basics of P&ID (piping and instrumentation diagram)
A Process and Instrumentation Diagram (P & ID) shows the process flow and interconnection of process equipment which is used control a process. The P & ID includes every mechanical aspect of the plant except stream flows, pipe routing, pipe lengths, pipe fittings, supports, structure & foundations.
A P&ID provides information to begin planning for construction of plant. There are different Sets of symbols are used to depict mechanical equipment, piping, piping components, valves, drivers and instrumentation and controls. A P&ID digram contains following information regarding the equipment: size, rating, throughput, and utility usage.
Uses of P & ID:
- Used for planning & construction of plant
- Used to operate the process
- Used for maintenance & modification of the process
- Used by mechanical technicians & safety personnel
- Used for HAZOP study of plant
- The controlled document formally issued at various stages of the project
How to create a P&ID?
Different software is available to create or draw a P&ID diagram. Only a few steps to follow to create a p&id diagram, but one who does it should know well knowledge about the plant process.
- Create the full list of instruments and equipment required for the process. Check the symbols used for each equipment from the library.
- Arrange all equipment in the process order and do the connection.
- Then review the details with a trusted colleague. Walk through the process several times and search for inefficiencies.
- Discuss with the collates
P&ID symbols and abbreviations:
Process lines:
Instrument Bubbles:
Process equipents:
Valve types:
VS — Gate Valve
VD — Globe, Needle or Angle Valve
VR — Plug Valve
VB — Ball or 3-way Plug Valve
VDR — Check Valve
VF — Butterfly Valve
VM — Diaphragm Valve
VP — Piston Valve
Temperature:
These symbols are represented in the respective instrument bubbles:
TE = Temperature sensing element
Th = Thermometer Indicator
TRC = Recorder-controller
TR = Recorder
Pressure:
These symbols are represented in the respective instrument bubbles:
PC = Controller
PI = Indicator
PIC = Indicator-controller
PR = Recorder
Level:
LC = Controller
LG = Glass
LI = Indicator
LR = Recorder
FC = Controller
FE = Test orifice plate
FI = Indicator
FR = Recorder
How to read a P&ID?
Each instrument in the process and their connections are drawn in a P&ID diagram. Thus the process is simply described in the diagram. Specification of the instruments is written with the instrument symbol. The specification of the line is code in the line or above the line as shown in the below picture:
Area Code:
01 : Urea
02 : Reforming Section
03 : CO2 absorption Section
04 : Synthesis gas compression
05 : Ammonia Synthesis
06 : Steam Generation
07 : Power Generation
08 : CW circulation
Fluid Type:
KS : Very High-Pressure Steam
HS : High-Pressure Steam
LS : Low-Pressure Steam
P : Process Fluid
IA : Instrument Air
UA : Utility Air
UN : Utility Nitrogen
Material:
1 : Carbon Steel
3 : Austenitic Stainless Steel
4 : Reinforced Thermal Resin Pipe
5 : Si Killed Carbon Steel or CrMo steel
6 : Ferritic Alloy Steel
7 : Cast Steel
8 : Austenitic SS or Ferritic Alloy Steel
9 : Urea Grade SS
Material Rating:
1 : 150#
3 : 300#
5 : 600#
6 : 900#
7 : 1500#
8 : 2500#
9 : Special
Insulation Specification:
N : Not Painted /Insulated
PP : Personnel Protected
S : Internal Treated/External Painted
A : Internal Treated, External coated
B : External Coated
E : Electric traced
F : Cold Insulated
I : Hot Insulated
T : Steam traced
V : External painted
W : Jacketed
What is P&ID? (Piping and Instrumentation Diagram)?
P&ID (Piping and Instrumentation Diagram or Drawing) is a technical drawing used in process engineering. It represents all details of the chemical process at processing plants, such as oil refineries, food processing plants, cement plants, pharmaceutical manufacturing facilities, or other plants where raw material is chemically or mechanically turned into ingredients or finished products.
Everyone involved in the design, construction, management, operations, or maintenance of a process plant, will have to work with a P&ID at some point. Therefore, everyone should either know how to read these drawings or have a good graphic interface or simulation software to access them, as they are basically a representation of how the processing facility works.
How To Create a P&ID
Back in the day, designers, constructors, engineers, managers, and staff of process facilities had to work with multiple hand-drawn P&IDs. Those drawings would all need to be updated whenever the parameters of the process changed – be it at the design and construction stage, or during plant operation, or when some equipment was modernized. Even after CAD software was introduced, managing an archive of all these drawings took hours of very meticulous work and strict procedures.
Today, the way we use and manage P&IDs is much more intelligent and faster. Not only are there dedicated P&ID applications and database systems out there, but with an experienced developer team, you can create a custom, collaborative tool that guides you through design and budgeting, safety regulations, and provides a live simulation of the whole facility.
What is included in P&I Diagrams
P&IDs contains all the details about physical components involved in material processing, i.e.:
- Process equipment with specifications (e.g. turbines, fans, vessels, pumps, etc.);
- Piping and line specifications, as well as process piping system components (e.g. fittings, flanges, valves, actuators, insulation, etc.);
- Instrumentation and control system components (e.g. indicators, gauges, alarms, interlocks, control input and output);
The function of P&IDs is also to specify parameters of those components as well as parameters of the processed material flowing along the pipelines and the operating procedures of the facility:
- Flow directions and process variables such as temperature, pressure or flow rate;
- Material specifications;
- Computer Control System input.
How to read P&ID drawings
P&IDs – unlike floor plans or maps – are not scaled drawings. They don’t visually represent the proximity of given components, their shape, or their physical coordinates in the facility. Their main purpose is to show the parameters and elements of the processing system, not its proportions or topography.
Elements drawn in P&IDs are represented by codes and graphic symbols. These may vary from company to company, so P&IDs come with Lead Sheets (or Legend Sheets) attached, where notation rules and symbols are explained. Usually, they follow industry standards, such as ANSI/ISA-5.1-2009 (Instrumentation Symbols and Identification).
Because going back and forth between the process drawing and the Lead Sheet is quite cumbersome, a more convenient approach might be displaying the processing facility in a digital model instead, where all the relevant information is easily accessible.
P&ID Codes And Symbols
Decoding P&ID Tagging Systems
Every engineering team establishes their own instrument and equipment tagging convention and explains it on the Lead Sheet. The instrument tags are written in callout bubbles next to the device or inline with the piping or electrical line.
There are some common tagging conventions. For example:
- “P” – First Letter stands for “Pressure”
- “D” – Second letter is a modifier for the first and stands for “Differential”
- “I” – Third letter stands for “Indicating”
- “T” – Fourth letter stands for “Transmitter”
- 1703 is the loop number (the Electrical Engineering eggheads need loop numbers too)
You can find a fuller identification and reference designation list on Wikipedia or in the ISA-5.1 standard guide.
P&ID symbols
Here are some of the P&ID symbols you are most likely to encounter in the processing industry:
1. Instruments – devices used for measurement and control of fluids and material streams. They measure, display, and control parameters such as flow, temperature, pressure, etc.
Instruments are identified on the P&ID diagram through their tagging code (according to a tagging convention included in the Lead Sheet), while the graphic symbol of the instrument represents how it can be accessed and operated, rather than what the device’s function is (for example, a pressure gauge can be represented by the same graphic symbol as level transmitter – they will be identified through their tags).
Example
Image: Instrumentation that contains a transmitter, a controller, and a control valve:
Source: ANSI/ISA-5.1-2009 – Instrumentation Symbols and Identification
2. Piping: lines connecting different parts of the process, where the media flows through. These are pipes, tubes, and hoses. Process lines on the drawing will also have a tag with parameters such as line number, piping size, class, insulation, etc.
3. Communication/Signal Lines – Lines representing process control systems, with different signal types to communicate information between components, instruments, and the control system computers.
4. Most Common Process Equipment
There are dozens of different equipment types that are used in process engineering, and each one of them can be drawn differently on P&IDs according to a given company’s guidelines. Below, you can see some of the examples of the most common ones.
Valves – the essential elements that regulate, direct, or control the flow of a fluid in the pipeline, by opening, closing, or partially obstructing the passageways.
Most common valve types
Other valve types
Vessels – containers where fluids are stored or processed through chemical reactions, mechanical manipulation, heating, cooling, stirring, and other methods.
Pumps – devices that move fluids (liquids or gases), or sometimes slurries, along the pipeline.
Other Equipment – there are dozens of other types of process equipment that would make their own book to be listed. Some typical examples are fans, turbines, motors, conveyors, compressors, drains, and many others.
On top of that – every company can add their proprietary equipment and this is why engineers use their own P&ID graphic libraries in the design software they use.
Examples of process equipment:
More P&ID Examples
The best way to start learning how to draw a P&ID is to study diagrams made by other engineers. The examples below can be a good reference for how these documents are laid out and annotated:
3) Via Automation Forum – P&ID diagram for Air supply system
How is P&ID used in process engineering?
P&ID is a more detailed elaboration of a Process Flow Diagram (PFD). PFD is the main drawing created by process engineers to show the relationships between a chemical process’ major equipment (pumps, vessels, turbines, heaters, etc.) and the flow and properties of chemical fluids used in the process (temperature, pressure, fluid density, flow rate, etc.) The process Flow Diagram doesn’t show minor components (e.g. pressure-flow instruments) nor details about piping systems in the facility.
P&IDs are used in design, development, operations, management and maintenance of chemical processing plants. They are used extensively by all engineering disciplines, like process, piping, mechanical, civil, electrical and instrumentation.
An example of a process flow diagram made for the electric circuit simulations
Process Design And Development
P&IDs are usually developed by process engineers based on the PFD to add details required for the facility design and construction project.
P&IDs are used in front-end engineering design (FEED) as well as engineering, procurement, and construction (EPC), where they serve as a basis to generate a “Bill of Materials.”
P&ID is the roadmap of any process plant engineering project. It is used to plan its staffing, timeline, and budget. Other engineers, project managers, and construction workers use it as a basis for their work, so small changes made to P&IDs during the construction stage might force other engineers or contractors to redo their work, causing delays and additional costs.
Piping engineers use P&IDs for material procurement and for designing pipe routing in the plant, electrical engineers use it to plan electrical circuits and architects – to design the facility building. Multiple, connected P&IDs are created for different parts of the process flow of a processing facility
Operations, Safety And Maintenance
P&IDs are used for operation, control, and shut-down procedures of a processing plant. They specify regulatory and plant safety requirements; they are used to developing facility operation guidelines (such as start-up and shut-down, monitoring procedures) and standards. P&ID is also a guide for operational data.
They are used in the training of facility operating staff, field engineers, and maintenance professionals. P&ID is the fundamental document for HAZOP, Model review, and Process Safety Management.
Over the plant’s lifetime, P&IDs are usually updated as the facility gets expanded, modernized, or modified to meet recommendations of Process Safety Management audits.
How A Custom-built P&ID Application Makes A Difference In Process Design And Management
Although there is a set of standards for P&ID drawings, every company that needs to make them has different needs, graphic styles, and workflows. This is where collaborating with software developers on a customized solution can end up saving costs further down the line.
Personalised interfaces for managers and non-engineers
Designing a process flow requires very specialized engineering experience, but since not everyone working for a processing company is a process engineer, they should have a customized yet simple-to-read interface that displays the information they need to know in order to accomplish the tasks. The interactive palette with custom objects is the feature that enriches the diagram drafting platform we developed for the customer.
For example, production managers’ work – be it procurement, facility management, safety and health regulations, etc. – will be much easier if they can get a dashboard that displays components that need to be purchased or will soon need replacement due to expiring warranty or abnormalities registered by sensors. Here, the visual libraries, such as GoJS come with help. The library enables simple drag&drop functionality that enables quick and easy operating on nodes, as well as positioning components at any place on the canvas. Instead of working with multiple drawings, applications, and plugins, our client uses a single platform that integrates into one interface their supplier libraries, equipment monitoring, and a financial system to help manage their budget. Not only can financial managers extract reports easily, but process designers will also know whether they’re staying within budget limits as they add and modify elements of the drawing.
Process flow diagram to illustrate the product configuration
Faster and mistake-proof design process
Customized process design platforms can make the job easier, more reliable, and streamlined for engineers.
With a custom symbol library accessible to all stakeholders of the process plant, the P&ID elements stay consistent and updated across different projects and subunits of the company. One of the most valuable application features, for increased readability and efficiency of design, is being able to add custom nodes and links and nesting complex subsystems within a wider context. You can benefit from various functionalities that GoJS visual library enables you to use. A whole process loop can be displayed as a simple element in the process overview, and the internal details can be expanded into a separate drawing with one click. Selected parts of any P&ID can be hidden or shown as needed.
A custom-built solution that we developed with a client from the oil&gas industry, also integrates best design practices and safety rules to validate the P&ID in real-time, as it is being developed by the engineer. The design tool highlights the parts that need to be remade and display HAZOP warnings with safety recommendations.
And lastly, the platform enables real-time collaboration and P&ID review process to assure that no mistake or opportunity for improvement goes unnoticed by the engineering team. While working with IoT sensors connected to the system, the user can gather and observe the actual condition of the whole set-up. The visual representation enables ad hoc reactions and delivering the most suitable solutions to the occurring issues.
Live Process Flow Simulation
For a client in the oil & gas industry, we developed an application that simulates events in the processing system, based on the Process Flow Diagram. The SCADA diagram below is a simple simulation of the flow along the pipes.
Flow diagram for simulation made with GoJS
This simulation can reflect the exact changes that occur in the process flow when a selected part of the P&ID is manipulated. Depending on the user’s needs, various alerts can be set up to notify of possible threats as certain elements are modified.
Using a diagram editor with a simulation feature creates a digital twin of the processing facility, which allows people involved in its operations to explore different scenarios, such as modernization plans or H&S (Health and Safety) scenarios.
While preparing and conducting simulations in P&ID, there are plenty of modern technical approaches merging visualization and engineering. JS visual libraries, such as GoJS, can be helpful as they work well for creating interactive diagrams used in simulations. In simple words, GoJS can be beneficial for simulations as it allows for reusable templates. The user benefits from previously created templates to superimpose data on them and observe changes in the simulation model. The GoJS makes the diagrams acting like a state machine that records, saves, and recreates the required state for further analysis. From the visual point of view, the GoJS enables choosing various data representations for one data model to change templating data. With virtualization functionality, the user can process bog data sets or map grid infrastructures.
Read more on how we created live simulation features for a client in the oil & gas sector:
Summary
P&IDs are as old as the process industry. While the rules and guidelines of the domain have been more or less consistent over the past decades, the digital transformation has revolutionized the way engineering is done, and switching to a custom-built P&ID platform can make a significant difference by boosting productivity, reducing the number of applications used and lowering the risk of costly and dangerous mistakes.
Creating custom P&ID software with a dedicated development team can give you more than just a diagram design tool. You can build one platform for all your design, management, and security needs, with real-time monitoring and design simulation of the processing facility.
P&IDs are no longer just technical drawings and the digital solutions built to create and manage them reflect that.