Piping and instrumentation diagram

R & I - Flow diagram indicates a pipe and instrument flow diagram in the plant and process technology (including R I flow chart, R & I diagram, P & ID diagram, English Piping and Instrumentation Diagram or P & ID).

7.1 Differences to the European Standard
7.2 Plate assembly according to ISA 5.1

The contents and purpose

Based on the basic flow scheme, the R & I flow diagram is created. In R & I - flowsheet are all components required for the operation of a plant, such as containers, apparatus, pumps, compressors, heat exchangers, piping, valves and gauges, shown symbolically.

All lines which represent a pipeline are marked with nominal size, nominal pressure, medium, pipe class and an identification number.

Similarly, it is for the determination of measurement and control technology. In standardized symbols ( ovals) is defined, where and what is to be measured or controlled. These receive an identification number for further processing. Control loops are represented with action lines ( from the location of the measurement to the actuator ).

The scheme includes the following information:

Kind and description of the equipment and / or machinery
Pipes, valves with nominal diameters, pressure classes, materials
Drives
Tasks of the facilities for measuring and control

Additional information can be specified, such as high altitudes of the equipment, more equipment, more names ( eg valves ).

After approval of the R & I - flowsheets by the customer ( and possibly also by public authorities) the detailed planning ( detailed engineering ) begins.

R & I - flow diagram according to ISO standard

In Germany are represented 10628 R & I flow charts according to DIN EN ISO. More piping symbols can be found in DIN 2429. Lines of action of and control organs are presented in accordance with EN 62424 or ISO 3511.

Letters and labeling

For the marking of measuring and control stations with the standards EN 62424/ISO 3511 or ISA S5.1 are applied.

The comprehensive identification of all equipment, piping and instruments in industrial systems is in EN 61346 ( Industrial systems, installations and equipment and industrial products - Structuring principles and reference designations ) described or in the national standard DIN 6779 (coding for technical products and technical product documentation ). There, all measurement and control points of the main group B are assigned. For the subgroups, the code letters according to ISO 14617-6 are used.

In the field of power plant construction, the components ( vessels and piping, and instruments) in the power plant Plate System (PPS ) or under the new system for the identification (coding) of power plant components (RDS -PP) are indicated.

Measuring and Control Stations

The measuring and control stations are represented in accordance with ISO 3511. By ISO 3511, there is no German translation. The formerly valid DIN 19227-1 was replaced by the European Standard EN 62424 in January 2010.

Description of ANSI code

Measuring points were labeled according to DIN 19227-1 with a shortcut, which consists of one or more letters and a marking ( usually a sequence of digits ). The letters provide information about the function and role of the measuring point and consists of a Erstbuchstaben and possibly one or more supplementary letter and subsequent letters.

EN 62424 is used instead of " First letter " the term " PCE- category", supplementary and follow-up letters ( which already share no overlap ) go into the so-called " PCE- processing function" on (PCE = Process Control Engineering ). Although the current standard assumes the bulk of the letter meanings, but also adds new and defines some of the existing order.

We can not and will not define all the details with this designation system. Together with the identification number is given to the instrument data sheet a reference. There you can range, height limits, details the installation and read much more accurate.

Succeeding letter - PCE - processing function

A alert message ( Alarming )
B restriction, limitation
C regulation / control ( controlling)
D difference ( Difference)
F ratio ( Fraction )
H upper limit on open
I analog display ( Indicating )
L lower limit of closed
O point of view character, yes / no display ( no error message )
Q integral, sum
R Storage / Recording ( Recording)
S Binary control function or switching function ( non-security ) ( Switching)
T transmitters for analog value processing (monitoring)
Y arithmetic function
Z Binary control function or switching function ( safety issue) ( Emergency)

Notes:

The letters I and R refer to the result of the previous processing function.
The PCE- processing functions A, H, L, O, S, and Z may only be used right out of the oval.
If subsequent letters are combined, should be taken in the order in the table below in series 1 and 2 from left to right and in series 1 and 2 from top to bottom: Row 1: FDYC Series 2: BQX

Examples

PI -512: Pressure Indicator
PDI -512: Differential pressure indicator
PICAH -512: Pressure control with display with alarm when exceeding an upper limit
F-100: current flow
FQ -100: total amount that has flowed through
TIRCSHAHL -618: temperature control with display, storage, switching on reaching the upper limit of normal and alarm on reaching the upper and lower limit

Programs for R & I - Flow diagram creation

(: Computer-aided design CAE German ) increasingly used programs in the field of computer- aided engineering for creating P & IDs scheme in plant engineering. The applications provide the flow chart symbols in a standardized size and thickness available and assist in their placement. In the labeling lists are provided and it is ensured that the correct license plate format is adhered to ( especially important in PPS). The data is usually stored in central databases. Thus, a subsequent evaluation of the data is possible.

Overview -to-use standards

Status: February 2010

EN ISO 7200 ( formerly DIN 6771-1 ) documents text field
EN ISO 10628 ( formerly DIN 28004 ) Flow diagrams for process plants - General rules
EN 60617 ( formerly DIN 40900 ) Graphical symbols for diagrams
EN 62424 ( formerly DIN 19227-1 ) representation of tasks of control systems - flow diagrams and data exchange between computer tools for flow imaging and CAE systems
ISO / TS 16952-1 ( formerly DIN 6779 ) Technical product documentation - Reference designation system - Part 1: General application rules
ISO 3511 Measuring, controlling, rules in process engineering
DIN 2429-1 Graphical symbols for technical drawings; Pipelines; General
DIN 2429-2 Graphical symbols for technical drawings; Pipelines; Functional representation
DIN 2481 Thermal power plants; Graphical symbols
DIN 19227-2 control; Graphical symbols and identifying letters for process control engineering; Showing details

R & I - flow scheme according to American Standard

Differences to the European Standard

In the United States R & I flow scheme based on the Anglo-American system of measurement. Symbols are displayed according to the American standard ISA.

This standard has no such strict classification scheme such as EN ISO 10628th symbols for apparatus and equipment are represented rather by their actual appearance. This leads, among other things, that the symbols for centrifugal pump and centrifugal blower is very similar. Passage fittings are presented similarly explicit as in the ISO standard after its operating principle, at Eckarmaturen and multiway valves, however, on the precise specification omitted ( no symbols for angle valve, angle valve ).

Instruments are not presented together, but explicitly split according to the individual functions.

Example of a flow measurement with display, control and recording:

ISO: FIRC
ISA: FT -FI -FR- FC

In technical drawings of international projects, it often comes to mixed markings.

Plate assembly according to ISA 5.1

First Letter

A analysis
P pressure (pressure )
T- temperature
Z position

Second letter

T transmission (transmitter )
R recording ( recorder )
I display ( indicator )

Example

Flow - transfer of control loop 1000A

Function identifier

First Letter F
Second letter T

Closed-loop identification

Loop number 1000
Suffix A

FT 1000A

Other examples

PT 1000A 1000A pressure transmission
PI 1000A Pressure Gauge
PIC 1000A pressure controller with display PID control loop
PIRC 1000A pressure regulator with recording and display

Computer-aided engineering

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