《BS 1646-1-1979 ISO 3511-I-1977.pdf》由会员分享，可在线阅读，更多相关《BS 1646-1-1979 ISO 3511-I-1977.pdf（20页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS 1646-1: 1979 ISO 3511/I-1977 Symbolic representation for process measurement control functions and instrumentation Part 1: Basic requirements ISO title: Process measurement control functions and instrumentation Symbolic representation UDC 53.08:621.2:003.62 Licensed Copy: sheffie
2、ldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1646-1:1979 This British Standard, having been prepared under the direction of the Industrial Process Measurement and Control Standards Committee, was published under the authority of the Executive Board and come
3、s into effect on 30 November 1979 BSI 12-1998 First published December 1950 First revision March 1964 Second revision 30 November 1979. The following BSI references relate to the work on this standard: Committee reference PCL/4 Draft for comment 78/28752 DC ISBN 0 580 10980 1 Cooperating organizatio
4、ns The Industrial Process Measurement and Control Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: British Gas Corporation British industrial Measuring and
5、Control Apparatus Manufacturers Association* British Steel Corporation CBMPE* Control and Automation Manufacturers Association (BEAMA) Department of industry (Computers Systems and Electronics) Electrical, Electronic, Telecommunications and Plumbing Union Electricity Supply Industry in England and W
6、ales Electronic Engineering Association Engineering Equipment Users Association* Institute of Measurement and Control* Institution of Electrical Engineers* Institution of Gas Engineers* Oil Companies Materials Association* Post Office Engineering Union Scientific Instrument Manufacturers Association
7、* Sira Institute The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of Consulting Engineers Chemical industries Association Ministry of Defence The T
8、ransmission and Distribution Association (BEAMA) Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1646-1:1979 BSI 12-1998 i Contents Page Cooperating organizations Inside fr
9、ont cover National foreword ii 0 Introduction 1 1 Scope and field of application 1 2 Definitions 1 3 Size and outline of basic symbols 2 4 Letter code 4 5 Types of line and assembly of symbols 4 6 Examples of use of the symbols 7 Table Letter code for identification of instrument functions 5 Publica
10、tions referred to Inside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1646-1:1979 ii BSI 12-1998 National foreword This British Standard has been prepared under the direction of the Industrial Process Measurement and Control
11、 Standards Committee. It was first published in 1950 and subsequently revised in 1964. This revision is identical with ISO 3511/I-1977 “Process measurement control functions and instrumentation Symbolic representation Part I: Basic requirements” published by the International Organization for Standa
12、rdization (ISO). Terminology and conventions. The text of the international standard has been approved as suitable for publication, without deviation, as a British Standard. Some terminology and certain conventions are not identical with those used in British Standards; attention is especially drawn
13、 to the following: Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applic
14、ation. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International standardCorresponding British Standard IEC 117BS 3939 Graphical symbols for electrical power, telecommunications and electronics diagrams (Technically equivalent) ISO/R
15、 128-1959BS 308 Engineering drawing practice Part 1:1972 General principles (Technically equivalent) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 14, an inside back cover and a back cover. This standard has been updated (see copyright date
16、) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1646-1:1979 BSI 12-19981 0 Introduction This International Standard has b
17、een devised to provide a universal means of communication between the various interests involved in the design, manufacture, installation and operation of measurement and control equipment used in the process industries. Requirements within the industries vary considerably, and in recognition of thi
18、s, this International Standard is presented in three parts as follows: Part I: Basic requirements (directed towards the needs of those whose prime interest is in basic measurement and control means); Part II: Extension of basic requirements; Part III: Detailed symbols. The three parts together are i
19、ntended a) to meet the requirements of those who, possibly employing more sophisticated measurement and control means, may wish to depict such aspects as the measurement techniques embodied in a particular instrument, or the means hydraulic, pneumatic, electrical, mechanical used for its actuation;
20、b) to provide standard symbolic representation for process measurement control functions and instrumentation. These symbols are not intended to replace graphic symbols for electrical equipment as contained in IEC Publication 117. 1 Scope and field of application Part 1 of this International Standard
21、 establishes a symbols system for use in depicting the basic functions of measurement and control equipment in relation to the plant with which it is associated. The system has been intentionally limited to the identification of instrument functions and does not provide means of illustrating specifi
22、c instruments. 2 Definitions The following definitions are used solely for the purpose of this International Standard to assist in the application and understanding of the symbol system. 2.1 point of measurement the point in a process at which a measurement is or may be made 2.2 instrument a device
23、or combination of devices used directly or indirectly to measure, display and/or control a variable. This term does not apply to internal components of the instruments, for example resistor or receiver bellows 2.3 panel-mounted instrument an instrument that is mounted in a group normally accessible
24、to the operator 2.4 locally mounted instrument an instrument that is not panel mounted 2.5 correcting unit the unit comprising those elements (actuating and correcting) which adjust the correcting conditions, in response to a signal from the controller 2.6 actuating element that part of the correcti
25、ng unit which adjusts the correcting element, for example a response to a signal from the controller Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1646-1:1979 2 BSI 12-1998 2.7 correcting element that part of the correcting unit which d
26、irectly adjusts the value of the correcting conditions 2.8 alarm a device which is intended to attract attention to a defined abnormal condition by means of a discrete audible and/or visible signal, but which does not itself institute corrective action 2.9 set value the value of the controlled condi
27、tion to which the controller is set 3 Size and outline of basic symbols The symbol requirements given below have been adopted to provide for legibility and ease of drawing. If diagrams are to be photographically reduced, then these sizes should be correspondingly larger. 3.1 Point of measurement The
28、 symbol is a thin line connected to a flow line or to a plant equipment outline. If not connected to an instrument symbol, an identifying letter shall be placed close to this to designate the measurable property. The letters used shall comply with the table. The location of the symbol shall be funct
29、ionally correct and placed in the correct process sequence but need not illustrate the geographical position. However, where it is desirable, for clarification, to identify the location of the point of measurement within a plant equipment outline, a small circle of approximately 2 mm diameter may be
30、 used at this point at the end of the thin line as shown in the figures in 6.1.7 and 6.9. 3.2 Instrument The symbol comprises: a thin line circle of approximately 10 mm diameter; a letter code showing the property measured and function (see clause 4). A number may be included to facilitate identific
31、ation. Where the letter code/identification number cannot be accommodated within the circle, the circle may be broken. 3.3 Panel-mounted instrument The symbol is a thin line circle of approximately 10 mm diameter with a horizontal thin line across it. The line may be located at any height within the
32、 circle. NOTEFor an instrument mounted inside a control panel, the above symbol may include a second horizontal line. 3.4 Correcting element The symbol for a correcting element of unspecified type is an equilateral triangle with sides of approximately 5 mm length. When the type of correcting element
33、 is known, established symbols depicting particular correcting elements may be used, for example for a valve: Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1646-1:1979 BSI 12-19983 3.5 Actuating element 3.5.1 Automatic actuating element
34、 The basic symbol is a thin line circle of approximately 5 mm diameter, with a thin line to connect it to the correcting element symbol. 3.5.2 Automatic actuating element with integral manual actuating element The letter H shall be inserted in the circle if there is a manual as well as an automatic
35、facility for positioning the correcting unit. 3.5.3 Manual actuating element Where there is only a manual facility for positioning the correcting unit, the symbol consists of a semi-circle of approximately 5 mm diameter beneath a letter H, with a thin line to connect it to the corrrecting element. 3
36、.6 Correcting unit The symbol is the combination of the symbols for the actuator and the correcting element, for example: 3.7 Actuating element operation Response of the actuator to failure of the actuating energy may be indicated by an additional symbol, illustrated here for the particular example
37、of a control valve. Control valve opens on failure of actuating energy: Control valve closes on failure of actuating energy: Control valve retains position on failure of actuating energy: Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 16
38、46-1:1979 4 BSI 12-1998 A combination of the above symbols could be used to indicate the safe and permitted direction of drift: 4 Letter Code 4.1 Identifying letters The purpose of the instrument shall be defined by a letter code contained within the instrument symbol circle; this letter code shall
39、be constructed on the following basis: 4.1.1 The first letter shall denote the measured or initiating variable, and shall be in accordance with column 2 of the table, but should be modified, if necessary, by the addition of a letter in accordance with column 3. 4.1.2 Succeeding letters shall be in a
40、ccordance with column 4 of the table. 4.1.3 Where there are two or more succeeding letters, they shall be placed one after the other, in the sequence I R C T Q S Z A. (This does not apply to the letters corresponding to the modifiers in column 3 of the table.) The letter I may be omitted in the case
41、 of a self-indicating recorder. 4.1.4 For the use of the letter H to denote HAND (manual) operation, see 3.5. 4.2 Qualifying letters Where it is required to denote HIGH or LOW, the qualifying letters H or L may be used in association with the instrument symbol (see 6.1.5 and 6.1.8). 5 Types of line
42、and assembly of symbols 5.1 Types of line (see also ISO/R 128, Engineering drawing Principles of presentation1).) The types of lines used in the symbol system shall be as follows, it being conventional for a continuous thick line to represent the flow line of a process or the outline of a plant vess
43、el, etc. 5.1.1 The symbol for an instrument connection to a process is a continuous thin line, thinner than the lines used to delineate the plant. 5.1.2 The preferred general symbol for an instrument signal line is a continuous thin line, having a stroke repeated along its length. These strokes are
44、inclined at approximately 60 to the line. Alternatively, a continuous thin line without strokes may be used where there is no risk of confusion. Instrument signal lines shall be drawn thinner than process lines. NOTENo attempt is made in this part of this International Standard to distinguish betwee
45、n types of instrument actuation (for example electrical, pneumatic and hydraulic), such a distinction being unnecessary for an understanding of the function of the instrumentation. 1) At present under revision. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 03:10:56 GMT+00:00 2006, Uncontrol
46、led Copy, (c) BSI BS 1646-1:1979 BSI 12-19985 Table Letter code for identification of instrument functions 1234 First letteraSucceeding lettera Measured or initiating variableModifierDisplay or output function AAlarm B CControlling DDensityDifference EAll electrical variablesb FFlow rateRatio GGaugi
47、ng, position or length HHand (manually initiated) operated IIndicating JScan KTime or time programme LLevel MMoisture or humidity NUsers choicec OUsers choicec PPressure or vacuum QQualityb For example Analysis, Concentration, Conductivity Integrate or totalizeIntegrating or summating RNuclear radia
48、tionRecording SSpeed of frequencySwitching TTemperatureTransmitting UMultivariabled VViscosity WWeight or force XUnclassified variablesc YUsers choicec ZEmergency or safety acting a Upper case letters shall be used for the measured or initiating variable and succeeding letters for display or output
49、function. Upper case letters are preferred for modifiers, but lower case letters may be used if this facilitates understanding. b A note shall be added to specify the property measured. c Where a user has a requirement for measured or initiating variables to which letters have not been allocated and which are required for repetitive use on a particular contract, the letters allocated to Users Choice may be used provided that they are identified or defined for a particular measured or initiating variable and reserved for