1、BRITISH STANDARD BS 1646-3: 1984 Symbolic representation for process measurement control functions and instrumentation Part 3: Specification for detailed symbols for instrument interconnection diagrams UDC 53.08:681.2:003.62BS 1646-3:1984 This British Standard, having been prepared under the directi
2、onof the Industrial-process Measurement and Control Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 31 January 1984 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference PCL/4 Draft for comment 79/23678 DC
3、ISBN 0 580 13598 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Industrial-process Measurement and Control Standards Committee (PCL/-) to Technical Committee PCL/4 upon which the following bodies were represented: Association of Consu
4、lting Engineers Beama Transmission and Distribution Association British Industrial Measuring and Control Apparatus Manufacturers Association (BEAMA) Energy Industries Council Institute of Measurement and Control Institution of Gas Engineers Ministry of Defence Amendments issued since publication Amd
5、. No. Date of issue CommentsBS1646-3:1984 BSI 07-1999 i Contents Page Committees responsible Inside front cover Foreword ii 0 Introduction 1 1 Scope and field of application 1 2 Definitions 1 3 Symbols 3 Annex Examples of the use of graphical symbols 17 Publications referred to Inside back coverBS16
6、46-3:1984 ii BSI 07-1999 Foreword This British Standard has been prepared under the direction of the Industrial-process Measurement and Control Standards Committee and is technically equivalent to the international Organization for Standardization (ISO) draft international standard ISO/DIS3511/3 “Pr
7、ocess measurement control functions and instrumentation Symbolic representation Part 3: Detailed symbols for instrument interconnection diagrams”. The decision to publish now rather than await the publication of the corresponding ISO standard, recognises the urgent need of the industry for a standar
8、d with world-wide application based on an international text. It is anticipated that any differences with the finally published ISO version will be of a minor nature. The standard incorporates minor editorial and drawing changes which have been submitted to the ISO technical committee in order to co
9、rrect errors in the draft international standard. For ease of production the text of the draft international standard has been used for this British Standard; some terminology and certain conventions are not identical with those used in British Standards. The Technical Committee has reviewed the pro
10、visions of IEC 113-5, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. The logic elements in accordance with IEC117-15, referred to in3.13, are identical with those given in BS3939-21. A British Standard does not purport to i
11、nclude all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International standard Corresponding British Standard IEC 117 a
12、BS 3939 Graphic symbols for electrical power, telecommunications and electronics diagrams (Technically equivalent) a Undated in the text Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 20, an inside back cover and a back cover. This standard h
13、as been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS1646-3:1984 BSI 07-1999 1 0 Introduction This British Standard has been devised to provide a universal means of communication among the various int
14、erests involved in the design, manufacture, installation and operation of measurement and control equipment used in the process industries. Requirements within the industries vary considerably; in recognition of this, this British Standard is presented in three parts as follows: Part 1: Basic requir
15、ements (directed towards the needs of those employing comparatively simple measurements and control means); Part 2: Extension of basic requirements; Part 3: Detailed symbols for instrument interconnection diagrams. The three parts together are intended to: a) meet the requirements of those who, poss
16、ibly 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; b) provide standard symbolic representation for proces
17、s 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 This part of BS1646 specifies instrument symbols for use on interconnection diagrams used for
18、the design, installation, and maintenance of process measurement and control systems. These detailed symbols are not normally intended for drawings that use the functional symbols given in BS1646-1 and BS1646-2. However, the symbols specified in this part of BS 1646 show, by detailing the components
19、, the external connections between units of equipment. Information on the internal connections in units is not normally included, but references to the appropriate circuit or wiring diagrams may be provided. When an instrument is composed of more than one functional part, the different symbols may b
20、e combined, for example, recorder controller. The dimensions of the symbols are unspecified, provided the ratio of the side lengths is maintained according to this part of BS1646 1) . If not otherwise stated, contact symbols should be shown open. The diagrams may employ single line or multi-line rep
21、resentation and may be combined with, or replaced by tables, providing clarity is maintained. For further assistance see IEC113-5, Preparation of interconnection diagrams and tables. 2 Definitions The following defintions are used solely for the purposes of this part of BS1646, to assist in the appl
22、ication 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 or combination of devices used directly or indirectly to measure, display and/or control a variable. This term does not apply to internal c
23、omponents of the instruments, for example resistor or receiver bellows 1) This rule has been adopted provisionally until such time as technical committee ISO/TC 10 prepares an International Standard for the representation of graphical symbols used on technical drawings.BS1646-3:1984 2 BSI 07-1999 2.
24、3 panel-mounted instrument an instrument that is mounted in a group normally accessible 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
25、response to a signal from the controller 2.6 actuating element that part of the correcting unit which adjusts the correcting element, for example a response to a signal from the controller 2.7 correcting element that part of the correcting unit which directly adjusts the value of the correcting cond
26、itions 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 condition to which the controller is set 2.10 interco
27、nnection diagram diagram representing the connections between the different units of an installationBS1646-3:1984 BSI 07-1999 3 3 Symbols Number Description Use of equipment or explanation of symbol Symbol 3.1 Instruments 3.1.1 Non-converting instruments Examples: indicators, recorders, counters 3.1
28、.1.1 Basic symbol Preferred ratio of sides 1 : 2 3.1.1.1.1 Basic symbol with connections Terminals may be placed on any basic symbol 3.1.1.2 Indicator Arrow points upwards to left 3.1.1.2.1 Analogue indicator 3.1.1.2.2 Digital Indicator 3.1.1.3 Recorder State number of records if more than one 3.1.1
29、.3.1 Analogue recorder 3.1.1.3.2 Digital recorder 3.1.1.4 Counter 3.1.1.5 Measuring point selection switch (electrical) State number of measuring points (for example, 12 points) 3.1.1.6 Measuring point selection valve (gas or liquid) State number of measuring points (for example, 3 points)BS1646-3:1
30、984 4 BSI 07-1999 Number Description Use of equipment or explanation of symbol Symbol 3.1.1.7 Switch for alarm signal or initiator Position Input Left Right = minimum = maximum If symbol is turned 90 , Lower Upper = minimum = maximum 3.1.1.8 Manual control station 3.1.1.9 Manual control station with
31、 hand/auto or remote/local switch 3.1.2 Converting instruments Examples: transmitters, controllers, relays 3.1.2.1 Basic symbol Preferred ratio of sides 1 : 1 3.1.2.1.1 Basic symbol with connections Terminals may be placed on any basic symbol 3.1.2.2 Controller, closed-loop The apex of the inscribed
32、 V is on the output-signal side. The apex angle shall be 90 . 3.1.2.3 Controller with increasing input signal giving increasing output signal When symbol is turned, the arrow indicating the direction of output action shall remain in the vertical up position 3.1.2.4 Controller with increasing input s
33、ignal giving decreasing output signal When symbol is turned, the arrow indicating the direction of output action shall remain in the vertical down position. 3.1.2.5 Ratio controller 3.1.2.6 Converter, transmitter, transducer, etc. State type and range of input and output signals 3.1.2.7 Computing re
34、lay State computing function: For example, square root extractorBS1646-3:1984 BSI 07-1999 5 Number Description Use of equipment or explanation ofsymbol Symbol 3.1.2.8 Amplifier 3.1.2.9 Signal memory 3.1.2.9.1 Analogue signal memory 3.1.2.9.2 Digital signal memory 3.1.3 Logic elements According to IE
35、CPublication117, Part15 3.1.4 Examples of instruments 3.1.4.1 Indicating controller with switch for minimum signal 3.1.4.2 Recorder and counter with switches for minimum and maximum signal 3.1.4.3 Recording controller 3.1.4.4 Indicating controller with recorder for second measured variableBS1646-3:1
36、984 6 BSI 07-1999 Number Description Use of equipment or explanation ofsymbol Symbol 3.1.4.5 Recording ratio controller with switches for minimum and maximum signal 3.1.4.6 Transmitter: input, 0 to 250 kPa differential pressure; output, 20 to 100 kPa standard signal 3.1.4.7 Signal converter with out
37、put indicator: input, 20 to 100 kPa; output, 4 to 20 mA 3.1.4.8 Signal converter: input, 20 to 100 kPa; output, 20 to 4 mA 3.1.4.9 Indicator with selector switch for 6 measuring points 3.1.4.10 Digital indicator with switch for maximum signal 3.1.4.11 Oxygen transmitter: input 0 to 10 % O 2 ; output
38、 0 to 50 mA 3.1.4.12 Rate-of-change relay with high-rate switch 3.2 Correcting units 3.2.1 Correcting elements 3.2.1.1 Valve If type of valve is to be shown, the relevant ISO symbol shall be used 3.2.2 Actuating element A vertical line shall be connected to the correcting element symbolBS1646-3:1984
39、 BSI 07-1999 7 Number Description Use of equipment or explanation ofsymbol Symbol 3.2.2.1 Manual actuator 3.2.2.2 Diaphragm actuator 3.2.2.3 Solenoid actuator Preferred side relationship 1 : 2 3.2.2.4 Piston actuator Preferred side relationship 1 : 2 3.2.2.5 Rotary motor actuator 3.2.2.6 Spring actu
40、ator 3.2.2.7 Float actuator 3.2.2.8 Weight actuator 3.2.2.9 Centrifugal force actuator 3.2.3 Accessories 3.2.3.1 Lock-up to block movement to the left The separate vertical line should connect to the symbol for an actuator such as a solenoid 3.2.3.2 Lock-up initially permitting movement to left and
41、right, but which blocks return to left after movement to right The separate vertical line should connect to the symbol for an actuator such as a solenoid 3.2.3.3 Limit switch “Make” contact, closed when actuated 3.2.3.4 Limit switch “Break” contact, open when actuatedBS1646-3:1984 8 BSI 07-1999 Numb
42、er Description Use of equipment or explanation ofsymbol Symbol 3.2.3.5 Correcting element takes fail-safe position when actuation energy fails Opens on failure Closes on failure Retains position on failure 3.2.4 Examples of correcting-unit assemblies. When confusion may occur between mechanical and
43、electrical connections, a double line may be used for mechanical connections. Switches shall be shown in non-actuated position. Orientation of switch symbol is optional. 3.2.4.1 Correcting units with integrally mounted switches 3.2.4.1.1 Control valve with diaphragm actuator with integrally mounted
44、switch actuated in valve-closed (0 %) position. Contact closes when switch is actuated. 3.2.4.1.2 Control valve with piston actuator with integrally mounted switches actuated in valve-closed (0 %) position and valve-opened (100 %) position. Contacts close when switches are actuated. 3.2.4.1.3 Contro
45、l valve operated by rotary motor with integrally mounted switch with two contacts, one actuated in valve-closed (0 %) and the other in valve-opened (100 %) position, and with torque switch. Contacts close when switches are actuatedBS1646-3:1984 BSI 07-1999 9 Number Description Use of equipment or ex
46、planation of symbol Symbol 3.2.4.2 Control valve with diaphragm actuator, positioner, and with manual operation 3.2.4.3 Control valve, spring-actuated to open, hand-actuated to close. Normal operating position for valve is in closed position and latched. Latch is released by a solenoid when solenoid
47、 is actuated. 3.3 Detectors and connections for detectors 3.3.1 Basic symbol for detectors Ratio of sides 1 : 2. If necessary, the letter of the measuring function may be inserted in the symbol for detector (see BS 1646-1) 3.3.1.1 Basic symbol for nozzle or boss on line or vessel Ratio of sides 1 :
48、1 3.3.1.2 Protecting well for detectors 3.3.1.3 Nozzle or boss with well for detector 3.3.1.4 Insertion pipe 3.3.1.5 Nozzle or boss with insertion pipe 3.3.2 Detectors for flow and volumetric flow If necessary, the letter of the measuring function may be inserted in the symbol for detector (see BS 1
49、646-1) 3.3.2.1 Flow (general) 3.3.2.2 Volumetric flow-meter (general) This symbol must be used in conjunction with mechanical integrator, transmitter, or other functional elementBS1646-3:1984 10 BSI 07-1999 Number Description Use of equipment or explanation of symbol Symbol 3.3.2.3 Venturi tube 3.3.2.4 Flow nozzle 3.3.2.5 Orifice plate 3.3.2.6 Variable-area meter 3.3.2.7 Turbine meter 3.3.2.8 Positive displacement meter 3.3.2.9 Electromagnetic flowmeter 3.3.3 Detectors for temperature If necessary, the letter of the measuring function may be inserted
