ASME Y14.40.8-2002 pdf free download.ADOPTION NOTICE.
ASME Y14.40.8 specifies graphical symbols For valves and dampers in diagrams, including symbols for general-purpose valves, those used in fluid power systems, and hygienic valves used in the food and pharmaceutical industries.
For the fundamental rules of creation and application of graphical symbols in diagrams, see ASME Y14.40.O.
For an overview of the ASME Y14.40 series, information on the creation and use of registration numbers for identifying graphical symbols used in diagrams, rules for the presentation and application of these symbols, and examples of their use and application, see ASME
Y14.40.1.
2 REFERENCES
The following references contain provisions that, through reference in this text, constitute provisions of this Standard. The latest edition applies.
ASME Y14.44J.O, Basic Rules for the Design of Graphical Symbols for Use in the Technical Documentation of Products
ASME Y14.40.1, Graphical Symbols for Diagrams, Part I: General Information and Indexes
ASME Y14.40.2, Graphical Symbols for Diagrams, Part 2: Symbols Having General Application
ASME Y14.40.4, Graphical Symbols for Diagrams, Part 4: Actuators and Related Devices
Publisher: The American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY
10016; Order Department: 22 Law Drive, lox 2300,
Fairfield, NJ 07007
3 TERMS AND DEFINITIONS
For the purposes of this Standard, the following terms and definitions apply.
safety ivc: valve that automatically, without the assistance of any energy other than that of the fluid concerned, discharges a certified quantity of the fluid so as to prevent a predetermined safe pressure being exceeded, and that is designed to reclose and prevent the further flow
of fluid after normal pressure conditions of service have been restored.
3.2
‘acuutn rlr: valve that automatically and without the assistance of any energy other than that of the gas concerned, admits gas to a pipeline or tank in order to prevent a predetermined safe underpressurc being exceeded.
3.3
control vah’e: power-operated valve in an industrial. process control system for changing the flow rate of the process fluid.
3.4
restrictor: device that restricts the flow of a fluid, thereby creating a pressure drop.
rest rictor vak: valve in which the inlet and outlet ports are interconnected through a restricted passageway.
NOTE: In fixed nstridor valve, the crosssectionaI .irea cannot be .llteftd; in an ad1ustahlc rcitridor valve, the ci .ectionaI area can be adustcd.
3.6
release vahe: valve through which undesired air or steam in a pipe system may be released.
3.7
valve in which, with varying inlet pressure or outlet flow, the outlet pressure remains substantially constant, but in which the inlet pressure remains higher than the selected outlet pressure.
ptre-reliefvaIve: valve that limits maximum pressure by exhausting fluid when the required pressure is reached.
3.9
exhaust valve: valve in which the outlet is automatically opened to exhaust when the air pressure falls at the inlet.