# ANSI/IEEE Gas flow switch form Canonical URL: https://eloragrid.ai/symbols/ansi-gas-flow-switch Publisher: Elora Grid Updated: 2026-10-28 Lookup label: FS GAS Drawing use: Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: Flow Switch Normally Open - Gas Autodesk IEEE Symbol Preview: Miscellaneous Switches, block HFS11S20. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [Gas flow switch](https://eloragrid.ai/symbols/gas-flow-switch) IEEE-library form of gas flow switch: a gas-flow switch changes contact state for a specified gas-flow condition. ## In plain English ### What does ANSI/IEEE Gas flow switch form mean? This reference locates gas flow switch in Autodesk's IEEE-oriented miscellaneous switches family. A gas-flow switch changes contact state for a specified gas-flow condition. Its process connection and operating requirement belong in the equipment schedule as well as the control logic. The public library uses HFS11S20 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. ### A simple example Read the operating mechanism and the contact reference state together. Cross-reference every associated contact to the same device and show which movement, signal or reset changes its condition; the symbol alone does not establish the complete switching sequence. ### What the drawings help you do Do not substitute liquid-flow characteristics for the selected gas device. Gas-flow operation is a process-specific input and is separate from the contact's electrical rating. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted. ### This particular reference IEEE-library form of gas flow switch: a gas-flow switch changes contact state for a specified gas-flow condition. Gas-flow operation is a process-specific input and is separate from the contact's electrical rating. ### Terms - Normally open / normally closed: The contact state in the normal condition defined for the drawing. - Terminal: An identified point where a conductor connects. - Signal: Electrical information passed between devices, rather than necessarily the main power supply. Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram. - [Autodesk IEEE Symbol Preview — Miscellaneous Switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-278F6C21-B1A6-4EA1-A535-E78D53BBD10D.htm) ## What it represents This reference locates gas flow switch in Autodesk's IEEE-oriented miscellaneous switches family. A gas-flow switch changes contact state for a specified gas-flow condition. Its process connection and operating requirement belong in the equipment schedule as well as the control logic. The public library uses HFS11S20 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. Read the operating mechanism and the contact reference state together. Cross-reference every associated contact to the same device and show which movement, signal or reset changes its condition; the symbol alone does not establish the complete switching sequence. Do not substitute liquid-flow characteristics for the selected gas device. Gas-flow actuation is a process-specific input and is separate from the contact's electrical rating. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted. ## How to read it - Do not substitute liquid-flow characteristics for the selected gas device. - The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation. ## Information to show or reference - Identify gas service - Record operating condition - Reference contact and reset action ## Important distinction Gas-flow actuation is a process-specific input and is separate from the contact's electrical rating. ## Facts - Convention evidence: Autodesk IEEE Symbol Preview: Miscellaneous Switches; published form: Flow Switch Normally Open - Gas. - Public vendor block: HFS11S20. Vendor library token, not an IEEE symbol number. - Drawing role: Actuated indication - Identifier status: The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name. - Artwork scope: Original educational geometry. Exact standard graphics, product ratings and terminal pinouts are not certified. ## Public references - [Autodesk IEEE Symbol Preview — Miscellaneous Switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-278F6C21-B1A6-4EA1-A535-E78D53BBD10D.htm) — Autodesk. Public IEEE-oriented Miscellaneous Switches table explicitly lists HFS11S20 as Flow Switch Normally Open - Gas. This supports the vendor convention context, not reproduction of the publisher graphic. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.