ASTM F1793-97 (2021) PDF

Full title and description

ASTM F1793-97(2021) — Standard Specification for Automatic Shut-Off Valves (also known as Excess Flow Valves, EFV) for air or nitrogen service. The specification covers self-contained automatic shut‑off valves intended to act as safety devices that quickly and automatically shut off flow under excess‑flow conditions caused by a downstream failure or casualty (for example, a hose rupture).

Abstract

This specification defines types, styles, sizes, pressure ratings, and end connections for automatic shut‑off (excess flow) valves used in air or nitrogen service and prescribes required examinations and performance tests (visual examination, hydrostatic shell test, seal tightness test, external leakage test, and set‑point test). It clarifies unit conventions (inch‑pound primary; SI provided for information) and includes requirements for set‑point behavior and seating leakage.

General information

• Status: Active / Reconfirmed (reapproval rounds recorded through 2021).
• Publication date: Original designation 1997; most recent reapproval/last updated entry shown January 21, 2021.
• Publisher: ASTM International.
• ICS / categories: 23.060.01 (Valves — general).
• Edition / version: F1793-97 with reapproval references shown as F1793-97(2021) / R21 (reconfirmed).
• Number of pages: 7 pages (short specification).

Scope

This specification applies to self‑contained automatic shut‑off valves (excess flow valves) for air or nitrogen service intended as safety devices to interrupt flow automatically under excess‑flow conditions caused by downstream failure or casualty (e.g., hose rupture). It covers required valve types (Types I and II), styles (Styles 1 and 2), sizes, pressure ratings and allowable end connections, and establishes test and performance criteria. Inch‑pound units are the standard; SI equivalents are informational only.

Key topics and requirements

• Valve types and styles: designation of Types I and II and Styles 1 and 2 with specified sizes and end connections.
• Performance and acceptance tests: visual examination, hydrostatic shell test, seal‑tightness test, external leakage test, and set‑point test.
• Set‑point and accuracy requirements: set‑point accuracy and adjustment ranges (set‑point accuracy tolerances and adjustment ranges are specified in the standard).
• Leakage and seating: defined limits for flow leakage after shut and requirements for external leakage to be bubble‑tight at operating pressure.
• Pressure and end‑connection guidance: selection of pressure ratings and compatibility of inlet/outlet ratings and end connections (references to commonly used ANSI and MIL standards where applicable).
• Units and conventions: inch‑pound units are primary; SI conversions provided for information only.

Typical use and users

Used by valve manufacturers, test laboratories, designers and specifiers of compressed gas systems, and facilities that handle pressurized air or nitrogen where rapid isolation is required after a downstream failure (laboratories, industrial gas systems, medical gas distribution, compressed‑air utilities, mobile and fixed equipment). Procurement, quality and compliance teams use the standard to specify acceptance testing and functional performance.

Related standards

Referenced normative documents and related guidance commonly cited with F1793 include ANSI B16.34 (flanged/threaded/welded valve standards), ANSI B1.20.1 (pipe threads), ANSI B1.1 (UN threads), ANSI B16.25 (butt welding ends), MIL‑F‑1183 and various MIL/MIL‑STD vibration and shock references; other ASTM F committee documents on valve labeling and valve components may be used alongside F1793 for broader procurement and testing requirements.

Keywords

automatic shut‑off valve, excess flow valve, EFV, air service, nitrogen service, set‑point test, hydrostatic shell test, seal tightness, leakage test, valve specification, ANSI B16.34, compressed gas safety.

FAQ

Q: What is this standard?

A: ASTM F1793-97(2021) is an ASTM International specification that defines requirements and tests for self‑contained automatic shut‑off (excess flow) valves intended for air or nitrogen service.

Q: What does it cover?

A: It covers valve types, styles, sizes, pressure ratings, end connections and prescribes required tests (visual, hydrostatic shell, seal tightness, external leakage and set‑point) and performance tolerances relevant to automatic shut‑off behavior. Inch‑pound units are primary; SI conversions are informational.

Q: Who typically uses it?

A: Valve manufacturers, test labs, system designers, maintenance and safety engineers, procurement/specification authors, and any organization that needs to ensure automatic shut‑off valves for air or nitrogen meet defined safety and performance criteria.

Q: Is it current or superseded?

A: The original standard was issued in 1997 and has recorded reapproval/reconfirmation entries; the standard is listed as active with the most recent update/reconfirmation entry shown in 2021 (designation presented as F1793‑97(2021)). Users should check ASTM records for any amendments or newer revisions beyond the 2021 reapproval before formal procurement.

Q: Is it part of a series?

A: It is part of the ASTM F committee portfolio for valves and related equipment (developed by Subcommittee F25.11) and is often referenced alongside general valve and piping standards (ANSI/MIL references listed in F1793). It is a standalone specification for automatic shut‑off valves but sits within the broader ASTM/industry valve standards ecosystem.

Q: What are the key keywords?

A: Excess flow valve (EFV), automatic shut‑off valve, air, nitrogen, set‑point, hydrostatic test, leakage, valve specification, ANSI B16.34.