ASTM E911-98 (2021) PDF

Full title and description

ASTM E911-98 (Reapproved 2021) — Standard Specification for Glass Stopcocks with Polytetrafluoroethylene (PTFE) Plugs. Specifies standard dimensional requirements to achieve practical interchangeability of glass stopcocks fitted with PTFE plugs for ordinary laboratory and industrial applications; covers dimensional, taper and leak/performance requirements but does not address glass stopcocks with glass plugs or stopcocks intended for high‑vacuum service.

Abstract

This specification defines geometry and dimensional tolerances for a range of glass stopcock types (single straight‑bore, single oblique‑bore, double oblique/three‑way, T‑bore, angled‑bore) when used with PTFE (Types I and IV, extrusion and molding grades) plugs. It establishes interchangeability limits, taper requirements, and test methods for dimensions, taper, leak rate and basic performance. It excludes glass‑plug stopcocks and high‑vacuum applications and references related ASTM materials and laboratory‑glass standards.

General information

• Status: Published — reapproved (current) as of 2021
• Publication date: Current edition approved January 1, 2021; published February 2021 (designation E911−98, reapproved 2021).
• Publisher: ASTM International (formerly American Society for Testing and Materials)
• ICS / categories: 71.040.20 — Laboratory ware and related apparatus
• Edition / version: Designation E911−98 (Reapproved 2021) — often cited as ASTM E911-98(2021)
• Number of pages: 4 pages (short specification)

Scope

The specification covers standard dimensional requirements to obtain interchangeability of glass stopcocks fitted with PTFE plugs for ordinary laboratory and industrial applications. It addresses only dimensional interchangeability and related dimensional tests (including taper and leak‑rate checks) and does not set requirements for design features outside dimensions or for the physical/chemical properties of materials beyond the PTFE resin grades specified. Exclusions: glass stopcocks with glass plugs and stopcocks intended for high‑vacuum use.

Key topics and requirements

• Dimensional interchangeability limits for multiple stopcock types (single straight, single oblique, double oblique/3‑way, T‑bore, angled‑bore).
• Specified PTFE plug material: Types I and IV (extrusion and molding grade resins).
• Taper requirement for bores and plugs (specified nominal taper, with tight tolerance, e.g., approximately 2 mm per 10 mm of length with defined tolerance).
• Dimensional measurement methods (micrometer/caliper accuracy and test procedures).
• Measured tests for taper (sine bar/air gage or equivalent) and leak rate (prescribed test arrangement and acceptance criteria).
• Performance testing guidance for assembly interchangeability (function under normal laboratory/industrial conditions).
• Referenced related ASTM specifications for glass materials, PTFE resins and packaging/testing of laboratory apparatus.

Typical use and users

Used by manufacturers of laboratory glassware and stopcocks, quality assurance and inspection personnel, laboratory procurement and specification writers, instrument and apparatus designers, and standards compliance officers. Typical uses include specifying interchangeable stopcocks for glassware assemblies, acceptance testing for incoming stopcocks, and purchasing/specification language for lab equipment vendors.

Related standards

Commonly referenced ASTM standards and practices associated with E911 include: ASTM E438 (Glasses in Laboratory Apparatus), ASTM E671 (Maximum Permissible Thermal Residual Stress in Annealed Glass Laboratory Apparatus), ASTM E675 (Interchangeable Taper‑Ground Stopcocks and Stoppers), ASTM D1457 (PTFE molding and extrusion materials), and packaging/performance standards such as ASTM E920, E921, E1133 and E1157. Users should consult the latest editions of those documents for full cross‑requirements.

Keywords

glass stopcock, PTFE plug, stopcock dimensions, dimensional interchangeability, taper specification, leak rate test, laboratory glassware, ASTM E911

FAQ

Q: What is this standard?

A: ASTM E911-98 (Reapproved 2021) is a short ASTM specification that sets standard dimensional and interchangeability requirements for glass stopcocks fitted with PTFE plugs used in ordinary laboratory and industrial applications.

Q: What does it cover?

A: It covers dimensions, tolerances, taper requirements, and basic test methods for dimensions, taper and leak/performance for several stopcock types; it does not cover glass stopcocks with glass plugs, high‑vacuum stopcocks, or detailed material chemistry beyond the PTFE grades specified.

Q: Who typically uses it?

A: Manufacturers, QA/inspection teams, laboratory equipment purchasers, specification writers and designers of laboratory glass assemblies use the standard to ensure interchangeability and to define acceptance testing for stopcocks with PTFE plugs.

Q: Is it current or superseded?

A: The designation is E911−98 with a reapproval in 2021 (commonly cited as ASTM E911-98(2021)). As reapproved in 2021 it remains an active/current ASTM specification; users should confirm whether a newer revision has been released before final procurement or regulatory reliance.

Q: Is it part of a series?

A: It is maintained by ASTM Committee E41 (Laboratory Apparatus) and complements a set of laboratory glassware standards (for example, E438, E671 and E675) that together cover materials, stress limits, and related interchangeability/specification topics.

Q: What are the key keywords?

A: Glass stopcock, PTFE plug, interchangeability, taper, leak test, laboratory glassware, ASTM E911.