ASTM E911-98(2021)

Standard Specification for Glass Stopcocks with Polytetrafluoroethylene (PTFE) Plugs

ABSTRACT
This specification covers dimensional interchangeability requirements of glass stopcocks with polytetrafluoroethylene (PTFE) plugs for use in ordinary laboratory and industrial applications. However, it does not cover the design characteristics of the stopcock-plug assembly nor the physical or chemical properties of the materials used. Glass stopcocks with glass plugs or stopcocks for use in high-vacuum applications are not covered as well. The plug shall be manufactured from PTFE material of Types I and IV, extrusion and molding grade resins. Stopcocks, on the other hand, shall be manufactured from glass into one of various types: single straight-bore stopcock, single oblique-bore stopcock, double oblique-bore (three-way) stopcock, T-bore stopcock, or angled-bore stopcock. Tests for dimension conformity, taper, leak rate, and performance shall be performed and shall conform to the requirements specified.
SCOPE
1.1 This specification covers standard dimensional requirements for obtaining, within practical limits, interchangeability in glass stopcocks (Note 1) with polytetrafluoroethylene (PTFE) plugs for ordinary laboratory and industrial applications. It covers dimensional interchangeability only and does not involve design characteristics of the item except where specified, nor does it involve physical or chemical characteristics of the material used. It does not cover glass stopcocks with glass plugs (Note 2) or stopcocks intended for use in high-vacuum work.  
Note 1: A stopcock is defined as consisting of a plug and barrel in assembled configuration.
Note 2: Glass stopcocks with glass plugs are covered by Specification E675.
Note 3: The dimensions pertaining to stopcocks were taken from the now obsolete Commercial Standard CS 21-58 of the U.S. Department of Commerce and Product Standard PS 28-70 published by the National Bureau of Standards.
Note 4: Although glass is the most common material for stopcocks, other materials may be used as specified. Stopcocks constructed from glass shall be in accordance with Specifications E438 and E671.  
1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Dec-2020
• ICS: 71.040.20 - Laboratory ware and related apparatus
• Technical Committee: E41 - Laboratory Apparatus
• Drafting Committee: E41.01 - Laboratory Ware and Supplies

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:E911 −98 (Reapproved 2021)
Standard Specification for
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Glass Stopcocks with Polytetrafluoroethylene (PTFE) Plugs
This standard is issued under the fixed designation E911; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
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1. Scope Molding and Extrusion Materials (Withdrawn 1996)
E438 Specification for Glasses in Laboratory Apparatus
1.1 This specification covers standard dimensional require-
E671 Specification for Maximum Permissible Thermal Re-
ments for obtaining, within practical limits, interchangeability
sidual Stress in Annealed Glass Laboratory Apparatus
in glass stopcocks (Note 1) with polytetrafluoroethylene
E675 Specification for Interchangeable Taper-Ground Stop-
(PTFE) plugs for ordinary laboratory and industrial applica-
cocks And Stoppers
tions. It covers dimensional interchangeability only and does
E920 Specification for Commercially Packaged Laboratory
not involve design characteristics of the item except where
Apparatus
specified, nor does it involve physical or chemical character-
E921 Specification for Export Packaged Laboratory Appa-
istics of the material used. It does not cover glass stopcocks
ratus
with glass plugs (Note 2) or stopcocks intended for use in
E1133 Practice for Performance Testing of Packaged Labo-
high-vacuum work.
ratory Apparatus for United States Government Procure-
NOTE 1—A stopcock is defined as consisting of a plug and barrel in
ments
assembled configuration.
E1157 Specification for Sampling and Testing of Reusable
NOTE 2—Glass stopcocks with glass plugs are covered by Specification
Laboratory Glassware
E675.
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2.2 Other Standard:
NOTE 3—The dimensions pertaining to stopcocks were taken from the
now obsolete Commercial Standard CS 21-58 of the U.S. Department of PS 28-70 Glass Stopcocks With Polytetrafluoroethylene
Commerce and Product Standard PS 28-70 published by the National
(PTFE) Plugs
Bureau of Standards.
NOTE 4—Although glass is the most common material for stopcocks,
3. Material
other materials may be used as specified. Stopcocks constructed from
glass shall be in accordance with Specifications E438 and E671. 3.1 The PTFE material used to manufacture the plugs shall
be in accordance with the requirements of Specification D1457
1.2 This international standard was developed in accor-
Types I and IV, extrusion and molding grade resins.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Requirements for Single Straight-Bore Stopcocks
Development of International Standards, Guides and Recom-
4.1 The designations and dimensions for single straight-
mendations issued by the World Trade Organization Technical
bore stopcocks are shown in Fig. 1 and Table 1.
Barriers to Trade (TBT) Committee.
4.2 Taper (Note 3)—All straight-bore stopcocks shall have a
2. Referenced Documents
taper of 2 6 0.006 mm of diameter per 10 mm of length (1 to
2
5).
2.1 ASTM Standards:
D374 Test Methods for Thickness of Solid Electrical Insu-
NOTE 5—The lines of contact of the mating surfaces should form a
lation (Metric) D0374_D0374M conical section having a taper of 2 6 0.006 mm per 1 cm of axial length
(before compression of the plug surface) for an axial distance of at least
D1457 Specification for Polytetrafluoroethylene (PTFE)
10 mm on each side of the bore.
5. Requirements for Single Oblique-Bore Stopcocks
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This specification is under the jurisdiction of ASTM Committee E41 on
5.1 The designations and dimensions for single oblique-
Laboratory Apparatus and is the direct responsibility of Subcommittee E41.01 on
bore stopcocks are shown in Fig. 2 and Table 2.
Laboratory Ware and Supplies.
Current edition approved Jan. 1, 2021. Published February 2021. Originally
approvedin1982.Lastpreviouseditionapprovedin2015asE911 – 98(2015).DOI:
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10.1520/E0911-98R21. The last approved version of this historical standard is referenced on
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or www.astm.org.
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the ASTM website. Gaithersburg, MD 20899-1070, http://www.nist.gov.
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