ASTM F336-02(2023)

Standard Practice for Design and Construction of Nonmetallic Enveloped Gaskets for Corrosive Service

SIGNIFICANCE AND USE
3.1 The gaskets covered by this practice can be used on, but are not limited to, equipment constructed of the following materials: (a) stoneware, (b) glass and glass-lined, (c) tantalum (solid and lined), (d) titanium (solid and lined or clad), (e) zirconium (solid and lined or clad), (f) silver (solid and lined), and (g) nickel and nickel alloys (solid and clad).  
3.2 The gaskets provided for herein are for the following: (a) pipe flanges (flat or raised face), (b) vessel nozzles, (c) circular openings in vessels in excess of 12 in. (305 mm) diameter, and (d) oval openings in vessels.
SCOPE
1.1 This practice covers the designs, sizes, classifications, and construction of enveloped gaskets for severe corrosive applications. The envelope serves as the corrosion resistant member of the composite gasket and is a nonmetallic material such as polytetrafluoroethylene, PTFE, or related materials. The inserts are nonmetallic gasketing materials with or without metal reinforcement. Other types of composite gaskets are covered in Classification F868.  
1.2 This standard is based directly upon ANSI B16.21–2011; for that reason units are as ANSI stated in inches.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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-Mar-2023
• ICS: 21.140 - Seals, glands
• Technical Committee: F03 - Gaskets
• Drafting Committee: F03.10 - Composite Gaskets

Relations

• Refers: ASTM F104-11(2020) - Standard Classification System for Nonmetallic Gasket Materials
• Effective Date: 01-Jan-2020
• Refers: ASTM F112-00(2019) - Standard Test Method for Sealability of Enveloped Gaskets
• Effective Date: 01-May-2019
• Refers: ASTM F868-17 - Standard Classification for Laminated Composite Gasket Materials
• Effective Date: 01-May-2017
• Refers: ASTM F112-00(2013) - Standard Test Method for Sealability of Enveloped Gaskets
• Effective Date: 01-May-2013
• Refers: ASTM D3308-12 - Standard Specification for PTFE Resin Skived Tape
• Effective Date: 01-Aug-2012
• Refers: ASTM F104-11 - Standard Classification System for Nonmetallic Gasket Materials
• Effective Date: 01-Apr-2011
• Refers: ASTM D3294-09 - Standard Specification for PTFE Resin Molded Sheet and Molded Basic Shapes
• Effective Date: 01-Nov-2009
• Refers: ASTM F104-03(2009) - Standard Classification System for Nonmetallic Gasket Materials
• Effective Date: 01-Oct-2009
• Refers: ASTM F868-02(2009) - Standard Classification for Laminated Composite Gasket Materials
• Effective Date: 01-May-2009
• Refers: ASTM F112-00(2006) - Standard Test Method for Sealability of Enveloped Gaskets
• Effective Date: 01-Oct-2006
• Refers: ASTM D3308-06 - Standard Specification for PTFE Resin Skived Tape
• Effective Date: 01-Apr-2006
• Refers: ASTM F104-03 - Standard Classification System for Nonmetallic Gasket Materials
• Effective Date: 10-Apr-2003
• Refers: ASTM D3294-03 - Standard Specification for PTFE Resin Molded Sheet and Molded Basic Shapes
• Effective Date: 10-Apr-2003
• Refers: ASTM F868-02 - Standard Classification for Laminated Composite Gasket Materials
• Effective Date: 10-Oct-2002
• Refers: ASTM F104-02e1 - Standard Classification System for Nonmetallic Gasket Materials
• Effective Date: 10-Oct-2002

Overview

ASTM F336-02(2023), titled Standard Practice for Design and Construction of Nonmetallic Enveloped Gaskets for Corrosive Service, offers comprehensive criteria for designing, sizing, and constructing enveloped gaskets intended for severe corrosive environments. This international standard specifies requirements for nonmetallic enveloped gaskets composed primarily of corrosion-resistant materials such as PTFE (polytetrafluoroethylene) and similar substances. Its framework covers gaskets used in conjunction with equipment fabricated from diverse materials, including stoneware, glass-lined metals, tantalum, titanium, zirconium, silver, and nickel alloys. The practice is crucial for industrial applications where high chemical resistance and sealing integrity are essential.

Key Topics

• Gasket Design and Classification: The standard details designs (split, machined, folded) for enveloped gaskets and classifies insert constructions as single or multi-layer, with further grades based on material composition and layering.
• Materials: The envelope functions as the primary corrosion barrier, typically composed of nonmetallic materials like PTFE. Inserts can be of various nonmetallic gasket materials, sometimes with metallic supports, selected based on the demands of the corrosive environment.
• Applicable Equipment: Enveloped gaskets as per ASTM F336-02(2023) are suitable for pipe flanges (flat or raised face), vessel nozzles, large circular and oval vessel openings, enhancing versatility across process piping and containment systems.
• Sizing and Dimensions: This standard references ANSI B16.21–2011 for dimensional criteria, ensuring compatibility with standard pipe flange sizes. Gasket sizes are provided in inches as per ANSI conventions.
• Testing and Inspection: Recommendations are provided for material suitability, sealability (ASTM F112), and electrical inspection methods to verify corrosion-resistant characteristics post-manufacturing.
• Construction Guidelines: Advice is offered on avoiding elastomeric inserts prone to creep, and on appropriate layering of materials to balance sealing performance and ease of installation.

Applications

The ASTM F336-02(2023) standard supports industries that require reliable sealing in the presence of aggressive chemicals and corrosive fluids. This includes:

• Chemical Processing: Ensures compatibility with harsh acids, solvents, and reagents in glass-lined and exotic-metal equipment.
• Pharmaceutical Manufacturing: Maintains hygienic, leak-free containment where vessel and piping systems must withstand cleaning agents and reactants.
• Petrochemical and Refining: Provides robust sealing for high-purity and high-pressure service in systems built from corrosion-resistant alloys.
• Food and Beverage: Useful where nonmetallic sealing prevents metal contamination and supports sanitary processes.
• Water Treatment: Vital for membranes and distribution pipes exposed to strong oxidizers or corrosive waters.
• General Industrial: Applicable wherever durable, chemical-resistant flange or vessel sealing is necessary.

Related Standards

For harmonized implementation and extended compatibility, refer to these related standards:

• ASTM F104: Classification System for Nonmetallic Gasket Materials
• ASTM F868: Classification for Laminated Composite Gasket Materials
• ASTM D3294: Specification for PTFE Resin Molded Sheet and Molded Basic Shapes
• ASTM D3308: Specification for PTFE Resin Skived Tape
• ASTM F112: Test Method for Sealability of Enveloped Gaskets
• ASME B16.21–2011: Nonmetallic Flat Gaskets for Pipe Flanges

By following ASTM F336-02(2023), organizations can ensure the integrity, safety, and operational lifespan of gaskets in highly corrosive service. This standard supports the selection and construction of enveloped nonmetallic gaskets, driving reliable and sustainable industrial sealing solutions aligned with international best practices.

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: F336 − 02 (Reapproved 2023)
Standard Practice for
Design and Construction of Nonmetallic Enveloped Gaskets
for Corrosive Service
This standard is issued under the fixed designation F336; 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.
1. Scope F868 Classification for Laminated Composite Gasket Mate-
rials
1.1 This practice covers the designs, sizes, classifications,
2.2 Other Document:
and construction of enveloped gaskets for severe corrosive
ASME B16.21 – 2011 Nonmetallic Flat Gaskets for Pipe
applications. The envelope serves as the corrosion resistant
Flanges
member of the composite gasket and is a nonmetallic material
such as polytetrafluoroethylene, PTFE, or related materials.
3. Significance and Use
The inserts are nonmetallic gasketing materials with or without
metal reinforcement. Other types of composite gaskets are 3.1 The gaskets covered by this practice can be used on, but
covered in Classification F868. are not limited to, equipment constructed of the following
materials: (a) stoneware, (b) glass and glass-lined, (c) tantalum
1.2 This standard is based directly upon ANSI
(solid and lined), (d) titanium (solid and lined or clad), (e)
B16.21–2011; for that reason units are as ANSI stated in
zirconium (solid and lined or clad), (f) silver (solid and lined),
inches.
and (g) nickel and nickel alloys (solid and clad).
1.3 This standard does not purport to address all of the
3.2 The gaskets provided for herein are for the following:
safety concerns, if any, associated with its use. It is the
(a) pipe flanges (flat or raised face), (b) vessel nozzles, (c)
responsibility of the user of this standard to establish appro-
circular openings in vessels in excess of 12 in. (305 mm)
priate safety, health, and environmental practices and deter-
diameter, and (d) oval openings in vessels.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
4. Sizes
dance with internationally recognized principles on standard-
4.1 The gasket nominal size listed in inches, Table 1, will be
ization established in the Decision on Principles for the
the same as used on the following pipe flanges in accordance
Development of International Standards, Guides and Recom-
with ASME B16.21 – 2011:
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
Pipe Size ASME
⁄2 to 24 in. B16.21 – 1992, Table 5 and 6
2. Referenced Documents
Over 24 in. B16.21 – 1992, Table 1 and 2
2.1 ASTM Standards:
4.2 Commercial dimensional tolerances apply, unless other-
D3294 Specification for Polytetrafluoroethylene (PTFE)
wise agreed upon between the seller and the purchaser.
Resin Molded Sheet and Molded Basic Shapes
5. Materials and Manufacture
D3308 Specification for PTFE Resin Skived Tape
F104 Classification System for Nonmetallic Gasket Materi-
5.1 The gaskets covered by this practice shall be made of
als
nonmetallic materials, except when a metal support is desired
F112 Test Method for Sealability of Enveloped Gaskets
in the insert.
5.2 Materials should be selected, both for inserts and
envelopes, that will withstand the conditions under which they
This practice is under the jurisdiction of ASTM Committee F03 on Gaskets and
are to be subjected in service.
is the direct responsibility of Subcommittee F03.10 on Composite Gaskets.
Current edition approved April 1, 2023. Published April 2023. Originally
5.3 A list of reference literature for determining material
approved in 1971. Last previous edition approved in 2016 as F336 – 02 (2016).
suitability in corrosive environments is available from ASTM
DOI: 10.1520/F0336-02R23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from American Society of Mechanical Engineers, Three Park
the ASTM website. Avenue, New York, NY 10016.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F336 − 02 (2023)
A
TABLE 1 Nominal Gasket Sizes
NOTE 1—Refer to Fig. 1 through Fig. 6 for explanation of gasket
component details.
NOTE 2—Split design inserts not to be smaller than nominal pipe size.
NOTE 3—Inside diameter of folded and machined design envelopes will
adjoin the insert inside diameter assuring noninterference with flow
through pipe.
NOTE 4—Full face gaskets shall have envelope outside diameter same
as ring gasket outside diameter.
NOTE 5—Sizes 14 in. (356 mm) and larger may be made from machined
envelopes depending upon material shape availability.
Insert (2) (See Note 1) Envelope (1) (See Note 1)
IV. Flat
III. Full
Ring
Nominal II. Inside Face V. (Each VI. Inside
Gasket VII. Outside
Pipe Diameter Outside Side) Diameter
Outside Diameter (C)
Size, in. (B) Diameter Thickness (A)
Diameter
(D)
(C)
in. in. in. in. in. in.
⁄2 0.84 3.50 1.88 0.015 0.50 1.88
⁄4 1.06 3.88 2.25 0.015 0.75 2.25
1 1.31 4.25 2.62 0.020 1.00 2.62
1 ⁄4 1.66 4.63 3.00 0.020 1.25 3.00
1 ⁄2 1.91 5.00 3.38 0.020 1.50 3.38
2 2.38 6.00 4.12 0.020 2.00 4.12
FIG. 1 Split Design (Fla
...