ASTM D7194-12
(Specification)Standard Specification for Aerospace Parts Machined from Polychlorotrifluoroethylene (PCTFE)
Standard Specification for Aerospace Parts Machined from Polychlorotrifluoroethylene (PCTFE)
ABSTRACT
This specification establishes the requirements for parts intended for aerospace use and machined from polychlorotrifluoroethylene (PCTFE) homopolymers. This specification, however, does not cover parts machined from PCTFE copolymer, PCTFE film or tape, or modified PCTFE. Material covered by this specification is on four types, differentiated based on intended uses and exposures: Types I (high service pressure) and II (low service pressure) for use in air and oxygen media, Type II for use in inert and reactive media, and Type IV for use in other media. The parts shall be manufactured from virgin, unplasticized, pure PCTFE homopolymer, and the use of recycled polymer or regrind shall be prohibited. The base material shall be free of defects and contaminants. The finished parts shall be white or gray in color with a natural translucent appearance, and shall be free of voids, scratches, fissures, inclusions, or entrapped air bubbles. Tests for specific gravity, melting point, tensile strength and elongation, deformation under load, zero strength time, mechanical impact (in ambient liquid oxygen and pressurized liquid and gaseous oxygen environments), and dimensional stability shall be performed and shall conform to the requirements specified.
SCOPE
1.1 This specification is intended to be a means of calling out finished machined parts ready for aerospace use. Such parts may also find use in selected commercial applications where there are clear benefits derived from the use of parts with known or controlled crystallinity, high molecular weight, good molecular weight retention during processing, dimensional stability in the finished part, and tightly controlled engineering tolerances.
1.2 This specification establishes requirements for parts machined from virgin, unplasticized, 100 % polychlorotrifluoroethylene (PCTFE) homopolymers.
1.3 This specification does not cover parts machined from PCTFE copolymers, PCTFE film or tape less than 0.25-mm (0.010-in.) thick, or modified PCTFE (containing pigments or plasticizers).
1.4 This specification does not allow parts containing recycled material.
1.5 The specification does not cover PCTFE parts intended for general use applications, in which control of dimensional stability, molecular weight, and crystallinity are not as important. For machined PCTFE parts intended for general use, use Specification D7211.
1.6 This specification classifies parts into three classes based upon intended uses and exposures: oxygen-containing media, reactive media, and inert media.
1.7 Application—PCTFE components covered by this specification are virgin, 100 % PCTFE resin, free of plasticizers and other additives. The components are combustion resistant in oxygen, dimensionally stable, and meet other specific physical characteristics appropriate for their end use. They are used in valves, regulators, and other devices in oxygen, air, helium, nitrogen, hydrogen, ammonia, and other aerospace media systems. The components typically are used as valve seats, o-rings, seals, and gaskets. They are removed and replaced during normal maintenance procedures. The components provide reliable sealing surfaces resulting in proper closure of valves and related devices and no leakage from the system into the environment. They will experience static mechanical loading, cyclic mechanical loading, temperatures ranging from cryogenic to 71 ºC (160 ºF), and pressures up to 68.9 MPa (10,000, psig) for oxygen and air media, and 103.4 MPa (15,000 psig) for inert media.
1.8 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.9 The following precautionary caveat pertains only to the test methods portion, Section 12, of this specification: 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 safet...
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D7194 −12
Standard Specification for
Aerospace Parts Machined from Polychlorotrifluoroethylene
1
(PCTFE)
This standard is issued under the fixed designation D7194; 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 o-rings, seals, and gaskets. They are removed and replaced
during normal maintenance procedures. The components pro-
1.1 This specification is intended to be a means of calling
vide reliable sealing surfaces resulting in proper closure of
outfinishedmachinedpartsreadyforaerospaceuse.Suchparts
valves and related devices and no leakage from the system into
may also find use in selected commercial applications where
the environment. They will experience static mechanical
there are clear benefits derived from the use of parts with
loading, cyclic mechanical loading, temperatures ranging from
known or controlled crystallinity, high molecular weight, good
cryogenic to 71 ºC (160 ºF), and pressures up to 68.9 MPa
molecular weight retention during processing, dimensional
(10,000, psig) for oxygen and air media, and 103.4 MPa
stability in the finished part, and tightly controlled engineering
(15,000 psig) for inert media.
tolerances.
1.8 The values stated in SI units are to be regarded as
1.2 This specification establishes requirements for parts
standard. The values in parentheses are for information only.
machined from virgin, unplasticized, 100 % polychlorotrifluo-
1.9 The following precautionary caveat pertains only to the
roethylene (PCTFE) homopolymers.
test methods portion, Section 12, of this specification: This
1.3 This specification does not cover parts machined from
standard does not purport to address all of the safety concerns,
PCTFE copolymers, PCTFE film or tape less than 0.25-mm
if any, associated with its use. It is the responsibility of the user
(0.010-in.) thick, or modified PCTFE (containing pigments or
of this standard to establish appropriate safety and health
plasticizers).
practices and to determine the applicability of regulatory
1.4 This specification does not allow parts containing re-
limitations prior to use.
cycled material.
NOTE 1—There is no known ISO equivalent to this standard.
1.5 The specification does not cover PCTFE parts intended
for general use applications, in which control of dimensional
2. Referenced Documents
stability, molecular weight, and crystallinity are not as impor-
2
2.1 ASTM Standards:
tant. For machined PCTFE parts intended for general use, use
D618 Practice for Conditioning Plastics for Testing
Specification D7211.
D638 Test Method for Tensile Properties of Plastics
1.6 This specification classifies parts into three classes
D792 Test Methods for Density and Specific Gravity (Rela-
based upon intended uses and exposures: oxygen-containing
tive Density) of Plastics by Displacement
media, reactive media, and inert media.
D883 Terminology Relating to Plastics
D1430 ClassificationSystemforPolychlorotrifluoroethylene
1.7 Application—PCTFEcomponentscoveredbythisspeci-
(PCTFE) Plastics
fication are virgin, 100 % PCTFE resin, free of plasticizers and
D1600 Terminology forAbbreviatedTerms Relating to Plas-
other additives. The components are combustion resistant in
tics
oxygen, dimensionally stable, and meet other specific physical
D1708 Test Method forTensile Properties of Plastics by Use
characteristics appropriate for their end use. They are used in
of Microtensile Specimens
valves, regulators, and other devices in oxygen, air, helium,
D2512 Test Method for Compatibility of Materials with
nitrogen, hydrogen, ammonia, and other aerospace media
Liquid Oxygen (Impact Sensitivity Threshold and Pass-
systems. The components typically are used as valve seats,
Fail Techniques)
1
This specification is under the jurisdiction of ASTM Committee D20 on
Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic
2
Materials. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2012. Published November 2012. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2005. Last previous edition approved in 2005 as D5111 - 05. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7194-12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7194−12
D4591 Test Method for Determining Temperatures and 4.2.3 Type III for use in media other than air, oxygen, GHe,
Heats of Transitions of F
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7194 − 05 D7194 − 12
Standard Specification for
Aerospace Parts Machined from Polychlorotrifluoroethylene
1
(PCTFE)
This standard is issued under the fixed designation D7194; 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
1.1 This specification is intended to be a means of calling out finished machined parts ready for aerospace use. Such parts may
also find use in selected commercial applications where there are clear benefits derived from the use of parts with known or
controlled crystallinity, high molecular weight, good molecular weight retention, retention during processing, dimensional stability
in the finished part, and tightly controlled engineering tolerances.
1.2 This specification establishes requirements for parts machined from virgin, unplasticized, 100 % 100 % polychlorotrifluo-
roethylene (PCTFE) homopolymers.
1.3 This specification does not cover parts machined from PCTFE copolymers, PCTFE film or tape less than 0.25-mm
(0.010-in.) thick, or modified PCTFE (containing pigments or plasticizers).
1.4 This specification does not allow parts containing recycled material.
1.5 The specification does not cover PCTFE parts intended for general use applications, in which control of dimensional
stability, molecular weight, and crystallinity are not as important. For machined PCTFE parts intended for general use, use
Specification D7211.
1.6 This specification classifies parts into three classes based upon intended uses and exposures: oxygen-containing media,
reactive media, and inert gases.media.
1.7 Application—PCTFE components covered by this specification are virgin, 100 % 100 % PCTFE resin, free of plasticizers
and other additives. The components are combustion resistant in oxygen, dimensionally stable, and meet other specific physical
characteristics appropriate for their end use. They are used in valves, regulators, and other devices in oxygen, air, helium, nitrogen,
hydrogen, ammonia, and other aerospace media systems. The components typically are used as valve seats, o-rings, seals, and
gaskets. They are removed and replaced during normal maintenance procedures. The components provide reliable sealing surfaces
resulting in proper closure of valves and related devices and no leakage from the system into the environment. They will experience
static mechanical loading, cyclic mechanical loading, temperatures ranging from cryogenic to 71ºC (160ºF), 71 ºC (160 ºF), and
pressures up to 46.2 MPa (6700 psi).68.9 MPa (10,000, psig) for oxygen and air media, and 103.4 MPa (15,000 psig) for inert
media.
1.8 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.9 The following precautionary caveat pertains only to the test methods portion, Section 12, of this specification: 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 and health practices and to determine the applicability of regulatory limitations prior to
use.
NOTE 1—There is no known ISO equivalent to this standard.
2. Referenced Documents
2
2.1 ASTM Standards:
D621D618 Specification for Jute Rove and Plied Yarn for Electrical and Packing PurposesPractice for Conditioning Plastics for
Testing (Withdrawn 2000)
1
This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials.
Current edition approved July 1, 2005Oct. 1, 2012. Published August 2005November 2012. Originally approved in 2005. Last previous edition approved in 2005 as
D5111 - 05. DOI: 10.1520/D7194-05.10.1520/D7194-12.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7194 − 12
D638 Test Method for Tensile Properties of Plastics
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D883 Terminology Re
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.