ASTM D7194-19
Standard Specification for Aerospace Parts Machined from Polychlorotrifluoroethylene (PCTFE)

Standard No.

ASTM D7194-19

Release Date

2019

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM D7194-19

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 high molecular weight, good molecular weight retention during processing, dimensional stability, controlled crystallinity, 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°C (160°F), 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 13, 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. NOTE 1—There is no known ISO equivalent to this standard. 1.10 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.

ASTM D7194-19 Referenced Document

• ASTM D1204 Standard Test Method for Linear Dimensional Changes of Nonrigid Thermoplastic Sheeting or Film at Elevated Temperature
• ASTM D1430 Standard Classification System for Polychlorotrifluoroethylene (PCTFE) Plastics*， 2022-03-15 Update
• ASTM D1600 Standard Terminology for Abbreviated Terms Relating to Plastics
• ASTM D1708 Standard Test Method for Tensile Properties of Plastics By Use of Microtensile Specimens
• ASTM D2512 Standard Test Method for Compatibility of Materials with Liquid Oxygen (Impact Sensitivity Threshold and Pass-Fail Techniques)
• ASTM D3045 Standard Practice for Heat Aging of Plastics Without Load
• ASTM D4591 Standard Test Method for Determining Temperatures and Heats of Transitions of Fluoropolymers by Differential Scanning Calorimetry
• ASTM D618 Standard Practice for Conditioning Plastics for Testing*， 2021-07-15 Update
• ASTM D638 Standard Test Method for Tensile Properties of Plastics
• ASTM D7211 Standard Specification for Parts Machined from Polychlorotrifluoroethylene (PCTFE) and Intended for General Use*， 2023-05-17 Update
• ASTM D792 Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
• ASTM D883 Standard Terminology Relating to Plastics*， 2024-02-01 Update
• ASTM G86 Standard Test Method for Determining Ignition Sensitivity of Materials to Mechanical Impact in Ambient Liquid Oxygen and Pressurized Liquid and Gaseous Oxygen Environments

ASTM D7194-19 history

• 2019 ASTM D7194-19 Standard Specification for Aerospace Parts Machined from Polychlorotrifluoroethylene (PCTFE)
• 2012 ASTM D7194-12 Standard Specification for Aerospace Parts Machined from Polychlorotrifluoroethylene (PCTFE)
• 2005 ASTM D7194-05 Standard Specification for Aerospace Parts Machined from Polychlorotrifluoroethylene