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VOLUNTARY PRODUCT STANDARDS
Voluntary Product Standards are standards developed under procedures established by the Department of Commerce (15 CFR Part 10, as amended, May 28, 1970). The standards may include (1) dimensional requirements for standard sizes and types of various products, (2) technical requirements, and (3) methods of testing, grading, and marking. The objective of a Voluntary Prod. uct Standard is to establish requirements which are in accordance with the principal demands of the industry and, at the same time, are not contrary to the public interest.
Development of a VOLUNTARY PRODUCT STANDARD The Office of Engineering Standards Services of the National Bureau of Standards has been assigned by the Department of Commerce the responsibility to work closely with scientific and trade associations and organizations, business firms, testing laboratories, and other appropriate groups to develop Voluntary Product Standards. The Bureau has the following role in the development process: It (1) provides editorial assistance in the preparation of the standard; (2) supplies such assistance and review as is required to assure the technical soundness of the standard; (3) acts as an unbiased coordinator in the development of the standard; (4) sees that the standard is representative of the views of producers, distributors, and users or consumers; (5) seeks satisfactory adjustment of valid points of diagreement; (6) determines the compliance with the criteria established in the Department's procedures cited above; and (7) publishes the standard. Industry customarily (1) initiates and participates in the development of a standard; (2) provides technical counsel on a standard; and (3) promotes the use of, and support for, the standard. (A group interested in developing a Voluntary Product Standard may submit a written request to the Office of Engineering Standards Services, National Bureau of Standards, Washington, D.C. 20234.)
A draft of a proposed standard is developed in consultation with interested trade groups. Subsequently, a Standard Review Committee is established to review the proposed standard. The committee, appropriately balanced, includes qualified representatives of producers, distributors, and users or consumers of the product being standardized. When the committee approves a proposal, copies are distributed for industry consideration and acceptance. When the acceptances show general industry agreement, and when there is no substantive objection deemed valid by the Bureau, the Bureau announces approval of the Voluntary Product Standard and proceeds with its publication.
Use of a VOLUNTARY PRODUCT STANDARD
The adoption and use of a Voluntary Product Standard is completely voluntary. Voluntary Product Standards have been used most effectively in conjunction wtih legal documents such as sales contracts, purchase orders, and building codes. When a standard is made part of such a document, compliance with the standard is enforceable by the purchaser or the seller along with other provisions of the document.
Voluntary Product Standards are useful and helpful to purchasers, manufacturers, and distributors. Purchasers may order products that comply with Voluntary Product Standards and determine for themselves that their requirements are met. Manufacturers and distributors may refer to the standards in sales catalogs, advertising, invoices, and labels on their product. Commercial inspection and testing programs may also be employed, together with grade labels and certificates assuring compliance, to promote even greater public confidence. Such assurance of compliance promotes better understanding between purchasers and sellers.
Voluntary Product Standard PS 52-71
Effective November 15, 1971 (See section 6.)
(This Standard, initiated by The Society of the Plastics Industry, Inc., has been developed under the Procedures for the Development of Voluntary Broduct Standards, published by the U.S. Department of Commerce. See Section 7, History of Project, for further information.)
The purpose of this Voluntary Product Standard is to establish nationally recognized dimensions and significant quality requirements for plastic tubing when made of polytetrafluoroethylene (PTFE) resin and intended for electrical, chemical, and mechanical applications. This Standard is intended to provide producers, distributors, and users with a basis for common understanding of the characteristics of this product.
2. SCOPE AND CLASSIFICATION
2.1. Scope—This Voluntary Product Standard covers commercially available PTFE tubing intended for chemical, mechanical, and electrical applications. It provides requirements and methods of test for materials, dimensions, and physical and chemical properties. A method for identifying products which comply with this Standard is provided.
2.2. Classification—The plastic tubing covered by this Standard is classified as follows:
Grade A This grade of PTFE tubing is intended for electrical
uses. There are no subtypes or subclasses. Grade BThis grade of PTFE tubing is intended for chemical
and mechanical uses. There are two subtypes and
three subclasses for each subtype: Type 1—This type of PTFE tubing has wall thicknesses
ranging from 0.040 inch to 0.070 inch. Type II—This type of PTFE tubing has wall thicknesses
ranging from 0.030 inch to 0.055 inch.
Type I and Type II include the following classes:
Class A-general-purpose tubing.
bility and fatigue resistance.
3.1. General—Products represented as complying with this Voluntary Product Standard shall meet all of the requirements specified herein.
3.2. Material—The tubing shall be made of polytetrafluoroethylene (PTFE) resin conforming to the requirements of Type III resin as described in the American Society for Testing and Materials (ASTM) D 1457-69, Standard Specification for TFEFluorocarbon Resin Molding and Extrusion Materials, except that a maximum of 2 percent by weight of additive is permissible.
3.3. Dimensions and tolerances—The dimensions and tolerances of the tubing shall be as specified in table 1 or 2 when the tubing is measured in accordance with 4.3.
1 Later issues of the ASTM publications referenced in this Standard may be used providing the requirements are applicable and consistent with the issues designated. Copies of ASTM publications are obtainable from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103. TABLE 1. Dimensions and tolerances for Grade A PTFE plastic tubing Descriptive size Inside diameter
Wall thickness American
(plus or (AWG) Fractional Minimum Maximum Nominal minus) Number Inch Inch
.004 18 .125 .135 .020
.005 70 .438 .464 .025
.005 142 .500 .524 .025
.005 .625 .655 .030
.006 4 .750 .786 .035
.007 .875 .911 .035
.007 1 1.000 1.036 .035
TABLE 2. Dimensions and tolerances for Grade B PTFE plastic tubing
3.4. Melting point—The tubing shall have a melting point as specified in table 3 when tested in accordance with 4.4.
3.5. Specific gravity-The tubing shall have a specific gravity as specified in table 3 when tested in accordance with 4.5.
3.6. Tensile strength and elongation—The tubing shall have a tensile strength and elongation as specified in table 3 when tested in accordance with 4.6.
TABLE 3. Physical requirements for PTFE tubing
Dimenat 200% Elonga- Weightsional elonga- tion loss change
% % % Grade A-Electrical 327 + 10 °C 2.13 to
(621 + 18 °F) 2.24 3000 200 0.50 1.0 Grade B—Chem. &
purpose (621 + 18 °F) 2.13 2000 200 0.05 1.0 Class B-Rexible 327 + 10 °C 2.13 to
(621 + 18 °F) 2.18 2000 200 0.05 Class C-stress- 327 + 10 °C over
relieved (621 + 18 °F) 2.18 1800 200 0.05 1.5
3.7. Weight loss—The tubing shall have a maximum weight loss as specified in table 3 when tested in accordance with 4.7.
3.8. Dimensional stability-The tubing shall have a maximum percent change in any dimension as specified in table 3 when tested in accordance with 4.8.