GB/T 19278-2018General terms and their definitions of thermoplastic pipes, fittings and valves (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 19278-2003 "General terms and definitions of thermoplastic pipes, fittings and valves". And GB/T 19278- Compared with.2003, the main technical changes are as follows.

---Adjusted the concept system. the terms are related to materials, related to product structure, related to size and size, related to product characteristics And five parts (subsets) related to the application;

--- Re-determined the location of each concept and related definitions;

--- Removed homopolypropylene, random copolymer polypropylene, block copolymer polypropylene, cross-linked polyethylene, non-plasticized polyvinyl chloride, 20 ° C, 50 years of lower confidence limit, 20 ° C, 50 years long-term strength and other terms and definitions (see.2003 edition 5.4~5.8, 5.10, 5.12);

--- Increased terms and definitions for hydrostatic strength, graded strength (see 2.1);

--- Added parts, multi-layer pipes, composite pipes, reinforced thermoplastic composite pipes, fiber reinforced plastic pipes, molecularly oriented polyvinyl chloride pipes, Barrier pipe, cladding pipe, functional layer, socket, pipe fitting with insert, steel-plastic conversion pipe fitting, inspection well, secondary processing and valve Related terms and definitions (see 2.2);

--- Added nominal size DN/OD, nominal size DN/ID, nominal size WN/HN, (any point) inner diameter, joint length, most Terms and definitions of small bending radius, size group, nominal value; average diameter modified to medium diameter, nominal diameter of socket is modified to Weigh the inner diameter (see 2.3);

--- Removed the terms and definitions of the maximum roundness, minimum wall thickness and maximum wall thickness of the socket (see.2003 edition 3.15, 3.19, 3.20);

--- Increased longitudinal bending stiffness, ring flexibility, compression cracking stability, longitudinal retraction, opening and closing torque, flow coefficient, rated flow system Terms and definitions of the number, relative flow coefficient, and inherent flow characteristics (see 2.4);

--- Increased internal pressure, working pressure, design pressure, design temperature, cold water temperature, temperature-to-pressure reduction factor, fusion compatibility, Terminology and definition of elastic socket connection, bonding, electrofusion connection, hot melt connection, hot melt butt joint; leakage damage modified to leak; 2.5.1)

--- Removed cylindrical socket, tapered socket, mechanical connection pipe fitting, elastic sealing pipe fitting, solvent bonding pipe fitting, hot melt butt pipe Terms and definitions of pieces, hot melt socket fittings (see.2003 editions 4.6~4.10, 4.12, 4.13);

--- Added terms and definitions related to pipeline repair and renewal, irrigation and high pressure oil and gas pipelines (see 2.5.2~2.5.4);

--- Added the informative appendix "The relationship between pipeline pressure resistance and long-term hydrostatic test results" (see Appendix A);

--- Added English corresponding word index.

Introduction

Plastic pipe and valve products industry is linked to and through plastic raw materials, molding processing, product structure design, quality assurance, engineering design and Key industries in applications such as applications require a systematic terminology to facilitate inter-industry communication and standardization.

This standard has collected more than 300 standard documents in ISO, ASTM, China national standards and major industry standards systems.

The important criteria are listed in the reference), and more than 3,000 terms were analyzed and screened to determine and redefine more than 160 of the standard. Terms.

This standard pays attention to controlling the total amount while moderately expanding the professional field. On the one hand, some of the simple techniques that can be "as the name suggests" are deleted.

Language, intentionally reducing the "long terminology" of compound word formation, choosing the word root or less root terminology of derivation (word formation ability);

Extract the essential characteristics of the concept, sum up and refine the upper concept, and give only the typical terms or ambiguous terms to the subordinate concept. surface. At the same time, in order to take care of and cover the terminology needs of emerging applications, some representative areas of expertise such as special composites have also been selected.

Engineering application terminology such as structural piping, irrigation, and pipeline repair.

For the sake of simplicity and ease of use, abbreviations are given for compound phrase long terms, such as "the lower confidence limit for predicting long-term hydrostatic strength". "lower limit of prediction", etc.; for the concept of a different meaning (or a polysemous) of the same name (such as "nominal size"), the use of Chinese characters in English characters Way, by adding feature information into multiple parallel terms to achieve single-list meaning (for example, "nominal size DN/OD" "nominal size DN/ID"). For ease of understanding, this standard has written a large number of notes.

Due to the intersection of the concepts of many terms, different architectures may be obtained according to different classification criteria, thus affecting the terminology.

The location in the conceptual system. This standard adopts the basic principles of system ordering, focusing on refining the concepts of higher levels and reducing the underlying concepts.

Some genera relationships are treated as associations, and the hierarchy is diluted to simplify the text.

The creep properties and long-term pressure resistance of plastic pipes are different from those of traditional pipes, which may cause misunderstandings by users. Appendix A of this standard The relationship between concepts is further explained. Appendix B helps to quickly find the Chinese meaning of symbols and abbreviations.

1 Scope

This standard defines the general terminology and definition of thermoplastic pipes, fittings and valves.

This standard applies to the design, manufacture, inspection, application and standardization of thermoplastics and some thermoset plastic pipes, fittings and valves. Other related fields.

2 Terms and definitions