Polyethylene of raised temperature resistance (PE-RT) piping systems for hot and cold water installations - Part 4: Valves
1 Scope
This document specifies the materials, classification, models, specifications and dimensions, deviations, physical and mechanical property requirements, inspection rules, markings, packaging, transportation, and storage of polyethylene of raised temperature resistance valves for hot and cold water installations (hereinafter referred to as "valves"), and describes the corresponding test methods.
This document is applicable to the manufacturing and inspection of ball valves made of PE-RT II material with a nominal dimension not exceeding 40 mm.
In conjunction with the other parts of GB/T28799, this document is applicable to hot and cold water piping systems, including domestic hot and cold water, drinking water and heating systems, hot spring water piping systems, and centralized heating secondary pipe network systems for civil and industrial buildings.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 2918 Plastics - Standard atmospheres for conditioning and testing
GB/T 3682.1 Plastics - Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics - Part 1:Standard method
GB/T 8806 Plastics piping systems - Plastics components - Determination of dimensions
GB/T 9345.1 Plastics - Determination of ash - Part 1: General methods
GB/T 12670-2008 Polyproplene (PP) resin
GB/T 17219 Standard for safety evaluation of equipment and protective materials in drinking water system
GB/T 18251 Method for the assessment of the degree of pigment or carbon black dispersion in polyolefin pipes, fittings and compounds
GB/T 19278 General terms and their definitions of thermoplastic pipes, fittings and valves
GB/T 19466.6 Plastics - differential scanning calorimetry (DSC) - Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)
GB/T 19993 Thermoplastics piping systems for hot and cold water supply - Test method for the resistance of pipes and fittings mounted assemblies to thermal cycling
GB/T 21300 Plastics pipes and fittings - Determination of opacity
GB/T 21465 Terminology of valves
GB/T 22271.2 Plastics - Polyoxymethylene(POM) moulding and extrusion materials - Part 2: Preparation of test specimens and determination of properties
GB/T 22271.3 Plastics - Polyoxymethylene (POM) moulding and extrusion materials - Part 3: Requirements for general materials
GB/T 27572-2011 Rubber seals - Joint rings for pipelines for hot-water supply up to 110°C - Specification for the materials
GB/T 27726 Thermoplastics valves - Pressure test methods and requirements
GB/T 28799.1-2020 Plastics piping systems for hot and cold water installations - Polyethylene of raised temperature resistance (PE-RT) - Part 1: General
GB/T 28799.2 Plastics piping systems for hot and cold water installations - Polyethylene of raised temperature resistance (PE-RT) - Part 2: Pipes
GB/T 28799.3 Plastics piping systems for hot and cold water installations - Polyethylene of raised temperature resistance (PE-RT) - Part 3: Fittings
GB/T 28799.5 Plastics piping systems for hot and cold water installations - Polyethylene of raised temperature resistance (PE-RT) - Part 5: Fitness for purpose of the system
GB/T 37842 Ball valves of thermoplastics materials
3 Terms and definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 19278, GB/T 21465, GB/T 28799.1 and GB/T 37842 as well as the following apply.
3.1.1
nominal diameter
DN
nominal value of the valve connection port
Note: The nominal dimension of a valve is characterized by the nominal outside diameter of the pipes used in conjunction with the valve.
[Source: GB/T 19278-2018, 2.3.4, modified]
3.1.2
shell
pressure-bearing components in direct contact with medium
[Source: GB/T 21465-2008, 2.3.2.1]
3.1.3
minimum flow area
minimum cross-sectional area of the fluid flow path between the inlet and outlet ends of the valve
[Source: GB/T 37842-2019, 3.3.13, modified]
3.1.4
operating torque
maximum torque required to fully open or close the valve under the specified pressure
3.1.5
stop strength
maximum torque that the limiting device can withstand after operating the valve to the limit position
3.1.6
strength of opening and closing device
maximum torque that the ball, stem, and valve cap can withstand
3.2 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in GB/T 28799.1-2020 apply.
4 Materials
4.1 PE-RT II materials
4.1.1 The performance of PE-RT II material used for valve shell shall meet those specified in Table 2 and Table 3 of GB/T 28799.1-2020. When the pipeline is connected by hot melt, it shall meet the welding compatibility requirements in subclause 5.3 of GB/T 28799.1-2020.
4.1.2 PE-RT II materials shall not use recycled or reprocessable materials.
Contents
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions, symbols and abbreviated terms
4 Materials
5 Model designation
6 Requirements
7 Fitness for purpose of the system
8 Test methods
9 Inspection rules
10 Marking, packaging, transport and storage
Annex A (Normative) Test method for operating torque
Annex B (Normative) Test method for tensile
Annex C (Normative) Test method for impact resistance
