GB/T 28799.1-2012 English PDF (GBT28799.1-2012)

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GB/T 28799.1-2012: Plastics piping systems for hot and cold water installations -- Polyethylene of raised temperature resistance (PE-RT) -- Part 1: General
GB/T 28799.1-2012
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.040.01; 91.140.60
G 33
Plastics piping systems for hot and cold water
installations - Polyethylene of raised temperature
resistance (PE-RT) - Part 1: General
ISSUED ON: NOVEMBER 05, 2012
IMPLEMENTED ON: MARCH 01, 2013
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Terms, definitions, symbols, abbreviations ... 5 
4 Grades of use conditions ... 11 
5 Materials ... 12 
6 Hygienic requirements ... 13 
Appendix A (Normative) PE-RT predicted hydrostatic strength reference curve
... 14 
References ... 17 
Plastics piping systems for hot and cold water
installations - Polyethylene of raised temperature
resistance (PE-RT) - Part 1: General
1 Scope
This part of GB/T 28799 specifies the terms and definitions, symbols and
abbreviations, grades of use conditions, materials, hygiene requirements for
plastics piping systems for hot and cold water installations - polyethylene of
raised temperature resistance (PE-RT).
This part applies to piping systems which are produced by the PE-RT type-I and
PE-RT type-II materials.
This part is used in conjunction with GB/T 28799.2 and GB/T 28799.3. It is
suitable for hot and cold water piping systems for buildings, including cold and
hot water, drinking water, heating systems for civil and industrial buildings.
This part does not apply to fire suppression systems.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) are applicable to this standard.
GB/T 6111 Thermoplastics pipes for the conveyance of fluids - Resistance
to internal pressure - Test method (ISO 1167)
GB/T 17219 Standard for safety evaluation of equipment and protective
materials for drinking water supply and distribution
GB/T 18252 Plastics piping and ducting systems - Determination of the long-
term hydrostatic strength of thermoplastics materials in pipe form by
extrapolation (ISO 9080)
GB/T 18991 Thermoplastics pipes and fittings for hot and cold water systems
(ISO 10508)
GB/T 19278 General terms and their definitions of thermoplastic pipes,
of any cross-section of the pipe or fitting’s socket by 3.142 (π) and rounded
off to 0.1 mm to the great circle.
3.1.1.4
Minimum mean outside diameter
dem,min
The minimum allowable value of the mean outside diameter.
3.1.1.5
Maximum mean outside diameter
dem,max
The maximum allowable value of the mean outside diameter.
3.1.1.6
Mean inside diameter of socket
dsm
The mean inside diameter of the specified part (middle) of the socket, in mm.
3.1.1.7
Out-of roundness; ovality
On the same cross-section of the tubular portion of the pipe or fitting, the
difference between the maximum and minimum measured values of outside
diameter, or the difference between the maximum and minimum measured
bore.
3.1.1.8
Nominal wall thickness
en
The specified value of the wall thickness of the pipe, which is equal to the
minimum allowable wall thickness ey,min, in mm.
3.1.1.9
Wall thickness at any point
3.1.2.1
Design pressure
pD
Design value of the pressure of piping system, in megapascals (MPa).
3.1.2.2
Maximum allowable operating pressure
pPMS
The maximum operating pressure of a fluid in a piping system that allows
continuous use.
3.1.2.3
Hydrostatic stress
When the water is used as the medium and the pipe is subjected to internal
pressure, the ring stress in the pipe wall, which is approximated by the
formula (2), in MPa.
Where:
p - The internal pressure of the pipe, in Megapascal (MPa);
dem - The mean outside diameter of the pipe, in millimeters (mm);
emin - The minimum wall thickness of the pipe, in millimeters (mm).
3.1.2.4
Design temperature
TD
The design value of the temperature of water delivery system, in °C.
3.1.2.5
Maximum design temperature
Note: It may refer to Appendix A of GB/T 28799.2-2012.
3.1.3.3
Overall service (design) coefficient
A value greater than 1, the size of which takes into account the conditions of
use and the influence of the characteristics of other accessories in the
pipeline to the piping system, which is the safety margin of the piping system
considered in addition to the factors included in the lower confidence limit.
3.1.3.4
Pipe with barrier layer
Plastic pipe which has a very thin barrier, to prevent or reduce gas or light
transmission through the pipe wall, whilst the requirements for design stress
are all guaranteed by the body resin (PE-RT).
3.2 Symbol
The following symbols apply to this document.
C: Overall service (design) coefficient (C), dimensionless
de: Outside diameter at any point
dem: Mean outside diameter
dem,min: Minimum mean outside diameter
dem,max: Maximum mean outside diameter
dn: Nominal outside diameter
dsm: Mean inside diameter of socket
e: Wall thickness at any point
emax: Maximum wall thickness
emin: Minimum wall thickness
en: Nominal wall thickness
p: Internal hydrostatic pressure
pD: Design pressure
pPMS: Maximum allowable operating pressure
T: Temperature
Tcold: Cold water temperature
TD: Design temperature
Tmal: Malfunction temperature
Tmax: Maximum design temperature
t: Time
σ: hydrostatic stress
σcold: Design stress at 20 °C
σD: Design stress
σDP: Design stress of pipe material
σP: Hydrostatic stress of pipe material
σLPL: Lower confidence limit of the predicted hydrostatic strength
3.3 Abbreviations
The following abbreviations apply to this document.
PE-RT type-I: Type-I heat-resistant polyethylene
PE-RT type-II: Type-II heat-resistant polyethylene
S: Pipe series
4 Grades of use conditions
4.1 The heat-resistant polyethylene (PE-RT) piping system adopts the
provisions of GB/T 18991. It selects four grades of use conditions (1, 2, 3, 4)
from it according to the use conditions, as shown in Table 1. Each grade
corresponds specific scope of application and 50-year design service life. In
actual use, it shall also consider different design pressures of 0.4 MPa, 0.6 MPa,
0.8 MPa, 1.0 MPa.