ISO 4437-1:2024 気体燃料供給用のプラスチック配管システム | ページ 6

3.1.1

呼び径

DN/OD

外径に関係する部品のサイズの数値指定

注記 1:製造寸法をミリメートル (mm) 単位で表した、便宜上の概数です。ねじサイズで指定された部品には適用されません。

3.1.2

呼び外径

d _n

呼び径に割り当てられた指定外径 (3.1.1)

注記 1:呼び外径はミリメートル (mm) で表されます。

3.1.3

公称壁厚

e _n

コンポーネントの壁厚の数値指定。これは製造寸法 (mm) にほぼ等しい便利な概数です。

注記 1: ISO 4437 シリーズに準拠する熱可塑性プラスチック部品の場合、公称肉厚e _n の値は、 任意の点で指定された最小肉厚 (3.1.5) と同一です。

3.1.4

任意の点での壁の厚さ

e

コンポーネントの円周上の任意の点における肉厚を次に大きい 0.1 mm に四捨五入したもの

注記 1:継手およびバルブ本体の任意の点における肉厚の記号はE です。

3.1.5

任意の点における最小の壁の厚さ

e _​

コンポーネントの周囲の 任意の点 (3.1.4) における肉厚 の最小値

3.1.6

標準寸法比

SDR

パイプシリーズの数値指定 (3.1.7) 。 これは 呼び外径 (3.1.2) と 呼び肉厚 (3.1.3) の寸法比にほぼ等しい便利な概数です。

3.1.7

パイプシリーズ

S

パイプ指定番号

3.2.1

compound

homogenous extruded mixture of base polymer (3.2.2) (polyethylene) and additives (i.e. anti-oxidants, pigments, carbon black, UV-stabilizers and others) at a dosage level necessary for the processing and use of components

3.2.2

base polymer

polymer produced by the material supplier for the manufacture of the compound (3.2.1)

3.3.1

lower confidence limit of the predicted hydrostatic strength

σ_LPL

quantity, with the dimensions of stress, that represents the 97,5 % lower confidence limit of the predicted hydrostatic strength at temperature θ and time t

Note 1 to entry: It is expressed in megapascals (MPa).

3.3.2

minimum required strength

MRS

value of the lower confidence limit of the predicted hydrostatic strength (3.3.1) at 20 °C and 50 years, rounded down to the next smaller value of the R10 series or the R20 series

Note 1 to entry: Only compounds (3.2.1) with an MRS of 8 MPa or 10 MPa are specified in this document.

Note 2 to entry: The R10 series and the R20 series conform to ISO 3.

Note 3 to entry: It is expressed in megapascals (MPa).

[SOURCE:ISO 12162:2009, 3.3, modified — Note 1 to entry has been removed and replaced with new Notes 1 to 3 to entry.]

3.3.3

design coefficient

C

coefficient with a value greater than 1 which takes into consideration service conditions as well as properties of the components of a piping system other than those represented in the lower confidence limit of the predicted hydrostatic strength (3.3.1)

3.3.4

design stress

σ_s

allowable stress for a given application at 20 °C that is derived from the minimum required strength, MRS (3.3.2) , by dividing it by the design coefficient, C (3.3.3)

Note 2 to entry: It is expressed in megapascals (MPa).

3.3.5

melt mass-flow rate

MFR

value relating to the viscosity of the molten material at a specified temperature and load

Note 1 to entry: It is expressed in grams per 10 minutes (g/10 min).

3.4.1

gaseous fuel

fuel which is in gaseous state at a temperature of 15 °C at atmospheric pressure

Note 1 to entry: There are proposals to inject gases from renewable sources in natural gas networks, e.g. hydrogen (H₂). This is the subject of ongoing research.

3.4.2

maximum operating pressure

MOP

maximum effective pressure of the fluid in the piping system which is allowed in continuous use

Note 2 to entry: Research on long-term performance prediction of polyethylene gas distribution systems shows a possible service life of at least 100 years; see References [14], [15] and [16].

3.4.3

reference temperature

temperature for which the piping system is designed

Note 1 to entry: It is used as the base for further calculation when designing a piping system or parts of a piping system for operating temperatures different from the reference temperature (see ISO 4437-5).

3.4.4

manufactured gas

synthetic gas

gas which has been treated and can contain components that are not typical of natural gas

Note 1 to entry: Manufactured (synthetic) gases can contain substantial amounts of chemical species that are not typical of natural gases or common species found in atypical proportions as in the case of wet and sour gases.

[SOURCE:ISO 14532:2014, 2.1.1.4]

3.5.1

butt fusion joint

joint made by heating the planed ends of pipes or spigot end fittings (3.5.6) , the surfaces of which are fused together by holding them against a flat heating plate until the polyethylene material reaches fusion temperature, removing the heating plate quickly and pushing the two softened ends against one another

3.5.2

fusion compatibility

ability of two similar or dissimilar polyethylene compounds (3.2.1) to be fused together to form a joint

3.5.3

electrofusion joint

joint between a polyethylene electrofusion socket fitting (3.5.4) or electrofusion saddle fitting (3.5.5) and a pipe or spigot end fitting (3.5.6) , made by heating the electrofusion fitting by the Joule effect of the heating element incorporated at their jointing surfaces, causing the material adjacent to them to melt, and the pipe and fitting surfaces to fuse

3.5.4

electrofusion socket fitting

polyethylene (PE) fitting which contains one or more integrated heating elements that are capable of transforming electrical energy into heat to realize a fusion joint with a spigot end or a pipe

3.5.5

electrofusion saddle fitting

polyethylene (PE) fitting which contains one or more integrated heating elements that are capable of transforming electrical energy into heat to realize a fusion joint onto a pipe

3.5.6

spigot end fitting

polyethylene (PE) fitting where the outside diameter of the spigot end is equal to the nominal outside diameter (3.1.2) of the corresponding pipe