ISO 16486-1:2020 ガス燃料供給用のプラスチック配管システム—溶融接合および機械的接合を備えた非可塑化ポリアミド（PA-U）配管システム—パート1：一般 | ページ 6

3.1.1

呼び外径

d_n

最小平均外径 (3.1.4) d_em,minと同一である、構成部品の指定外径。

グレード 1 ～ エントリー: mm で表されます。

3.1.2

任意の点の外径

d_e

パイプの任意の点、または継手のスピゴット端の断面を通して測定した外径で、最も近い 0.1 mm に切り上げたもの

3.1.3

平均外径

_demd

パイプの外周または継手のインロー端の測定長さを π (≈3.142) で割った値を 0.1 mm 単位で切り上げたもの

3.1.4

最小平均外径

d_、分

所定の公称サイズについて規定された 平均外径（3.1.3） の最小値。

3.1.5

最大平均外径

d_、最大

所定の公称サイズについて規定された 平均外径（3.1.3） の最大値。

3.1.6

呼び肉厚

e_n

最小肉厚e_minに対応する肉厚 (mm)

3.1.7

任意の点での壁の厚さ

e

コンポーネントの周囲の任意の点で測定された壁の厚さを、最も近い 0.1 mm に切り上げます

3.1.8

任意の点での最小肉厚

e_分

指定された構成部品の周囲の 任意の点（3.1.7）における肉厚 の最小値。

3.1.9

標準寸法比

SDR

パイプの 公称外径 (3.1.1) d_nと公称肉厚e_nの比。

3.2.1

compound

homogenous mixture of base polymer (PA-U) and additives, i.e. antioxidants, pigments, UV stabilisers, at a dosage level necessary for the processing and use of components conforming to the requirements of this document

3.2.2

rework material

material from a manufacturer's own production (of compounds [3.2.1] and of pipes, fittings or valves) that has been reground or pelletized for reuse by that same manufacturer

3.3.1

lower confidence limit of the predicted hydrostatic strength

σ_LPL

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

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

Note 2 to entry: Temperature, θ, is expressed in degrees Celsius and time, t, is expressed in years.

3.3.2

minimum required strength

MRS

value of σ_LPL (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: The R10 series conforms to ISO 3 ^[5] and the R20 series conforms to ISO 497 ^[6].

3.3.3

categorized required strength at temperature θ and time t

CRS _θ,t

value of σ_LPL (3.3.1) at temperature θ and time t, rounded down to the next smaller value of the R10 series or the R20 series

Note 1 to entry: CRS _θ,t at 20 °C and 50 years equals MRS (3.3.2).

Note 2 to entry: Temperature, θ, is expressed in degrees Celsius and time, t, is expressed in years.

Note 3 to entry: The R10 series conforms to ISO 3 ^[5] and the R20 series conforms to ISO 497 ^[6].

3.3.4

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

3.3.5

design stress

σ_s

σ_s,θ,t

stress derived by dividing the MRS (3.3.2) or CRS _θ,t(3.3.3) by the design coefficient (3.3.4) , C, i.e. σ_s = MRS/C, or σ_s,θ,t = CRS _θ,t/C

3.4.1

gaseous fuel

any fuel which is in a gaseous state at a temperature of 15 °C, at a pressure of one bar (0,1 MPa)

3.4.2

maximum operating pressure

MOP

maximum effective pressure of the gas in the piping system, expressed in bar, which is allowed in continuous use

Note 1 to entry: The MOP takes into account the physical and the mechanical characteristics of the components of a piping system and the influence of the gas on these characteristics.