ISO 2531:2009 ダクタイル鋳鉄管、継手、付属品、および水用途のそれらの接合部 | ページ 5

3.1

accessory

any casting other than a pipe or fitting, which is used in a pipeline

Note 1 to entry: The term accessory is not relevant for valves or hydrants of any type.

3.2

allowable operating pressure

PFA

maximum internal pressure, excluding surge, which a component can safely withstand in permanent service

3.3

allowable site test pressure

PEA

maximum hydrostatic pressure that a newly installed component can withstand for a relatively short duration, when either fixed above ground level or laid and backfilled underground, in order to measure the integrity and tightness of the pipeline

Note 1 to entry: This test pressure is different from the system test pressure, which is related to the design pressure of the pipeline.

3.4

batch

quantity of castings from which a sample may be taken for testing purposes during manufacture

3.5

component

any product defined as an element of a pipe, fitting or accessory

3.6

deviation

amount by which the design length may differ from the standardized length of a pipe or a fitting

Note 1 to entry: Pipes and fittings are designed to a length selected in the range of standard length plus or minus the deviation (see Table 6); they are manufactured to this length plus or minus the tolerance given in Table 7.

3.7

diametral stiffness of a pipe

characteristic of a pipe allowing it to resist diametral deflection under loading

3.8

ductile iron

type of cast iron used for pipes, fittings and accessories in which graphite is present primarily in spheroidal form

3.9

fitting

casting other than a pipe, which allows pipeline deviation, change of direction or bore

Note 1 to entry: Flanged sockets, flanged spigots and collars are also classified as fittings.

3.10

flange

end of a pipe or fitting, extending perpendicular to its axis, with bolt holes equally spaced in a circle

Note 1 to entry: A flange can be fixed (e.g. integrally cast, screwed-on or welded-on) or adjustable. An adjustable flange comprises a ring, in one or several parts bolted together, which bears on an end joint hub and which can be freely rotated around the barrel axis before jointing.

3.11

flanged joint

joint between two flanged ends

3.12

flexible joint

joint providing significant angular deflection and movement parallel and/or perpendicular to the pipe axis

3.13

gasket

sealing component of a joint

3.14

hoop stress

σ

stress in a pipe or fitting under pressure, acting tangentially to the perimeter of a transverse section

3.15

joint

connection between the ends of pipes and/or fittings in which a gasket is used to effect a seal

3.16

laying length

L_e

length by which a pipeline progresses when an additional pipe is installed

Note 1 to entry: For socket and spigot pipes, it is equal to the total length of the pipe, L_tot, minus the maximum spigot insertion depth, L_i, as given by the manufacturer and as shown in Figure 4. For flanged pipes, it is equal to the total length of the pipe.

Note 2 to entry: It is expressed in metres.

3.17

maximum allowable operating pressure

PMA

maximum internal pressure, including surge, which a component can safely withstand in service

3.18

mechanical flexible joint

flexible joint in which sealing is obtained by applying pressure to the gasket by mechanical means

3.19

nominal pressure

PN

numerical designation, which is a convenient rounded number, used for reference purposes

Note 1 to entry: All components of the same nominal size, DN, designated by the same PN number have compatible mating dimensions.

Note 2 to entry: Adapted from ISO 7268.

3.20

nominal size

DN

alphanumeric designation of size for components of a pipework system, which is used for reference purposes

Note 1 to entry: It comprises the letters DN followed by a dimensionless whole number, which is indirectly related to the physical size, in millimetres, of the bore or outside diameter of the end connections.

Note 2 to entry: Adapted from ISO 6708:1995, definition 2.1.

3.21

ovality

3.22

pipe

casting of uniform bore, with straight axis, having either socket, spigot or flanged ends

Note 1 to entry: This does not apply to flanged sockets, flanged spigots and collars, which are classified as fittings.

3.23

push-in flexible joint

flexible joint assembled by pushing the spigot through the gasket into the socket of the mating component

3.24

restrained joint

joint in which a means is provided to prevent separation of the assembled joint

3.25

socket

female end of a pipe or fitting to make the connection with the spigot of the next component

3.26

spigot

male end of a pipe or fitting

3.27

spigot end

maximum insertion depth of the spigot, L_i, plus 50 mm

3.28

standardized length

length of pipe barrel and fitting body or branch as defined in this International Standard

Note 1 to entry: For socket and spigot pipes, and fittings, it is designated L_u ( l_u for branches). For flanged pipes, and fittings, it is designated L ( l for branches). See Figures 4 to 27.

Note 2 to entry: For flanged pipes and fittings, the standardized length L ( l for branches) is equal to the total length. For socketed pipes and fittings, the standardized length L_u ( l_u for branches) is equal to the total length minus the spigot insertion depth, as indicated in the manufacturer’s catalogues.

3.29

type test

proof-of-design test, which is done once and is repeated only after change of design