ISO 7121:2016
(Main)Steel ball valves for general-purpose industrial applications
Steel ball valves for general-purpose industrial applications
ISO 7121:2016 specifies the requirements for a series of steel ball valves suitable for general-purpose industrial applications. It covers valves of the nominal sizes - DN 8, 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, and 600 (NPS 1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2, 2, 21/2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20 and 24), and is applicable to the following pressure designations: - PN 10; 16; 25; 40; 63; 100; - Class 150; 300; 600; 800; 900. NOTE Valve characteristics are not necessarily available in all nominal sizes for all pressure designations. For example, Class 800 applies only for valves with threaded end and socket weld ends up to DN 65 (NPS 21/2) and Class 900 applies only for reduced bore body seat openings. It includes provisions for valve characteristics as follows: - flanged and butt-welded ends in sizes 15 ≤ DN ≤ 600 (1/2 ≤ NPS ≤ 24); - socket welding ends in sizes 8 ≤ DN ≤ 100 (1/4 ≤ NPS ≤ 4); - threaded ends in sizes 8 ≤ DN ≤ 50 (1/4 ≤ NPS ≤ 2); - body seat openings designated as full bore, reduced bore and double reduced bore; - materials; - testing and inspection.
Robinets en acier à tournant sphérique pour les applications industrielles générales
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 7121
Third edition
2016-04-15
Steel ball valves for general-purpose
industrial applications
Robinets en acier à tournant sphérique pour les applications
industrielles générales
Reference number
ISO 7121:2016(E)
©
ISO 2016
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ISO 7121:2016(E)
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ii © ISO 2016 – All rights reserved
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ISO 7121:2016(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Pressure/temperature ratings . 3
4.1 Valve rating . 3
4.2 Shell rating . 3
4.3 Seat and seal rating . 3
5 Design . 4
5.1 Flow passageway . 4
5.2 Body . 5
5.2.1 Body wall thickness . 5
5.2.2 Flanged ends . . 8
5.2.3 Butt-welding ends. 8
5.2.4 Socket welding ends . 8
5.2.5 Threaded ends . 9
5.2.6 Body openings . 9
5.2.7 Anti-static design . 9
5.2.8 Anti-blow-out stem .10
5.2.9 Ball-stem construction .10
5.2.10 Ball construction .10
5.2.11 Operating means .10
5.2.12 Glands .11
5.2.13 End flange facing interruptions .11
5.2.14 Shell joints .12
5.2.15 Packing gland bolting .13
6 Materials .13
6.1 Shell .13
6.2 Shell material repair .14
6.3 Trim .14
6.4 Identification plate .14
6.5 Bolting .14
6.6 Seals .14
6.7 Threaded plugs .14
7 Marking .14
7.1 Legibility .14
7.2 Body marking .14
7.3 Ring joint marking .15
7.4 Identification plate .15
7.5 Special marking for unidirectional valves .15
8 Testing and inspection .16
8.1 Pressure tests .16
8.1.1 General.16
8.1.2 Shell test .16
8.1.3 Closure tightness test . .16
8.2 Inspection .17
8.3 Examination.17
8.4 Supplementary examination .18
9 Preparation for despatch .18
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ISO 7121:2016(E)
Annex A (informative) Information to be specified by the purchaser .19
Annex B (informative) Identification of valve parts .20
Bibliography .22
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ISO 7121:2016(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 153, Valves.
This third edition cancels and replaces the second edition (ISO 7121:2006), which has been technically
revised with the following changes:
— in the scope DN 600, NPS 20 and 24, Class 800 and a note on the applicability of this Class were added;
— the normative references were updated;
— definitions for DN, NPS, PN and Class were added;
— a line for DN 600 was added in Table 2;
— a line for DN 600 and a column for Class 800 were added in Table 3;
— a column for DN 600 was added in Table 4;
— a column for Class 800 was added in Table 6;
— in Tables 7 and 8, DN is up to 600;
— in 5.2.12.3, vertically split glands are not allowed anymore; Annex A was updated accordingly;
— 8.2.2 on site inspection was deleted; Annex A was updated accordingly.
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ISO 7121:2016(E)
Introduction
The purpose of this International Standard is the establishment, in ISO format, of basic requirements
and practices for flanged, butt-welding, socket welding and threaded-end steel ball valves having flow
passageways identified as full bore, reduced bore and double reduced bore, suitable for general purpose
applications. Flanged end Class designated valves have flanges in accordance with ASME B16.5.
Flanged end PN designated valves have flanges in accordance with EN 1092-1. Valves with ends that are
threaded can have threads to either ISO 7-1 or ASME B1.20.1.
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INTERNATIONAL STANDARD ISO 7121:2016(E)
Steel ball valves for general-purpose industrial
applications
1 Scope
This International Standard specifies the requirements for a series of steel ball valves suitable for
general-purpose industrial applications.
It covers valves of the nominal sizes
— DN 8, 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, and 600 (NPS 1/4,
3/8, 1/2, 3/4, 1, 11/4, 11/2, 2, 21/2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20 and 24),
and is applicable to the following pressure designations:
— PN 10; 16; 25; 40; 63; 100;
— Class 150; 300; 600; 800; 900.
NOTE Valve characteristics are not necessarily available in all nominal sizes for all pressure designations.
For example, Class 800 applies only for valves with threaded end and socket weld ends up to DN 65 (NPS 21/2)
and Class 900 applies only for reduced bore body seat openings.
It includes provisions for valve characteristics as follows:
— flanged and butt-welded ends in sizes 15 ≤ DN ≤ 600 (1/2 ≤ NPS ≤ 24);
— socket welding ends in sizes 8 ≤ DN ≤ 100 (1/4 ≤ NPS ≤ 4);
— threaded ends in sizes 8 ≤ DN ≤ 50 (1/4 ≤ NPS ≤ 2);
— body seat openings designated as full bore, reduced bore and double reduced bore;
— materials;
— testing and inspection.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 7-1, Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances
and designation
ISO 7-2, Pipe threads where pressure-tight joints are made on the threads — Part 2: Verification by means
of limit gauges
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,
tolerances and designation
ISO 228-2, Pipe threads where pressure-tight joints are not made on the threads — Part 2: Verification by
means of limit gauges
ISO 261, ISO general purpose metric screw threads — General plan
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ISO 7121:2016(E)
ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general
purpose external and internal screw threads — Medium quality
ISO 4032, Hexagon regular nuts (style 1) — Product grades A and B
ISO 4033, Hexagon high nuts (style 2) — Product grades A and B
ISO 4034, Hexagon regular nuts (style 1) — Product grade C
ISO 5208, Industrial valves — Pressure testing of metallic valves
ISO 5209, General purpose industrial valves — Marking
ISO 5752, Metal valves for use in flanged pipe systems — Face-to-face and centre-to-face dimensions
EN 1092-1, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories,
PN designated — Part 1: Steel flanges
EN 1515-1:1999, Flanges and their joints — Bolting — Part 1: Selection of bolting
EN 12982, Industrial valves — End-to-end and centre-to-end dimensions for butt welding end valves
ASME B1.1, Unified Inch Screw Threads, (UN and UNR Thread Form)
ASME B1.20.1, Pipe Threads, General Purpose, Inch
ASME B16.5, Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard
ASME B16.10, Face-to-Face and End-to-End Dimensions of Valves
ASME B16.34:2013, Valves Flanged, Threaded and Welding End
ASME B18.2.2, Nuts for General Applications: Machine Screw Nuts, Hex, Square, Hex Flange, and Coupling
Nuts (Inch Series)
1)
MSS-SP-55, Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping
Components — Visual Method for Evaluation of Surface Irregularities
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
DN or NPS
alphanumeric designation of size that is common for components used in a piping system, used for
reference purposes, comprising the letters DN or NPS followed by a dimensionless number indirectly
related to the physical size of the bore or outside diameter of the end connections
Note 1 to entry: The number following DN or NPS does not represent a measurable value and is not used for
calculation purposes except where specified in a product standard.
Note 2 to entry: See ISO 6708 and ASME B16.34.
1) Manufacturers Standardization Society standard.
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ISO 7121:2016(E)
3.2
PN or Class
alphanumeric designation for pressure-temperature rating that is common for components used
in a piping system, used for reference purposes, comprising the letters “PN or Class” followed by
a dimensionless number indirectly related to the pressure retaining capability as a function of
temperature of the component
Note 1 to entry: The number following PN or Class does not represent a measurable value and is not used for
calculation purposes except where specified in a product standard. There is no definitive correlation that links
PN designations to Class designations.
Note 2 to entry: See ISO 7268, EN 1333 and ASME B16.34.
3.3
service pressure/temperature rating
lesser of the shell or seat pressure/temperature rating
3.4
anti-static design
design that provides for electrical continuity between the body, ball and stem of the valve
3.5
anti-blow-out design
design that ensures the valve stem cannot be ejected from the body in the event of the gland being
removed while the valve is under pressure
4 Pressure/temperature ratings
4.1 Valve rating
The service pressure/temperature rating applicable to valves specified in this International Standard
shall be the littlest of the shell rating (4.2) or the seat rating (4.3).
4.2 Shell rating
4.2.1 The pressure/temperature ratings applicable to the valve pressure containing shell (the pressure
boundary elements, e.g. body, body cap, trunnion cap, cover, body inserts) shall be in accordance with that
specified in the pressure/temperature tables of either ASME B16.34, Standard Class, for Class designated
valves, or EN 1092-1 for PN designated valves.
4.2.2 The temperature for a corresponding shell pressure rating is the maximum temperature that is
permitted for the pressure-containing shell of the valve. In general, this maximum temperature is that
of the contained fluid. The use of a pressure rating corresponding to a temperature other than that of
the contained fluid is the responsibility of the user. For temperatures below, the lowest temperature
listed in the pressure/temperature tables (see 4.2.1), the service pressure shall be no greater than the
pressure for the lowest listed temperature. Consideration should be given to the loss of ductility and
impact strength of many materials at low temperature.
4.3 Seat and seal rating
4.3.1 Non-metallic elements, for example, seat, seals or stem seals, can impose restrictions on the
applied pressure/temperature rating. Any such restriction shall be shown on the valve identification
plate in accordance with 7.4.
4.3.2 The design shall be such that, when either polytetrafluoroethylene (PTFE) or reinforced PTFE is
used for seats, the minimum valve pressure/temperature rating shall be as specified in Table 1. Designs
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ISO 7121:2016(E)
using these seating materials having pressure/temperature ratings less than those shown in Table 1 are
not in compliance with this International Standard.
4.3.3 Seat ratings for other seat materials shall be according to the manufacturer’s standard. However,
the assigned valve service pressure/temperature rating shall not exceed that of the valve shell.
Table 1 — Minimum seat pressure/temperature rating
a a
PTFE seats Reinforced PTFE seats
c c
bar bar
b
Temperature
Floating ball Trunnion Floating ball Trunnion
°C
DN ≤ 50 50 < DN ≤ 100 DN > 100 DN > 50 DN ≤ 50 50 < DN ≤ 100 DN > 100 DN > 50
NPS ≤ 2 2 < NPS ≤ 4 NPS > 4 NPS > 2 NPS ≤ 2 2 < NPS ≤ 4 NPS > 4 NPS > 2
−29 to 38 69,0 51,0 19,7 51,0 75,9 51,0 19,7 51,0
50 63,6 47,1 18,2 47,1 70,4 47,8 18,4 47,8
75 53,3 39,2 15,2 39,2 59,9 40,4 15,6 40,4
100 43,0 31,3 12,1 31,3 49,4 33,1 12,8 33,1
125 32,7 23,3 9,1 23,3 38,9 25,8 10,0 25,8
150 22,4 15,4 6,1 15,4 28,3 18,4 7,2 18,4
175 12,1 7,5 3,0 7,5 17,8 11,1 4,4 11,1
200 — — — — 7,3 3,7 1,6 3,7
205 — — — — 5,2 2,3 1,0 2,3
For a given PN or Class designation, the assigned valve pressure/temperature ratings shall not exceed the shell ratings,
see 4.2.
a
Polytetrafluoroethylene seats.
b
Consult manufacturer for maximum design temperature rating of the valve seats.
c 5 2
1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
5 Design
5.1 Flow passageway
The flow passageway includes the circular seat opening in the ball and the body runs leading thereto. The
body runs are the intervening elements that link the seat opening to the end connection, for example, to
the thread end, weld end or socket end, or to the end-flange. Collectively, the flow passageway through
the ball bore and body runs is referred to as the flow passageway. The ball bore is categorized in this
International Standard as full bore, reduced bore and double reduced bore. The minimum effective
diameter for each category shall be such that a hypothetical cylinder having a diameter according to
Table 2 can be passed through.
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ISO 7121:2016(E)
Table 2 — Cylindrical diameter for categorizing bore size
Minimum bore diameter
mm
Nominal
Reduced Double
Nominal size
Full bore
size
bore reduced bore
NPS
DN
PN 10, 16, 25 and 40 PN 63 PN 100 PN: all PN: all
Class 150 and 300 — Class 600 Class: all Class: all
8 6 6 6 6 N/A 1/4
10 9 9 9 6 N/A 3/8
15 11 11 11 8 N/A 1/2
20 17 17 17 11 N/A 3/4
25 23 23 23 17 14 1
32 30 30 30 23 18 11/4
40 37 37 37 27 23 11/2
50 49 49 49 36 30 2
65 62 62 62 49 41 21/2
80 74 74 74 55 49 3
100 98 98 98 74 62 4
150 148 148 148 98 74 6
200 198 196 194 144 100 8
250 245 245 241 186 151 10
300 295 293 291 227 202 12
350 325 322 318 266 230 14
400 375 371 365 305 250 16
450 430 423 421 335 305 18
500 475 467 453 375 335 20
600 586 N/A N/A 487 436 24
NOTE 1 N/A: Valves having this configuration are not within the scope of this International Standard.
NOTE 2 Full bore valves meeting the minimum bore diameter in this International Standard may not meet the minimum
bore diameters of ISO 17292.
NOTE 3 For Class 900, only valves having reduced bore are within the scope of this International Standard.
5.2 Body
5.2.1 Body wall thickness
5.2.1.1 The minimum valve body wall thickness, t , shall be as specified in Table 3, except that for butt-
m
welding end valves the welding ends for connection to pipe shall be in accordance with the requirements
of Figure 1.
5.2.1.2 The minimum thickness requirements are applicable to, and are measured from, internally
wetted surfaces, i.e. up to the point where body seals are effective.
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ISO 7121:2016(E)
Table 3 — Valve body wall thickness
—
PN 10 and 16 25 and 40 63 100 — PN
a
Class 150 300 — 600 800 900 Class
Minimum valve body wall thickness, t
m
mm
Full
Nom. Nom.
bore,
size size
Double Double Double Double reduced
DN NPS
Full Reduced Full Reduced Full Reduced Full Reduced Reduced
reduced reduced reduced reduced bore,
bore bore bore bore bore bore bore bore bore
bore bore bore bore double
reduced
bore
3,3
8 2,7 2,7 N/A 2,9 2,9 N/A 2,7 2,7 N/A 3,1 3,1 N/A 3,4 1/4
3,6
10 2,9 2,9 N/A 3,0 2,9 N/A 2,9 2,9 N/A 3,4 3,3 N/A 3,8 3/8
3,9
15 3,1 3,1 N/A 3,2 3,2 N/A 3,1 3,1 N/A 3,6 3,6 N/A 4,1 1/2
5,2
20 3,4 3,4 N/A 3,7 3,7 N/A 3,5 3,5 N/A 4,1 4,1 N/A 5,8 3/4
6,0
25 3,9 3,8 3,8 4,1 4,1 4,1 4,0 4,0 4,0 4,7 4,6 4,6 6,0 1
6,4
32 4,3 4,2 4,2 4,7 4,6 4,6 4,4 4,3 4,3 5,1 5,0 5,0 6,4 11/4
5,8
40 4,7 4,5 4,5 5,2 5,0 5,0 4,8 4,7 4,7 5,5 5,4 5,4 5,8 11/2
7,0
50 5,5 5,3 5,3 6,2 5,9 5,9 5,6 5,5 5,5 6,3 6,0 6,0 7,0 2
7,9
65 5,7 5,6 5,6 6,7 6,5 6,5 6,5 6,3 6,3 6,7 6,4 6,4 7,9 21/2
N/A
80 6 5,9 5,9 7,1 6,9 6,9 7,2 7,0 7,0 7,6 7,2 7,2 9,4 3
N/A
100 6,3 6,3 6,3 7,6 7,6 7,6 8,2 7,9 7,9 9,2 8,7 8,7 11,8 4
N/A
150 7,1 6,9 6,9 9,3 8,9 8,9 10,1 9,8 9,8 12,6 11,8 11,8 16,3 6
N/A
200 7,9 7,7 7,7 10,9 10,4 10,4 12,5 12,0 12,0 15,7 14,7 14,7 20,5 8
N/A
250 8,7 8,4 8,4 12,55 12,0 12,0 14,5 13,5 13,5 18,9 17,6 17,6 24,9 10
N/A
300 9,5 9,2 9,2 14,2 13,5 13,5 16,5 15,5 15,5 22,3 20,7 20,7 29,1 12
N/A
350 10 9,6 9,6 15,2 14,4 14,4 17,8 16,8 16,8 24,1 22,5 22,5 31,8 14
N/A
400 10,8 10,4 10,4 16,8 16 16 19,8 18,6 18,6 27,3 25,4 25,4 36,0 16
N/A
450 11,7 11,1 11,1 18,7 17,3 17,3 21,7 20,4 20,4 31,1 28,9 28,9 42,0 18
N/A
500 12,4 11,9 11,9 20,2 18,8 18,8 24,0 22,5 22,5 33,2 30,8 30,8 44,3 20
N/A
600 14,3 13,3 13,3 23,7 21,8 21,8 N/A N/A N/A N/A N/A N/A N/A 24
NOTE N/A: Valves having this configuration are not within the scope of this International Standard.
a
For Class 900, only valves having reduced ball ports are within the scope of this International Standard.
5.2.1.3 Local areas having less than minimum wall thickness are acceptable, provided that all of the
following conditions are satisfied:
— the area of sub-minimum thickness can be enclosed by a circle, the diameter of which is not greater
than 03, 5 dt , where d is the minimum bore diameter given in Table 2 and t is the minimum
m
m
wall thickness given in Table 3;
— the measured thickness is not less than 0,75 t ;
m
— enclosed circles are separated from each other by an edge-to-edge distance of not less than
17, 5 dt .
m
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ISO 7121:2016(E)
5.2.1.4 The manufacturer, taking into account such factors as component bolting or thread assembly
loads, rigidity needed for component alignment, other valve design details and the specified operating
conditions is responsible for determining if a larger wall thickness is required.
Dimensions and tolerances in millimetres
a) Welding end for connection to pipe of wall thickness T ≤ 22 mm
b) Welding end for connection to pipe of wall thickness T > 22 mm
Key
A nominal outside diameter of welding end (see Table 4)
B nominal inside diameter of pipe (see Table 4 for applicable tolerance)
T nominal wall thickness of pipe
The inside and outside surfaces of valve welding ends are machine finished overall. The contour outside the envelope
formed by the end of the welding end and the dimension 1,5 T is at the option of the manuf
...
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