GB/T 12221-2025 Metal valves - Face to face, end to end, centre to face and centre to end dimensions
Metal valves - Face to face, end to end, centre to face and centre to end dimensions
1 Scope
This document specifies the face to face, end to end, centre to face and centre to end dimensions and tolerances of metal valves.
This document applies to the design, production and inspection of flanged, butt-welding, and wafer-type metal valves (including gate valves, globe valves, ball valves, butterfly valves, plug valves, diaphragm valves, and check valves) with nominal sizes ranging from DN8 to DN4000 and nominal pressures from PN2.5 to PN400, or nominal sizes from NPS 1/4 to NPS 160 and pressure classes from Class 125 to Class 2500.
Note: See Annex B for the relationship between DN and NPS.
2 Normative references
No normative references are listed in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
nominal size
DN/NPS
alphanumeric designation of size for components of a pipework system, comprising the letters DN or NPS followed by a dimensionless integer number
Note 1: This dimensionless number is indirectly related to the physical size, in millimetres (mm) or inches (in), of the bore or outside diameter of the end connections.
Note 2: The dimensionless number following DN or NPS does not represent a measurable value and shall not be used for calculation purposes except where specified in a product standard.
3.2
nominal pressure
PN/Class
designation of letter-number combination related to the mechanical properties and dimensional characteristics of components of a pipework system, which comprises the letters PN or Class followed by a dimensionless number
Note 1: All equipment of the same nominal size (DN or NPS) designated by the same PN number or Class number shall have compatible mating dimensions with the flange.
Note 2: The maximum allowable pressure depends on the PN or Class, materials, element design and maximum allowable working temperature.
3.3
face-to-face and end-to-end dimensions of straight pattern valves
distance between the two planes perpendicular to the valve axis located at the extremities of the body end ports
3.4
centre-to-face and centre-to-end dimensions of angle pattern valves
distance, between the plane located at the extremity of either body end port and perpendicular to its axis and the other body end port axis
4 Structural forms and dimensions
4.1 Structural forms
4.1.1 For valves other than those with ring joint gasket sealed flanges, the face-to-face and end-to-end dimensions of straight pattern valves are shown in Figure 1, and for angle valves in Figure 2.
Key
L1- face-to-face (FTF);
L2- end-to-end (ETE).
Figure 1 Face-to-face and end-to-end dimensions of straight pattern valves
Key
L- end-to-end (ETE).
Figure 2 Centre-to-face and centre-to-end dimensions of angle pattern valves
4.1.2 The additional length of valves with ring joint facing flanges shall be in accordance with Annex C.
4.2 Face-to-face and end-to-end dimensions of flanged valves
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Structural forms and dimensions
Annex A (Informative) Comparison of clause/subclause numbers between this document and ISO 5752:2021
Annex B (Informative) Relationship between nominal dimensions DN and NPS
Annex C (Nominative) Additional length for valves with ring joint flanges
Figure 1 Face-to-face and end-to-end dimensions of straight pattern valves
Figure 2 Centre-to-face and centre-to-end dimensions of angle pattern valves
Figure 3 Tolerances for parallelism and perpendicularity
Figure C.1 Angle pattern valve with ring joint flanges
Table 1 Basic series for face-to-face and end-to-end dimensions of flanged valves (1 ~ 24)
Table 2 Basic series for face-to-face and end-to-end dimensions of flanged valves (25 ~ 71)
Table 3 Basic series for face-to-face and end-to-end dimensions of flanged valves (91 ~ 132)
Table 4 Face-to-face and end-to-end dimensions of flanged gate valves (PN series)
Table 5 Face-to-face and end-to-end dimensions for flanged gate valves (Class series)
Table 6 Face-to-face and end-to-end dimensions of flanged butterfly valves (PN series)
Table 7 Face-to-face and end-to-end dimensions of flanged butterfly valves (Class series)
Table 8 Face-to-face and end-to-end dimensions of flanged ball valves and plug valve (PN series)
Table 9 Face-to-face and end-to-end dimensions of flanged ball valves and plug valve (Class series)
Table 10 Face-to-face and end-to-end dimensions of diaphragm valves
Table 12 Face-to-face and end-to-end dimensions of flanged straight pattern globe valves (Class series)
Table 13 Face-to-face and end-to-end dimensions of flanged angle pattern globe valves and lift check valves (PN series)
Table 14 Face-to-face and end-to-end dimensions of flanged angle pattern globe valves and lift check valves (Class series)
Table 15 Face-to-face and end-to-end dimensions of flanged straight pattern check valves (PN series)
Table 16 Face-to-face and end-to-end dimensions of flanged straight pattern check valves (Class series)
Table 17 Face-to-face and end-to-end dimensions of flanged angle pattern and wafer butterfly check valves (Class series)
Table 18 Face-to-face and end-to-end dimensions of copper alloy gate valves, globe valves and check valves
Table 19 Tolerance for the face-to-face and end-to-end dimensions of flanged valves
Table 20 Tolerance for the parallelism and perpendicularity of face-to-face and end-to-end dimensions of flanged valves
Table 21 Basic series for the face-to-face and end-to-end dimensions of welded end straight pattern valves
Table 22 Basic series for the face-to-face and end-to-end dimensions of welded end angle pattern valves
Table 23 Face-to-face and end-to-end dimensions of welded end gate valves
Table 24 Face-to-face and end-to-end dimensions of welded end ball valves
Table 25 Face-to-face and end-to-end dimensions of welded end plug valves
Table 26 Face-to-face and end-to-end dimensions of welded end straight pattern globe valves, throttle valves and check valves
Table 27 Face-to-face and end-to-end dimensions of welded end globe valves, throttle valves and check valves
Table 28 Face-to-face and end-to-end dimensions of welded end valves
Table 29 Basic series for face-to-face and end-to-end dimensions of wafer valves
Table 30 Face-to-face and end-to-end dimensions of wafer butterfly valves
Table 31 Face-to-face and end-to-end dimensions of wafer butterfly type check valves (PN series)
Table 32 Face-to-face and end-to-end dimensions of butterfly type wafer check valves (Class series)
Table 33 Face-to-face and end-to-end dimensions of wafer swing check valves
Table 34 Face-to-face and end-to-end dimensions of wafer lift check valves
Table 35 Tolerance for the face-to-face and end-to-end dimensions of wafer valves
Table A.1 Comparison of clause/subclause numbers between this document and ISO 5752: 2021
Table B.1 Relation between the nominal size DN and NPS.
Table C.1 Additional length (X)
Standard
GB/T 12221-2025 Metal valves - Face to face;end to end;center to face and center to end dimensions (English Version)
Standard No.
GB/T 12221-2025
Status
to be valid
Language
English
File Format
PDF
Word Count
21000 words
Price(USD)
380.0
Implemented on
2026-5-1
Delivery
via email in 1 business day
Detail of GB/T 12221-2025
Standard No.
GB/T 12221-2025
English Name
Metal valves - Face to face;end to end;center to face and center to end dimensions
GB/T 12221-2025 Metal valves - Face to face, end to end, centre to face and centre to end dimensions
Metal valves - Face to face, end to end, centre to face and centre to end dimensions
1 Scope
This document specifies the face to face, end to end, centre to face and centre to end dimensions and tolerances of metal valves.
This document applies to the design, production and inspection of flanged, butt-welding, and wafer-type metal valves (including gate valves, globe valves, ball valves, butterfly valves, plug valves, diaphragm valves, and check valves) with nominal sizes ranging from DN8 to DN4000 and nominal pressures from PN2.5 to PN400, or nominal sizes from NPS 1/4 to NPS 160 and pressure classes from Class 125 to Class 2500.
Note: See Annex B for the relationship between DN and NPS.
2 Normative references
No normative references are listed in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
nominal size
DN/NPS
alphanumeric designation of size for components of a pipework system, comprising the letters DN or NPS followed by a dimensionless integer number
Note 1: This dimensionless number is indirectly related to the physical size, in millimetres (mm) or inches (in), of the bore or outside diameter of the end connections.
Note 2: The dimensionless number following DN or NPS does not represent a measurable value and shall not be used for calculation purposes except where specified in a product standard.
3.2
nominal pressure
PN/Class
designation of letter-number combination related to the mechanical properties and dimensional characteristics of components of a pipework system, which comprises the letters PN or Class followed by a dimensionless number
Note 1: All equipment of the same nominal size (DN or NPS) designated by the same PN number or Class number shall have compatible mating dimensions with the flange.
Note 2: The maximum allowable pressure depends on the PN or Class, materials, element design and maximum allowable working temperature.
3.3
face-to-face and end-to-end dimensions of straight pattern valves
distance between the two planes perpendicular to the valve axis located at the extremities of the body end ports
3.4
centre-to-face and centre-to-end dimensions of angle pattern valves
distance, between the plane located at the extremity of either body end port and perpendicular to its axis and the other body end port axis
4 Structural forms and dimensions
4.1 Structural forms
4.1.1 For valves other than those with ring joint gasket sealed flanges, the face-to-face and end-to-end dimensions of straight pattern valves are shown in Figure 1, and for angle valves in Figure 2.
Key
L1- face-to-face (FTF);
L2- end-to-end (ETE).
Figure 1 Face-to-face and end-to-end dimensions of straight pattern valves
Key
L- end-to-end (ETE).
Figure 2 Centre-to-face and centre-to-end dimensions of angle pattern valves
4.1.2 The additional length of valves with ring joint facing flanges shall be in accordance with Annex C.
4.2 Face-to-face and end-to-end dimensions of flanged valves
Contents of GB/T 12221-2025
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Structural forms and dimensions
Annex A (Informative) Comparison of clause/subclause numbers between this document and ISO 5752:2021
Annex B (Informative) Relationship between nominal dimensions DN and NPS
Annex C (Nominative) Additional length for valves with ring joint flanges
Figure 1 Face-to-face and end-to-end dimensions of straight pattern valves
Figure 2 Centre-to-face and centre-to-end dimensions of angle pattern valves
Figure 3 Tolerances for parallelism and perpendicularity
Figure C.1 Angle pattern valve with ring joint flanges
Table 1 Basic series for face-to-face and end-to-end dimensions of flanged valves (1 ~ 24)
Table 2 Basic series for face-to-face and end-to-end dimensions of flanged valves (25 ~ 71)
Table 3 Basic series for face-to-face and end-to-end dimensions of flanged valves (91 ~ 132)
Table 4 Face-to-face and end-to-end dimensions of flanged gate valves (PN series)
Table 5 Face-to-face and end-to-end dimensions for flanged gate valves (Class series)
Table 6 Face-to-face and end-to-end dimensions of flanged butterfly valves (PN series)
Table 7 Face-to-face and end-to-end dimensions of flanged butterfly valves (Class series)
Table 8 Face-to-face and end-to-end dimensions of flanged ball valves and plug valve (PN series)
Table 9 Face-to-face and end-to-end dimensions of flanged ball valves and plug valve (Class series)
Table 10 Face-to-face and end-to-end dimensions of diaphragm valves
Table 12 Face-to-face and end-to-end dimensions of flanged straight pattern globe valves (Class series)
Table 13 Face-to-face and end-to-end dimensions of flanged angle pattern globe valves and lift check valves (PN series)
Table 14 Face-to-face and end-to-end dimensions of flanged angle pattern globe valves and lift check valves (Class series)
Table 15 Face-to-face and end-to-end dimensions of flanged straight pattern check valves (PN series)
Table 16 Face-to-face and end-to-end dimensions of flanged straight pattern check valves (Class series)
Table 17 Face-to-face and end-to-end dimensions of flanged angle pattern and wafer butterfly check valves (Class series)
Table 18 Face-to-face and end-to-end dimensions of copper alloy gate valves, globe valves and check valves
Table 19 Tolerance for the face-to-face and end-to-end dimensions of flanged valves
Table 20 Tolerance for the parallelism and perpendicularity of face-to-face and end-to-end dimensions of flanged valves
Table 21 Basic series for the face-to-face and end-to-end dimensions of welded end straight pattern valves
Table 22 Basic series for the face-to-face and end-to-end dimensions of welded end angle pattern valves
Table 23 Face-to-face and end-to-end dimensions of welded end gate valves
Table 24 Face-to-face and end-to-end dimensions of welded end ball valves
Table 25 Face-to-face and end-to-end dimensions of welded end plug valves
Table 26 Face-to-face and end-to-end dimensions of welded end straight pattern globe valves, throttle valves and check valves
Table 27 Face-to-face and end-to-end dimensions of welded end globe valves, throttle valves and check valves
Table 28 Face-to-face and end-to-end dimensions of welded end valves
Table 29 Basic series for face-to-face and end-to-end dimensions of wafer valves
Table 30 Face-to-face and end-to-end dimensions of wafer butterfly valves
Table 31 Face-to-face and end-to-end dimensions of wafer butterfly type check valves (PN series)
Table 32 Face-to-face and end-to-end dimensions of butterfly type wafer check valves (Class series)
Table 33 Face-to-face and end-to-end dimensions of wafer swing check valves
Table 34 Face-to-face and end-to-end dimensions of wafer lift check valves
Table 35 Tolerance for the face-to-face and end-to-end dimensions of wafer valves
Table A.1 Comparison of clause/subclause numbers between this document and ISO 5752: 2021
Table B.1 Relation between the nominal size DN and NPS.
Table C.1 Additional length (X)
