GB/T 17241.6-2008Integral cast iron flanges [including MODIFICATION 1] (English PDF)

Foreword

"Cast Iron Pipe Flanges" (GB/T 17241) is divided into 7 parts.

— GB/T 17241.1 Synoptic Table for Cast Iron Pipe Flanges;

— GB/T 17241.2 Cast Iron Pipe Blank Flanges;

— GB/T 17241.3 Hubbed Threaded Cast Iron Pipe Flanges;

— GB/T 27241.4 Hubbed Slip-on-welding and Hubbed Socket Welding Cast Iron

Pipe Flanges;

— GB/T 17241.5 Loose Hubbed Cast Iron Pipe Flanges for Lapped Pipe End;

— GB/T 17241.6 Integral Cast Iron Flanges;

— GB/T 17241.7 Specifications for Cast Iron Pipe Flanges.

This part adopts the relevant parts of ISO 7005-2.1988 "Metallic Flanges - Part 2.Cast

Iron Flanges" by reference. The types and dimensions of the integral cast iron flanges in

this part are consistent with those specified in ISO 7005-2.1988, but compiled in different

formats.

This part is the revision of GB/T 17241.6-1998 "Integral Cast iron Pipe Flanges" and GB/T

2503-1989 "Marine Cast Iron Pipe Flanges".

Compared with the original standard, the main changes of this standard are as follows.

— The original two standards are integrated into one; and the standard name and

compiling format are modified;

— The flange rating marks belonging to American System in the former standard are

modified, e.g. PN20 is marked as Class150, and PN50 is marked as Class300;

— Marking examples are modified.

This standard shall replace GB/T 17241.6-1998 and GB/T 2503-1989, from the

implementation date.

This part was proposed by China Machinery Industry Federation.

This part shall be under the jurisdiction of National Technical Committee on Pipe Fitting of

Standardization Administration of China.

Drafting organizations of this part. China Productivity Center for Machinery, and Zhejiang

Gaoqiangdu Fasteners Co., Ltd.

Participating drafting organizations of this part. China Technology Research & Economy

Development Institute, and Jinan Meide Casting Co., Ltd.

Chief drafting staffs of this part. Li Junying, Luo Fayuan, Ge Haiquan, Feng, and Zang

Guiming.

The previous editions replaced by this part are.

— GB/T 17241.6-1998;

— GB 2503-81 and GB/T 2503-1989.

Integral Cast Iron Flanges

1 Scope

This part of GB/T 17241 specifies the types and dimensions of the integral gray cast iron,

malleable cast iron and ductile cast iron flanges with the nominal pressure of PN2.5, PN6,

PN10, PN16, PN25, PN40, Class150, and Class300.

This part is applicable to the design, manufacture and acceptance of DN10~DN4000 gray

cast iron, malleable cast iron, and ductile cast iron integral cast iron flanges.

2 Normative References

The following standards contain provisions which, through reference in this part of GB/T

17241, constitute provisions of this part. For dated reference, the subsequent

amendments (excluding correction) or revisions of these publications do not apply.

However, the parties who enter into an agreement based on this part are encouraged to

investigate the possibility of applying the most recent editions of the standards. For

undated references, the latest edition of the normative document referred to applies.

GB/T 17241.7 Specifications for Cast Iron Pipe Flanges

3 Types and Dimensions

1 Page. 3

The thickness "c" of integral cast iron flange corresponding to the nominal dimension

of DN 500 in "Table 2 Dimensions of PN 6 Integral Cast Iron Flanges" is changed

from 20 to 30.

2 Page. 5

Table 4 Dimensions of PN 16 Integral Cast Iron Flanges

Nominal dimension DN Previous – Thread specification of bolt

Modified to be –

Thread specification of bolt

250 M20 M24

300 M20 M24

350 M20 M24

400 M24 M27

450 M24 M27

500 M24 M30

600 M27 M33

700 M27 M33

800 M30 M36

900 M30 M36

1000 M33 M39

1200 M36 M45

1400 M39 M45

1600 M45 M52

1800 M45 M52

2000 M45 M56

3 Page. 8

The diameter "L" of bolt hole corresponding to the nominal dimension of

NPS24/DN600 in "Table 7 Dimensions of Class150 (PN20) Integral Cast Iron

Flanges" is modified from 32.5 to 35.5.

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