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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard partially replaces GB/T 12459-2005 Steel Butt-welding Seamless Pipe Fittings and GB/T 13401-2005 Steel Plate Butt-welding Pipe Fittings. The following technical changes have been made with respect to GB/T 12459-2005 (the previous edition):
——Contents concerning types and codes, dimensions and tolerances, pressure ratings, test and marking in GB/T 12459-2005 and GB/T 13401-2005 are combined in this standard; seamless pipe fittings and steel plate welding pipe fittings are no longer distinguished for various specifications of pipe fittings in this standard;
——Contents concerning raw materials, manufacturing and inspection in GB/T 12459-2005 are deleted, which are combined in GB/T 13401-2017 Steel Buttwelding Pipe Fittings - Technical Specification;
——Pressure design requirements and descriptions of pipe fittings are added;
——Relevant information about design and calculation of pipe fittings is added;
——Calculation and description of relevant parameters of the elbow with bending radius of R=3D and the elbow with special angle;
——Contents concerning design verification tests of pipe fittings are modified;
——Dimensional range is expanded.
This standard was proposed by China Machinery Industry Federation.
This standard is under the jurisdiction of the National Technical Committee on Pipe Fittings of Standardization Administration of China (SAC/TC 237).
The previous editions of the standards replaced by this standard are as follows:
——GB/T 12459-1990 and GB/T 12459-2005;
——GB/T 13401-1992 and GB/T 13401-2005.
Steel Buttwelding Pipe Fittings - Types and Parameter
1 Scope
This standard specifies types and codes, pressure design, dimensions, surface outlines, end bevels, tolerances, marking and product quality certificate of DN 15 ~ DN 1500 (NPS1/2~NPS60) steel buttwelding pipe fittings (hereinafter referred to as "pipe fittings").
This standard is applicable to steel buttwelding seamless and welding pipe fittings.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 9118 Loose Hubbed Steel Pipe Flanges with Welding Neck Collar
GB/T 9124 Specification for Steel Pipe Flanges
GB/T 13401-2017 Steel Buttwelding Pipe Fittings - Technical Specification
3 Types and Codes
See Table 1 for types and codes of the pipe fittings.
Table 1 Types and Codes of Pipe Fittings
Category Type Code
Seamless pipe fittings Welding pipe fittings
45° elbow Long radius 45EL W45EL
3D radius 45E3D W45E3D
90° elbow Long radius 90EL W90EL
Long radius reducing 90ELR W90ELR
Short radius 90ES W90ES
3D radius 90E3D W90E3D
180° elbow Long radius 180EL W180EL
Short radius 180ES W180ES
Reducer Concentric RC WRC
Eccentric RE WRE
Tee Straight TS WTS
Reducing TR WTR
Cross Straight CRS WCRS
Reducing CRR WCRR
Pipe cap — C WC
Lap joint stub end Long LJL WLJL
Short LJS WLJS
Note: the elbow with special angle may be represented in angle value + corresponding letter code of product type.
4 Pressure Design of Pipe Fittings
4.1 Pressure ratings
Permissible pressure ratings of the pipe fittings designed and manufactured according to this standard may be calculated according to their connected seamless straight pipes with the same specifications, materials and wall thicknesses. The nominal dimensions (or outside diameters at bevel), material grades, wall thicknesses (or schedule number) marked on the pipe fittings represent the pressure ratings.
4.2 Design of pipe fittings
4.2.1 The pipe fittings shall be designed with the same internal pressure endurance capability as their connected seamless straight pipes with the same specifications, materials and wall thicknesses.
4.2.2 Pipe fittings produced according to this standard shall be designed according to the following methods:
a) Carrying out confirmatory pressure test according to the requirements of Annex A and determine wall thicknesses of pipe fittings thereby. Where necessary, corresponding confirmatory pressure test report and record shall be provided for confirmation.
b) As required by the user, the finished pipe fittings shall meet the requirements of the minimum wall thickness given in Annex B, and shall be indicated with GB/T 12459-B in contracts or product markings.
c) As required by the user, the finished pipe fittings shall be designed according to the mathematical analysis method or other stress analysis method given in corresponding pressure piping codes, and shall be indicated with GB/T 12459-C in contracts or product markings. In order to meet this requirement, pipe fitting manufacturers shall provide design drawings and calculation sheets for the approval of the purchaser.
4.2.3 The manufactory shall be able to obtain the report on mathematical analysis, basic design calculation or successful fluid blasting verification results for inspection of the purchaser.
5 Dimensions of Pipe Fittings
5.1 Normal dimensions
5.1.1 Nominal dimensions of pipe fittings are represented in DN or NPS. See the Column "nominal dimension" in tables for dimensions of pipe fittings for their relationship.
5.1.2 For the purpose of this standard, the outside diameters at bevel of pipe fittings are divided into I and II series. Series I is a general series and thus recommended, while Series II is a special series.
5.1.3 See Figure 1 and Table 2 for dimensions of 90° and 45° long radius elbows, see Figure 2 and Table 3 for dimensions of 90° reducing long radius elbows, see Figure 3 and Table 4 for dimensions of 180° long radius elbows, see Figure 4 and Table 5 for dimensions of 90° long radius elbows, see Figure 5 and Table 6 for dimensions of 180° short radius elbows, see Figure 6 and Table 7 for dimensions of 90°and 45° 3D radius elbows, see Figure 7 and Table 8 for dimensions of straight tees and crosses, see Figure 8 and Table 9 for dimensions of reducing tees and crosses, see Figure 9 and Table 10 for dimensions of lap joint stub ends, see Figure 10 and Table 11 for dimensions of pipe caps and see Figure 11 and Table 12 for dimensions of reducers.
Foreword i
1 Scope
2 Normative References
3 Types and Codes
4 Pressure Design of Pipe Fittings
5 Dimensions of Pipe Fittings
6 Surface Outlines
7 End Bevels
8 Tolerances
9 Marking
10 Product Quality Certificate
Annex A (Normative) Design Verification Test
Annex B (Informative) Design and Calculation of Pipe Fittings