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.
See Table 1 for types and codes of the pipe fittings.
Table 1 Types and Codes of Pipe Fittings
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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.
GB/T 12459-2017 The following standards are cited：
