JB/T 1308.21-1999 This standard is a revision of JB 1328-73 "Pg (2500kgf/cm2) elbow type, size and technical requirements". This standard specifies the elbow type, size and technical requirements for ultra-high pressure valves. This standard is applicable to elbows for neutral media such as ethylene and polyethylene with a nominal pressure of 250MPa. This standard was first published on 2011-03-1999. JB/T 1308.21-1999 PN250a elbow type, size and technical requirements JB/T1308.21-1999 standard download decompression password: www.bzxz.net

ICS23.060
Standard of the Machinery Industry of the People's Republic of China
JB/T1308.1~1308.21-1999
PN250MPa ultrahigh pressure valves and fittings
Technical conditions
Specifications for PN250MPa ultrahigh pressure valves and fittings
Published on July 12, 1999
National Bureau of Machinery Industry
Implementation on January 1, 2000
Standard of the Machinery Industry of the People's Republic of China
PN250MPa elbows
Type, dimensions and specifications of PN250MPa elbows
This standard specifies the types, dimensions and technical requirements of elbows for ultrahigh pressure valves. This standard applies to elbows for neutral media such as ethylene and polyethylene with a nominal pressure of PN250MPa. Cited Standards
JB/T1308.21-t999
Replaces JB1328-73
The clauses contained in the following standards constitute the clauses of this standard by being cited in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 8163-1987
Seamless steel pipe for conveying fluids
JB/1308.3-1999PN250MPaType, size and technical conditions of pipe ends 3 Structural type and size
3.1 The type of elbow shall be in accordance with the provisions of Figure 1.
Approved by the State Machinery Industry Bureau on July 12, 199948
Implementation on January 1, 2000
The size of the elbow shall be in accordance with the provisions of Table 1.
Nominal diameter
Technical requirements
JB/T1308.211999
Pipe specifications
35×11
50 ×16
Minimum bending radius
Outer diameter deviation and wall thickness deviation of steel pipes shall comply with the provisions of GB/T8163. 4.1
4.2The end of the bend shall comply with the provisions of JB/T1308.3. mm
Minimum straight edge length
4.3Steel pipes with positive deviations in outer diameter and wall thickness shall be used to make bends. If steel pipes that have been inspected and ground are used, the ground parts should not be placed outside the arc. bZxz.net
4.4 The pipe is hot-bent or cold-bent, and must be tempered after bending. The mechanical properties after tempering are >882MPa:
a, 2735MPa;
8.≥15%:
4.5 The ovality of the outer diameter of the bent pipe is not greater than 5%, and it is not allowed to be bent back. 5 Marking example
Bend with a nominal diameter of 15mm:
Bend DN15JB/T1308.21-1999
≥45%;
A≥68.6J
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