JB/T 1308.14-1999 This standard is a revision of JB 1321-73 "Pg (2500kgf/cm2) stud types, dimensions and technical requirements". This standard specifies the types, dimensions and technical requirements of studs for ultra-high pressure valves. This standard is applicable to studs for neutral media such as ethylene and polyethylene with a nominal pressure of 250MPa. This standard was first published on 2010-03-17. JB/T 1308.14-1999 PN250a stud types, dimensions and technical requirements JB/T1308.14-1999 Standard download decompression password: www.bzxz.net

ICS23.060
Machinery Industry Standard of the People's Republic of China
JB/T1308.1~1308.21-1999
PN250MPa ultra-high pressure valves and fittings
Technical conditions
Specifications for PN250MPa ultra-high pressure valves and fittings
Published on July 12, 1999
State Machinery Industry Bureau
Implementation on January 1, 2000
Machinery Industry Standard of the People's Republic of China
PN250MPa double-ended studs
Type, dimensions and specifications of PN250MPa stud bolts
This standard specifies the type, dimensions and technical requirements of double-ended operating columns for ultra-high pressure valves. JB/T1308.14—1999
Recommended JB132173
This standard applies to studs for neutral media such as ethylene and polyethylene with a nominal pressure of PN250MPa. 2 Cited standardsbZxz.net
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T90—1985
GB/T 196—1981
GB/T 197--1981
GB/T 224—1987
GB/T 1804-1992
GB/T 3077—1988
JB/T1308.2—1999
Structural type and size
Fastener acceptance inspection, marking and packaging
Basic size of common thread (diameter 1-600mm)Tolerance and fit of common thread (diameter 1~355mm)Determination method of decarburization depth of steel
General toleranceUnindicated tolerance of linear dimension
Technical conditions of alloy structural steel
PN250MPaTechnical conditions of valves, pipe fittings and purple fasteners3.1The type of stud bolts shall be in accordance with the provisions of Figure 1. Figure 1
3.2The dimensions of stud bolts shall be in accordance with the provisions of Table 1 and Table 2. Approved by the State Bureau of Machinery Industry on July 12, 1999, and implemented on January 1, 2000. Nominal size JB/T 1308.14—1999 Weight per 1000 pieces Technical requirements JB/T1308.14—1999 4.1 Material of stud is 42CrMo, and the technical requirements are in accordance with the provisions of GB/T3077. 4.2 Mechanical properties after heat treatment are in accordance with the provisions of Table 3. Table 3 Material grade 42CrMo Tensile strength. , Service points. 、
Elongation 8，
Impact value A
4.3The basic dimensions of the thread shall comply with the provisions of GB/T196, and the tolerance shall comply with the second-grade accuracy specified in GB/T197. Hardness
269-321
4.4Diameter 4, for turning. If rolling is used, d, should be within the range of the thread diameter, and the specific size shall be determined by the manufacturer. r is only applicable to turning studs.
4.5 When the studs are directly rolled with cold-drawn polished materials: before rolling the threads, two studs with the same diameter made of polished materials with the same steel grade, the same diameter and heat-treated under the same process conditions shall be sampled and inspected for decarburization layer according to the provisions of GB/T224. The thickness of the total decarburization layer shall not exceed 1.5% of the diameter and shall not exceed 0.3mm (if the process can maintain the above specified values, decarburization layer inspection is not required) 4.6 Studs shall be inspected according to the provisions of "Magnetic Particle Inspection Method for High-Pressure Fasteners". There shall be no cracks or other defects that affect the strength. Studs shall be chemically treated to prevent atmospheric corrosion. 4.73
4.8 Other technical requirements shall be in accordance with the provisions of JB/T1308.2. 4.9 Acceptance rules, packaging and marking shall be in accordance with the provisions of GB/T90. 5
Marking example
Coarse-pitch ordinary screw, double-ended stud with a diameter of 27mm and a length of 180mm: double-ended stud M27×180JB/T1308.14199931
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