This standard specifies the type, size, and technical requirements of external threaded connection nuts for forged high-pressure valves. This standard applies to connection nuts with nominal pressure pN16.0~32.0MPa and nominal diameter DN3~200mm. JB/T 2770-1992 PN16.0～32.0MPa connection nuts JB/T2770-1992 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
PN16.0~32.0MPa Joint Nuts
Subject Content and Scope of Application
JB/T 2770-92
Replaces JB277079
This standard specifies the type, size, and technical requirements of external threaded joint nuts for forged high-pressure valves. This standard applies to joint nuts with nominal pressure PN16.0~32.0MPa and nominal diameter DN3~25mm. Cited standards
Basic dimensions of ordinary threads
GB 196
Tolerances and fits of ordinary threads
GB 197
GB6991
Technical conditions for high-quality carbon structural steel
GB1220 Stainless steel bars
JI3/T450PV16.0~32.0MPa Technical conditions for forged angle high-pressure valves, fittings and fasteners 3 Structural types and sizes
The types and sizes of joint nuts shall be as specified in Figure 1 and Table 1. Others
Marking example
Normal thread diameter 36mm, pitch 2mm joint nut; joint nut M36×2JB/T2770
Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 1992-07-20 and implemented on 1993-01·01
Nominal pressure
25.0.32.0
Nominal diameter
Technical requirementsbzxz.net
4.1 Materials
Thread code
M48×2
4.1.1 The materials of joint nuts shall be as specified in Table 2. Steel
1Cr17Ni2
JB/T2770.--92
The mechanical properties of joint nuts after heat treatment shall be as specified in Table 3. Table 3
ICr17Ni2
G31220
N·m/cm*
4.2 The basic dimensions of the thread shall comply with the provisions of GB196, and its tolerance shall comply with the provisions of GB197. 4.3 The joint nuts of steel grade 35 shall be chemically treated to prevent atmospheric corrosion. 5
Inspection rules
The magnetic particle inspection and other technical conditions of the joint nuts shall comply with the provisions of JB/T450. Additional notes:
This standard was proposed and coordinated by the Hefei General Machinery Research Institute of the Ministry of Machinery and Electronics Industry: This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Huang Mingya and Wang Xiaojun. 398
136207
269-298
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