This standard specifies the structural type, technical requirements, test methods, marking and supply of flanged and butt-welded steel pipeline ball valves. JB/T 7745-1995 Pipeline ball valve JB/T7745-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Pipeline Ball Valve
1 Subject Content and Scope of Application
JB/T 7745--95
This standard specifies the structural type, technical requirements, test methods, marking and supply of welded and butt-welded steel pipeline ball valves (referred to as ball valves).
This standard is applicable to ball valves for pipelines and equipment with a nominal pressure of PV1.610.0MPa and a nominal diameter of I)N50~1000mm. 2 Reference Standards
GB 150
GB 197
GB 901
GB1220
Steel pressure vessels
Ordinary thread basic size (diameter 1~600mm) Ordinary thread tolerance and fit (diameter 1355mm) Equal length studs Grade B
Stainless steel bars
G13 6175
Type 2 hexagonal nuts Grade A and B
G19113.1~9113.26 Integral steel pipe legal rights GB12220
GB 1222
GB12224
GB 12228
GB12229
GB12230
GB12237
General valves
Flange-connected metal valves! Structural length
Steel valves
General requirements
Technical conditions for carbon steel forgings
General valves
Technical conditions for carbon steel castings for general valves
Road valves
Technical conditions for Austrian steel castings
General valve flanges and butt-welding steel ball valves G3/T 12252
Supply requirements for general valves
G3/T 13402
Large diameter carbon steel pipe flanges
Fire resistance test for valves
J3/T 6899
Testing and inspection of valves
213J16 006
3 Terms
3.1 Double seal structure
It has two independent sealing pairs and a soft seal valve seal with natural pressure relief. 3.2 Valve stem anti-drop structure
It can ensure that the abnormal rise of the inner surface of the ball valve does not cause the valve to drop, and can ensure that the leakage is reduced after the packing is burned. 4 Structural type
The given configuration type and main parts of the floating ball valve and the fixed ball valve are shown in Figure 1, Figure 2 and Figure 3. Approved by the Ministry of Machinery Industry of the People's Republic of China on June 20, 1995 475
1996-01~01 Implementation
JB/T7745---95
Body: 2 Ball: 3 Sealing ring: 4 Stem: 5:-Packing gland..
Figure 1N200
1. Body: 2 Ball: 3 Sealing ring; 1·Valve stem; 5·Packing gland
Figure 2 200DN600
Body: 2·Ball: 3
·Sealing ring··Valve stem packing gland
Figure 3 DN600
5 Technical requirements
5.1 Pressure-temperature rating
JB/T 7745- -95
The pressure-temperature rating of ball valves shall comply with the provisions of GB12224. 5.2 Valve body
5.2.1 The valve body can be integral or modular. The strength of the joint of the modular valve body shall not be lower than the strength of the end flange connection or the weld strength of the butt-weld connection.
5.2.2 The minimum wall thickness of the valve body shall be in accordance with the provisions of Table 1. Table 1
Nominal diameter DN
Minimum wall thickness of the shell
Force, MPa
5.2.3 The structural length of the flange connection and butt-weld connection of the ball valve shall be in accordance with the provisions of Table 2. 472
.t2.（）
Nominal diameter
PN1. 6.PN2- 0
Flange end
Welding end
Note: The length of the space structure shall be in accordance with the provisions of GB12221: JB/T 7745-95wwW.bzxz.Net
Table 2 Structural length
EN2.5.PN4.O,PN5.0
Flange end
Welding end
Flange end
Welding end
? 337
5.2.4 Method of connection The valve body is integrally cast or forged, and can also be welded. The method of welding connection should be butt welding. Welding 1 should be qualified according to the relevant specifications, and the welding requirements should comply with the provisions of GB150. 5.2.5 The type and size of the connecting flange shall comply with the provisions of GB9113.1~9113.26. For flanges not specified in GB9113.19113.26, they shall comply with the provisions of GB/13402 or the provisions of the order contract. 5.2.6 The size of the butt welding connection groove shall comply with the provisions of GB12224 or the provisions of the order contract. 5.2.7 The valve body channel shall be circular, and its minimum diameter shall comply with the provisions of Table 3. The diameter of the contraction ball valve is represented by two digits. The first digit represents the nominal size of the end, and it determines the structural length of the ball valve: the first digit is the minimum opening and closing diameter listed in Table 3, and it is the corresponding nominal diameter of the ball valve.
IB/T7745
Minimum value of valve body channel
Minimum straightness of valve body channel
As specified in the order contract, the valve body can be provided with a bleed hole, the position of which is shown in Figure 1, and the thread size of the bleed hole shall comply with the provisions of GB12224. 5.2.8
Floating ball
Position of bleed hole
Fixed ball
5.2.9If the combined valve body is connected by flange, the connecting studs can be equal-length double-headed screws. According to the provisions of GB901, full-thread studs can also be used; nuts shall comply with the provisions of GB6175; studs less than and equal to M24 shall adopt coarse-thread ordinary threads , when the maximum M24, the pitch is not more than 3mm, the thread size and tolerance shall be in accordance with the provisions of (B196 and GB197. 5.3 The minimum diameter of the ball channel shall be in accordance with the provisions of Table 3 or the requirements of the order contract. The rest shall be in accordance with the provisions of GB12237. 5.4 The valve stem shall be designed with an anti-slip structure. The rest shall be in accordance with the provisions of GB12237. 5.5 In addition to the provisions of GI312237, the soft sealing valve seat shall be designed with a double sealing structure to ensure complete sealing under high pressure, low positive and true tight conditions.
5.6 Anti-static requirements shall be in accordance with the provisions of GB12237. 5.7 Fire-resistant structure
JB/7745--95
If the order contract stipulates, the ball valve is designed with a resistant structure that complies with the provisions of J3/T6899. 5.8 Operation In addition to the provisions of GB12237, the ball valve should be designed with a locking hole in the field or where there is a lot of vibration to prevent the danger of accidental impact.
5.9 Materials
5.9.1 The valve body material shall comply with the provisions of GB12229, GB12228 or (GB12230. 5.9.2 The corrosion resistance of the ball and valve cup materials shall not be lower than that of the valve body material. The ball shall comply with the provisions of GB12229. GB131223 or (313122. The valve stem shall comply with the provisions of GB1220, etc. 5 .9.3 Valve seats, sealing rings, packings, gaskets, ) rings, wrenches, valve body drain plugs shall comply with the provisions of (1312237: 5.9.4 The connecting studs shall be alloy steel, except for those specified in the training contract that the ball valve is used with a leakage of less than -30 (or more than 482 (or other materials are used to increase the corrosion resistance to the environment); the nut material shall be high-quality carbon steel. 6 Test methods
6.1 Test and inspection of ball valves shall comply with the provisions of 7B16006 6.2 Ball valves with anti-static structures shall be subject to anti-static tests in accordance with the requirements of G1312237: 6.3 Ball valves with fire-resistant structures shall be subject to fire-resistant tests in accordance with the provisions of J13/T6899 7 Marking
The marking of ball valves shall be in accordance with the provisions of (G1312220. 8 Supply
The ball valves shall be shipped in accordance with the provisions of (113/T12252 Additional Notes:
This standard is proposed by the National Valve Standardization Technical Committee. The standard was issued by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry, and this standard was drafted by Zigong High Pressure Valve. The main drafters of this standard are Hao Chonggao, Teng Yaohun, Ni Luran, and Zhang Yuanxiao. 17
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