This standard specifies the dimensions and technical requirements of non-metallic soft gaskets for pressure vessel flanges. This standard applies to non-metallic soft gaskets for JB 4701-92 "Type A Slip-On Flange", JB 4702-92 "Type B Slip-On Flange" and JB 4703-92 "Long Neck Butt Weld Flange". JB/T 4704-2000 Non-metallic soft gaskets JB/T4704-2000 Standard download decompression password: www.bzxz.net

JB/T 4704—2000
Non-metallic gaskets
1 Scope
Industry Standard of the People's Republic of China
Non-metallic gaskets
Nonmetallic gaskets
This standard specifies the dimensions and technical requirements of non-metallic gaskets for pressure vessels. JB/T4704—2000
Replaces JB4704—1992
This standard applies to non-metallic gaskets for JB/T4701—2000 "Type A Slip-On Flange", JB/T4702-2000 "Type B Slip-On Flange" and JB/T4703-2000 "Long Neck Butt Weld Flange". 2 Referenced Standards
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 all valid. All standards are subject to revision and parties using this standard should investigate the possibility of using the most recent versions of the following standards. GB/T539—1995 Oil-resistant asbestos rubber sheet
GB/T3985—1995
GB/T 9129—1988
Marking and marking examples
Asbestos rubber sheetwww.bzxz.net
Technical conditions for asbestos rubber gaskets for steel pipe flanges Gaskets
Standard number
Nominal pressure, MPa
Nominal diameter, mm
3.2 Marking example
Non-metallic soft gaskets for nominal diameter 1000mm and nominal pressure 2.50MPa: Gasket 1000—2.50JB/T4704—2000 Structural types and dimensions
Flat sealing surface, concave-convex sealing surface, liner ring flat sealing surface and liner ring concave-convex sealing surface Non-metallic soft gaskets for flanges shall be in accordance with the provisions of Figure 1 and Table 1. 188888
State Machinery Industry Bureau
Approved on April 24, 2000
State Petroleum and Chemical Industry Bureau
138888
Implemented on September 30, 2000
Nominal pressure
PN, MPa
Nominal diameter
According to PN=1.00
According to PN=1.00
JB/T47042000
339/354
389/404
439/454
489/504| | tt | 03/410
453/460
504/510
554/560
604/610
654/660
704/710
8 04/810 | | tt | | 904/910 | 4
304/310
354/360
404/410
454/460
504/510
554/560
604/610| |tt||654/660
Note: The data within the range of the thick solid line in the table (excluding the denominator) are the soft gasket sizes for Type A flat welding flanges, and the denominator is the soft gasket size for long neck butt welding flanges.
Technical requirements
The physical properties of gasket materials shall comply with the provisions of GB/T9129. Non-metallic soft gaskets of other materials may also be selected when there is actual use experience.
5.2 The gasket material shall be the materials specified in GB/T3985 and CB/T539, and its applicable temperature and pressure range shall comply with the corresponding standards64
JB/T 4704—2000
.
The thickness limit deviation of asbestos rubber gaskets and oil-resistant asbestos rubber gaskets shall comply with the provisions of GB/T3985. 5.3
The limit deviation of gasket size shall comply with the provisions of Table 2. Nominal diameter DN
Outer diameter, mm
Inner diameter, mm
≥300~1200
>1200 ~ 3000
5The surface of the gasket shall be flat, without warping and deformation, and no lumps, bubbles, cracks, impurities or defects that may affect the use are allowed to exist. 5.5
The edges of the gaskets shall be cut neatly.
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