JB/T 7768-1995 Safety Technical Requirements for Seals JB/T7768-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7768-95
Safety Technical Conditions for Seals
Published on June 16, 1995
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1996
Mechanical Industry Standard of the People's Republic of China
Safety Technical Conditions for Seals
1 Subject Content and Scope of Application
JB/T7768-95
This standard specifies the technical requirements for the safe use of sealing gaskets for pipe flanges (hereinafter referred to as gaskets) and sealing packings for valves (hereinafter referred to as packings).
This standard applies to the technical inspection of gaskets and packings during the manufacturing and use process. 2 Reference standards
GB3986
GB9129
GB9130
GB/T13404
JB/T6369
JB/T6617
JB/T6618
JB/T6622
JB/T6623
JB/T6626
JB/T6627
JB/T6628
J B/T7370
JB/T7760
JB/T7852
3 General
Test method for loss on ignition of asbestos rubber sheet
Spiral wound gaskets for steel pipe flangesDimension seriesTechnical conditions for spiral wound gaskets
Analysis method for boiler water and cooling water, determination of chlorideMercury salt titrationAsbestos rubber gaskets for flat steel pipe flangesAsbestos rubber gaskets for convex steel pipe flangesAsbestos rubber gaskets for concave and convex steel pipe flangesRod-groove steel pipe Asbestos rubber gaskets for flangesOctagonal metal ring gaskets for steel pipe flange connectionsOval metal ring gaskets for steel pipe flange connectionsTechnical conditions for asbestos rubber gaskets for steel pipe flangesTechnical conditions for metal ring gaskets for steel pipe flange connectionsPolytetrafluoroethylene coated gaskets for pipe flanges
Technical conditions for flexible graphite metal spiral wound gasketsTechnical conditions for flexible graphite packing rings for valvesTechnical conditions for polytetrafluoroethylene raw tape for metal spiral wound gasketsDetermination method for chlorine content in flexible graphite plates
Determination method for sulfur content in flexible graphite plates
t||PTFE braided packing
Carbon (chemical) fiber impregnated PTFE braided packing Flexible graphite composite reinforced (plate) pad
Flexible graphite braided packing
Valve packing sealing test specification
Technical conditions for polyacrylonitrile pre-oxidized fiber for braided packing In order to ensure the product performance and quality of gaskets and packings, to ensure the safe operation of mechanical equipment under high temperature, high pressure, flammable, explosive, corrosive, toxic and other working conditions, and to protect the safety of people's lives and property, this technical condition is specially formulated. Approved by the Ministry of Machinery Industry on June 16, 1995
Implemented on July 1, 1996
4 Safety technical requirements for gaskets
4.1 Materials
JB/T7768-95
4.1.1 The sulfur content of flexible graphite for gaskets should not be greater than 1500ppm, and should not be greater than 1000ppm for special requirements, and the oxygen content should not be greater than 100ppm.
The performance index of polytetrafluoroethylene raw tape for spiral wound gaskets shall comply with the provisions of Chapter 3 of JB/T6618. The ignition loss of asbestos tape for spiral wound gaskets shall not exceed 25%, and the fluorine content shall not exceed 100ppm. 4.1.3
The performance index of metal tape for spiral wound gaskets shall comply with the provisions of Article 3.1 of GB4622.3. The performance index of materials for polytetrafluoroethylene coated gaskets shall comply with the provisions of Article 5.1 of GB/T13404. The performance index of materials for metal ring gaskets shall comply with the provisions of Chapter 1 of GB9130. Dimensions
The dimensions of spiral wound gaskets shall comply with the provisions of GB4622.2 or user requirements. The dimensions of polytetrafluoroethylene coated gaskets shall comply with the provisions of Article 3.2 of GB/T13404 or user requirements. The dimensions of composite reinforced gaskets and asbestos rubber gaskets shall comply with the provisions of GB9126.1~9126.4 or user requirements. The size of the metal ring gasket shall comply with the provisions of GB9128.1, GB9128.2 or user requirements. Performance indicators
The performance indicators of flexible graphite metal spiral wound gaskets shall comply with the provisions of Articles 3.2 to 3.4 of JB/T6369. The performance indicators of polytetrafluoroethylene metal spiral wound gaskets and asbestos metal spiral wound gaskets shall comply with the provisions of Chapter 7 of GB4622.3. The performance indicators of polytetrafluoroethylene coated gaskets shall comply with the provisions of Articles 5.2 and 5.3 of GB/T13404. The performance indicators of flexible graphite composite reinforced gaskets shall comply with the provisions of Article 5.1 of JB/T6628. The performance indicators of metal ring gaskets shall comply with the provisions of Chapters 2 to 4 of GB9130. The performance indicators of asbestos rubber gaskets shall comply with the provisions of Chapters 1 to 4 of GB9129. Conditions of use
The operating temperature of the gasket shall comply with the provisions of Table 1. Table 1
Types of gaskets
Spiral wound gasket
Covered gasket
Composite reinforced gasket
Metal ring gasket
Asbestos rubber gasket
Gasket material
Metal/flexible graphite
Metal/asbestos
Metal/polyvinyl fluoride
PTFE coated asbestos
Flexible graphite/low carbon steel
Flexible graphite/oCr19Ni9
Soft iron, 01, 08, 00Cr17Ni14Mo2
OCr19Ni9
Asbestos rubber sheet
The operating pressure of the gasket shall comply with the provisions of Table 2. Maximum operating temperature
Gasket type
Maximum operating pressure
Spiral wound gasket
JB/T7768-95
Coated gasket
Verification test is required when used under high temperature and high pressure at the same time. 4.4.3
4.5 Inspection method
Composite reinforced gasket
Metal ring
Asbestos rubber gasket
The determination of chlorine content of flexible graphite shall be carried out in accordance with the provisions of JB/T6622, and the determination of sulfur content shall be carried out in accordance with the provisions of JB/T.6623. The inspection of technical indicators of polytetrafluoroethylene raw tape shall be carried out in accordance with the provisions of Chapter 4 of JB/T6618. The determination of asbestos ignition loss shall be carried out in accordance with the provisions of GB3986, and the determination of chlorine content shall be carried out in accordance with the provisions of GB6905.3. The performance index of spiral wound gaskets shall be tested in accordance with the provisions of Chapter 8 of GB4622.3, and the performance index of polytetrafluoroethylene coated gaskets shall be tested in accordance with the provisions of GB/T13404. The performance index of asbestos rubber gaskets shall be tested in accordance with the provisions of GB9129. The performance index of flexible graphite composite reinforced gaskets shall be tested in accordance with the provisions of Chapter 6 of JB/T6628. Packing safety technical requirements
5.1 Materials
The performance index of flexible graphite plates for packing rings shall comply with the provisions of Articles 3.1 and 3.2 of JB/T6617. 5.1.1
The chlorine content of flexible graphite for braided packing shall not exceed 50ppm. The performance index of polypropylene bladder pre-oxidized fibers for braided packing shall comply with the provisions of JB/T7852. Performance index
The performance index of flexible graphite packing rings shall comply with the provisions of Articles 3.2 to 3.4 of JB/T6617. The performance index of flexible graphite braided packing shall comply with the provisions of Chapter 5 of JB/T7370. The performance index of carbon (chemical) fiber braided packing shall comply with the provisions of Chapter 5 of JB/T6627. The performance index of polytetrafluoroethylene braided packing shall comply with the provisions of Chapter 4 of JB/T6626. The test life of packing under the use pressure and use temperature shall be not less than 6000 times. Use conditions
The use pressure and use temperature of packing shall comply with the provisions of Table 3. Table 3
Packing type
Molded packing
Braided packing
Flexible graphite
Flexible graphite/metal
Flexible graphite/resin
Filled polytetrafluoroethylene
Flexible graphite/metalbzxZ.net
Flexible graphite/non-metal
Carbon fiber
Carbon fiber type I
Carbon fiber type I
Polytetrafluoroethylene
Maximum working pressure
Maximum working temperature
JB/T7768-95
5.4 Inspection method
5.4.1 The inspection of performance indicators of flexible graphite packing rings and flexible graphite used for packing rings shall be carried out in accordance with the provisions of Chapter 4 of JB/T6617. 5.4.2 The inspection of the performance index of flexible graphite braided packing shall be carried out in accordance with the provisions of Chapter 6 of JB/T7370, and the determination of the chlorine content of flexible graphite used for packing shall be carried out in accordance with the provisions of JB/T6622. 5.4.3 The performance index of carbon fiber braided packing shall be tested in accordance with the provisions of Chapter 6 of JB/T6627, and the performance index of polyacrylonitrile pre-oxidized fiber used as packing shall be tested in accordance with the provisions of Chapter 4 of JB/T7852. 5.4.4 The performance index of polytetrafluoroethylene braided packing shall be tested in accordance with the provisions of Chapter 5 of JB/T6626. 5.4.5 The life test of sealing packing shall be carried out in accordance with the provisions of JB/T7760. Additional remarks:
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Liu Guoshan, Zhang Weiren and Wu Suyun. People's Republic of China
Mechanical Industry Standard
Safety Technical Conditions for Sealing Parts
JB/T7768-95
Published by the Machinery Standardization Research Institute of the Ministry of Machinery Industry, Machinery Standardization Research Institute, Printing Box, Postal Code 100081)
(P.O. Box 8144, Beijing
Copyright reserved
Reproduction is prohibited
Format 880×12301/16
Word count 8,000
Sheet 1/2
First printing in April 1996
First edition in April 1996
Printing number 00,001
No. 95-146
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