Material of Rubber Seals Used for Gas Supply Pipes and Fittings
This standard is equivalent adoption of international standard ISO 6447-1983 Rubber Seals - Joint Rings Used for Gas Supply Pipes and Fittings - Specification for Material.
1 Subject Content and Application Scope
This standard specifies property requirement and test method for material of rubber seals used for gas (natural gas or artificial gas) supply pipes and fittings at operating temperatures below 50℃ as well as some general requirements for finished seals.
This standard is applicable to cast iron, steel, copper and plastic pipeline seals.
This standard is not applicable to seals made of foam rubber or those containing closed-pore spatial structure.
2 Normative References
GB 528 Rubber, Vulcanized - Determination of Tensile Stress - Strain Properties
GB 531 Shore A Hardness Test Method of Vulcanized Rubber
GB 1682 Rubber, Vulcanized - Test Method of Brittleness Temperature
GB 1683 Determination of Compression Set under Constant for Vulcanized Rubber
GB 1685 Rubber Vulcanized - Determination of Stress Relaxation in Compression at Normal and Elevated Temperature
GB 1690 Rubber, Vulcanized - Determination of the Effect of Liquids
GB 2941 Rubber - Standard Temperature, Humidity and Time for the Conditioning Environmental and Testing of Test Pieces
GB 3452.2 Appearance Quality Acceptance Criteria for Rubber O-rings
GB 3512 Rubber Vulcanized - Accelerated Ageing or Heat-resistance Test - Air-oven Method
GB 3672 Rubber - Dimensional Tolerances of Solid Moulded and Extruded Products
GB 5721 General Rules of Identification, Packaging and Transportation for Rubber Sealing Products
GB 5722 General Rules of Storage for Rubber Sealing Products
GB 5723 Rubber, Vulcanized - General Rules of Measuring Dimension of Test Pieces and Products for Test Purposes
GB 6031 Rubber, Vulcanized - Determination of International Hardness (30~85IRHD)- Normal Test Method
GB 6032 Rubber, Vulcanized - Determination of International Hardness (30~85IRHD)- Micro Test Method
GB 7529 General Rules of Visual Quality for Moulded and Extruded Rubber Products
3 Classification
Five classes of materials and products are specified according to hardness, and correspond to preferred nominal hardness of 50, 60, 70, 80 and 88IRHD.
4 Technical Requirements
4.1 Materials and technology
4.1.1 Raw materials used for manufacturing rubber shall meet the requirements of relevant technical specifications.
4.1.2 The materials shall be free of any substance which may have a deleterious effect on the conveyed gas, or on the property of the pipeline and fittings as well as the seals.
4.1.3 Processing technology of the materials shall meet the requirements of relevant technical specifications, and the materials shall be free from visible rubber lump and impurities with size larger than 0.2mm.
4.2 Property requirements
For vulcanized rubber used for manufacturing seal or seal products, physical property shall meet the requirements of the following table.
4.3 General requirements for seal products
Property Requirements for Rubber Seal Material
Property Unit Requirements
50 60 70 80 88
Hardness IRHD 46~55 56~65 66~75 76~84 85~91
Tensile strength, minimum Mpa 9 10 10 10 10
Elongation at break, minimum % 400 300 200 1501) 1001)
Compression set:
After 70h at standard ambient temperature, maximum % 10 10 10 151) 151)
After 22h at 70℃, maximum % 20 20 20 201) 201)
After 7d of aging in the air at 70℃:
Hardness change, maximum IRHD ±6 ±6 ±6 ±6 ±6
Tensile strength change, maximum % -15 -15 -15 -15 -15
Change in elongation at break, maximum % -25~+10 -25~+10 -25~+10 -30~+10 -40~+10
Stress relaxation in compression:
After 7d at standard ambient temperature, maximum % 15 15 15 151) 151)
After 90d at standard ambient temperature, maximum2) % 22 22 22 221) 221)
Liquid B immersion
After 7d at standard ambient temperature:
Hardness change, maximum IRHD -16 -15 -15 -14 -12
Volume change, maximum % +30 +30 +30 +30 +30
After 7d of soaking and 4d of drying in the air at 70℃:
Change in volume 2) % -15 -12 -10 -10 -10
Low temperature brittleness 2) No test pieces shall break
Temperature of test: -15℃, -25℃ or -40℃ depending on the conditions of service or transportation of the seals:
Notes:
1) The requirements for materials of preferred nominal hardness 80 or 88 IRHD shall apply only when the material is directly participating in the sealing function.
2) It is optional test, and it is required only for qualification test or when it is explicitly emphasized by the user.
4.3.1 Process quality
Processing technology of seals shall meet the requirements of relevant technical specification, seal products shall be free from pores, breaches and other defects affecting their use functions.
4.3.2 Dimensions and Tolerances
Dimensions and tolerances shall be the subject of agreement between the interested parties, and shall be chosen from the appropriate classes in GB 3672.
4.3.3 Marking, packaging, transportation and storage
If dimensions permit, seals or packing materials shall be provided with the letter "G" to indicate the use of the ring. Marking, packaging and transportation shall meet the requirements of GB 5721. The seals shall be stored according to the requirements of GB 5722.
5 Test Method
5.1 Appearance inspection
Appearance of rubber material is subject to visual inspection, appearance inspection of seal products shall be conducted according to GB 3452.2 and GB 7529. Dimensions of finished products shall be determined according to GB 5723.
1 Subject Content and Application Scope
2 Normative References
3 Classification
4 Technical Requirements
5 Test Method
6 Inspection Rules
7 Marking, Packaging, Transportation and Storage
Material of Rubber Seals Used for Gas Supply Pipes and Fittings
This standard is equivalent adoption of international standard ISO 6447-1983 Rubber Seals - Joint Rings Used for Gas Supply Pipes and Fittings - Specification for Material.
1 Subject Content and Application Scope
This standard specifies property requirement and test method for material of rubber seals used for gas (natural gas or artificial gas) supply pipes and fittings at operating temperatures below 50℃ as well as some general requirements for finished seals.
This standard is applicable to cast iron, steel, copper and plastic pipeline seals.
This standard is not applicable to seals made of foam rubber or those containing closed-pore spatial structure.
2 Normative References
GB 528 Rubber, Vulcanized - Determination of Tensile Stress - Strain Properties
GB 531 Shore A Hardness Test Method of Vulcanized Rubber
GB 1682 Rubber, Vulcanized - Test Method of Brittleness Temperature
GB 1683 Determination of Compression Set under Constant for Vulcanized Rubber
GB 1685 Rubber Vulcanized - Determination of Stress Relaxation in Compression at Normal and Elevated Temperature
GB 1690 Rubber, Vulcanized - Determination of the Effect of Liquids
GB 2941 Rubber - Standard Temperature, Humidity and Time for the Conditioning Environmental and Testing of Test Pieces
GB 3452.2 Appearance Quality Acceptance Criteria for Rubber O-rings
GB 3512 Rubber Vulcanized - Accelerated Ageing or Heat-resistance Test - Air-oven Method
GB 3672 Rubber - Dimensional Tolerances of Solid Moulded and Extruded Products
GB 5721 General Rules of Identification, Packaging and Transportation for Rubber Sealing Products
GB 5722 General Rules of Storage for Rubber Sealing Products
GB 5723 Rubber, Vulcanized - General Rules of Measuring Dimension of Test Pieces and Products for Test Purposes
GB 6031 Rubber, Vulcanized - Determination of International Hardness (30~85IRHD)- Normal Test Method
GB 6032 Rubber, Vulcanized - Determination of International Hardness (30~85IRHD)- Micro Test Method
GB 7529 General Rules of Visual Quality for Moulded and Extruded Rubber Products
3 Classification
Five classes of materials and products are specified according to hardness, and correspond to preferred nominal hardness of 50, 60, 70, 80 and 88IRHD.
4 Technical Requirements
4.1 Materials and technology
4.1.1 Raw materials used for manufacturing rubber shall meet the requirements of relevant technical specifications.
4.1.2 The materials shall be free of any substance which may have a deleterious effect on the conveyed gas, or on the property of the pipeline and fittings as well as the seals.
4.1.3 Processing technology of the materials shall meet the requirements of relevant technical specifications, and the materials shall be free from visible rubber lump and impurities with size larger than 0.2mm.
4.2 Property requirements
For vulcanized rubber used for manufacturing seal or seal products, physical property shall meet the requirements of the following table.
4.3 General requirements for seal products
Property Requirements for Rubber Seal Material
Property Unit Requirements
50 60 70 80 88
Hardness IRHD 46~55 56~65 66~75 76~84 85~91
Tensile strength, minimum Mpa 9 10 10 10 10
Elongation at break, minimum % 400 300 200 1501) 1001)
Compression set:
After 70h at standard ambient temperature, maximum % 10 10 10 151) 151)
After 22h at 70℃, maximum % 20 20 20 201) 201)
After 7d of aging in the air at 70℃:
Hardness change, maximum IRHD ±6 ±6 ±6 ±6 ±6
Tensile strength change, maximum % -15 -15 -15 -15 -15
Change in elongation at break, maximum % -25~+10 -25~+10 -25~+10 -30~+10 -40~+10
Stress relaxation in compression:
After 7d at standard ambient temperature, maximum % 15 15 15 151) 151)
After 90d at standard ambient temperature, maximum2) % 22 22 22 221) 221)
Liquid B immersion
After 7d at standard ambient temperature:
Hardness change, maximum IRHD -16 -15 -15 -14 -12
Volume change, maximum % +30 +30 +30 +30 +30
After 7d of soaking and 4d of drying in the air at 70℃:
Change in volume 2) % -15 -12 -10 -10 -10
Low temperature brittleness 2) No test pieces shall break
Temperature of test: -15℃, -25℃ or -40℃ depending on the conditions of service or transportation of the seals:
Notes:
1) The requirements for materials of preferred nominal hardness 80 or 88 IRHD shall apply only when the material is directly participating in the sealing function.
2) It is optional test, and it is required only for qualification test or when it is explicitly emphasized by the user.
4.3.1 Process quality
Processing technology of seals shall meet the requirements of relevant technical specification, seal products shall be free from pores, breaches and other defects affecting their use functions.
4.3.2 Dimensions and Tolerances
Dimensions and tolerances shall be the subject of agreement between the interested parties, and shall be chosen from the appropriate classes in GB 3672.
4.3.3 Marking, packaging, transportation and storage
If dimensions permit, seals or packing materials shall be provided with the letter "G" to indicate the use of the ring. Marking, packaging and transportation shall meet the requirements of GB 5721. The seals shall be stored according to the requirements of GB 5722.
5 Test Method
5.1 Appearance inspection
Appearance of rubber material is subject to visual inspection, appearance inspection of seal products shall be conducted according to GB 3452.2 and GB 7529. Dimensions of finished products shall be determined according to GB 5723.
Contents of HG/T 3092-1988(1997)
1 Subject Content and Application Scope
2 Normative References
3 Classification
4 Technical Requirements
5 Test Method
6 Inspection Rules
7 Marking, Packaging, Transportation and Storage
