Some standard content:
Chemical Industry Standard of the People's Republic of China
HG2178-91
Rubber Diaphragm for Domestic Gas Meters
Published on December 23, 1991
Implemented on May 1, 1992
Published by the Ministry of Chemical Industry of the People's Republic of ChinaChemical Industry Standard of the People's Republic of China
Rubber Diaphragm for Domestic Gas Meters
1 Subject Content and Scope of Application
HG2178-91
This standard specifies the classification, technical requirements, test methods, inspection rules, and marking, packaging, transportation and storage requirements for rubber diaphragms for domestic gas meters.
This standard applies to rubber diaphragms for domestic gas meters reinforced with synthetic fiber fabrics (hereinafter referred to as diaphragms).2 Reference Standards
GB1681||tt ||GB1690
GB3512
GB5721
GB5722
GB6035
Determination of tensile properties of vulcanized rubber
Test method for Shore A hardness of rubber
Determination of rebound resilience of vulcanized rubber
Test method for liquid resistance of vulcanized rubber
Test method for hot air aging of rubber
General provisions for marking, packaging and transportation of rubber sealing productsGeneral provisions for storage of rubber sealing products
Determination of tensile cold resistance coefficient of vulcanized rubber
HG4-836
Determination of crack resistance of vulcanized rubber
3 Product classification
3.1 Diaphragms are divided into two types according to their structural type: those with sealing gaskets and those without sealing gaskets. See Figure 1. With sealing gasket
3.2 The size of the diaphragm is determined by the user according to the specific requirements of the gas meter. Without sealing gasket
3.3 The diaphragm is marked with Chinese phonetic alphabetic prefixes, that is, "product name, type, standard number" Example:
HG×××x
Standard number
Main body with (without) sealing gasket
Rubber diaphragm for household gas meter
Approved by the Ministry of Chemical Industry of the People's Republic of China on December 23, 1991 and implemented on May 1, 1992wwW.bzxz.Net
Technical requirements
H G2178-91
The physical properties of rubber materials shall comply with the provisions of Table 1. 4.1
Tensile strength, MPa
Elongation at break, %
Hardness (Shore A or international hardness), degree of flex cracking, times
Hot air aging strength change rate (70℃×24F), %Tensile cold coefficient (-20℃),
Rebound resilience, %
The physical properties of the diaphragm shall comply with the provisions of Table 2. 4.2
The appearance quality of the diaphragm shall comply with the provisions of Table 3. 4.3
The size of the diaphragm shall be as specified in the drawing, and its thickness and tolerance shall be 0.2±0.02mm. Table 2
Heat resistance (130℃×1h)
Cold resistance (-15℃×1h)
Liquid resistance mass change rate (23℃x24h), %Fatigue resistance, 10,000 times
Softness, mm/m
Defect name
Surface pleating
Diaphragm rubber and skeleton delamination
Surface whitening
No abnormality on the overlapping surface of the diaphragm
The diaphragm should not have obvious hardening phenomenon
With sealing gasket
The working surface within the sealing gasket is not allowed
The sealing gasket is not allowed on the upper surface, sealing gasket The root of the ring is allowed to have a length of 1.5mm and a width of 1.0mm, not more than two places
Before production, slight mechanical processing marks and mold marks are allowed. No
No sealing gasket
No
5 Test methods
5.1 Test methods for physical properties of rubber materials
HG2178--91
5.1.1 Tensile strength and elongation at break shall be carried out in accordance with GB528. 5.1.2 Determination of hardness shall be carried out in accordance with GB6031, GB6032 or GB531. GB6031 or GB6032 methods shall be used in arbitration. 5.1.3 Determination of rebound resilience shall be carried out in accordance with GB1681. 5.1.4 Hot air aging test shall be carried out in accordance with GB3512. 5.1.5 Determination of tensile cold resistance coefficient shall be carried out in accordance with GB6035. 5.1.6 The flexure crack test shall be carried out in accordance with HG4-836.5.2 Physical property test of diaphragm
5.2.1 Heat resistance test method
The sample shall be no less than 5 pieces. Cut the sample into 60mm×20mm rectangular samples, then overlap the samples and place them on a glass plate. Place them in hot air at 130±2℃ for 1h. After taking them out, peel off the samples. There shall be no abnormality on the rubber overlapped surface.5.2.2 Cold resistance test method
The sample shall be no less than 5 pieces. Cut the sample into 60mm×20mm rectangular samples and hang them in a container at -15±1℃ for 1h. There shall be no obvious hardening phenomenon after taking them out.
5.2.3 Liquid resistance test
Liquid resistance test shall be carried out in accordance with GB1690. The mass percentage of liquids used to immerse the sample is: benzene: toluene: xylene: 120# gasoline = 30:40:20:105.2.4 Disease resistance test
Perform according to the provisions of Appendix A.
5.2.5 Softness test
Perform according to the provisions of Appendix B.
5.2.6 Determination of thickness
Measure all with a dial gauge with an accuracy of 0.01mm5.2.7 Inspection of sand holes
Must be carried out on a special light inspector. The inspector uses a 100W incandescent lamp. The distance between the lamp and the diaphragm is 250mm. 6 Inspection rules
6.1 Rubber materials
The rubber materials used in production shall be inspected for physical properties one roll at a time in accordance with the provisions of Table 1 (including hot air aging test at least once every quarter). When one of the test results is unqualified, double the sample should be taken for retesting, and the product can be put into production only after all the samples are qualified. 6.2 Diaphragm
6.2.1 The appearance quality of the diaphragm shall be fully inspected in accordance with the provisions of Table 3. 6.2.2 Physical property inspection of the diaphragm, 50,000 pieces per batch, 5 pieces for each test in accordance with the provisions of Table 2. Fatigue resistance test shall be carried out once every six months. For less than 50,000 pieces, it shall not be less than once a month. When one of the test results is unqualified, double the sample should be taken for retesting. If the retest is still unqualified, the batch of products shall be unqualified. 6.2.3 Diaphragm thickness shall be fully inspected.
7 Marking, packaging, transportation, purchase and storage
: 7.1 Marking and transportation shall be carried out in accordance with GB5721. 7.2 Packaging
HG 2178 91
The inner packaging of the diaphragm is packed in polyethylene plastic bags, with each bag containing 50, 100, 150 and 200 pieces. Each bag is separated by cardboard of the same shape as the diaphragm, and then packed into a packaging box, with no more than 3,000 pieces per box. B Storage
According to GB5722,
HG217891
Appendix A
Method for fatigue resistance test of diaphragm
(Supplement)
A1 Principle
The sample is fixed between the immovable sample clamp and the upper sample clamp (removable), and is subjected to repeated flexion actions, each action imitating the type of wrinkles that appear on the gas meter diaphragm. A2 Preparation of sample
Cut the sample into 85mm×40mm rectangular samples 5 pieces. A3 Instrument
Light leather fracture instrument (see Figure A1).
A4 Basic parameters
A4.1 Swing angle of upper clamp: 22°30
A4.2 Reciprocating speed of upper clamp: 100 times/min. A5 Test steps
A5.1 Fold the specimen relative to its length and place it on the upper clamp, with the folding line close to the upper clamp positioning plate (see Figure A2a)
A5.2 Spread the two corners of the specimen clamped outward (see Figure A2b) and then put the specimen back together and place it in the lower clamp (see Figure A2c). The part of the specimen clamped in the two clamps must be vertical, that is, the force used can only make the specimen just open: without generating tension, and then start the instrument. During the test, constantly observe the changes in the specimen and record the number of operations when the diaphragm is broken at any time. (a)
B1 Instrument
Support screw K
Positioning plate
Positioning plate
Surface to be observed during the test
HG2178—91
Upper end (reciprocating motion)
Fixer of the specimen
Lower guide plate
Appendix B
Test method for diaphragm softness
(Supplement)||tt ||Diaphragm softness tester (see Figure B1)
Figure B1 Diaphragm softness tester
Direction and range of folding movement
End sample fixing device
B2 Preparation of sample
HO2178-91
The sample can be cut into three specifications of 100mm×100mm, 100mm×80mm and 100mm×60mm. Choose any one specification during the test. The sample should be no less than 5 pieces.
B3 Test steps
Adjust the base of the softness tester to a horizontal state, then clamp the sample with a clamp along the length direction, lower the pressure plate to make it contact with the sample until the sample contacts the base. Record the weight P at this time. B4 Calculation formula
Where: S softness, g/m;
P weight, g;
Specimen length, m.
Additional notes:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Northwest Rubber Industry Products Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Tieling Rubber Industry Research and Design Institute of Liaoning Province. The main drafters of this standard are Yang Peijun, Dai Yanfen, Jiang Qingwen, Xiao Zhishi, Zhang Xin'an, and Chen Jinyang. (B1)
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