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Mechanical Industry Standard of the People's Republic of China
JB/T 6620-1993
Test Method for Flexible Graphite Braided Packing
Published on 1993-05-07
Ministry of Machinery Industry of the People's Republic of China
Implementation on 1994-01-01
Mechanical Industry Standard of the People's Republic of China
Test Method for Flexible Graphite Braided Packing
1 Subject Content and Scope of Application
This standard specifies the test method, test steps and result calculation for testing the performance of flexible graphite braided packing. JB/T 66201993
This standard is applicable to non-metallic reinforced flexible graphite braided packing. Metal-reinforced flexible graphite braided packing can also be used as a reference. 2 Equipment and instruments
Balance: one with a sensitivity of 0.1mg and one with a sensitivity of 0.1g; Muffle furnace:
Electric constant temperature drying oven:
Porcelain ark, weighing bottle;
Crucible clamp:
Dryer;
Vernier caliper:
Material tensile testing machine: The force indication error should be within ±1%, and the breaking load value should be within 10%~90% of the full scale of each level of the testing machine, but not less than 4% of the maximum load of the testing machine: i.
Material universal testing machine: force indication Error 1%: Compression rate and rebound rate test device (see Figure 1); Compression rate and rebound rate test special specimen mold structure (see Figure 2), its technical requirements: (a) The parallelism of the two end surfaces of the pressure ring, bottom ring and pressure sleeve is level 6; (b) The fit between the mold core and the bottom ring and pressure ring is F8/h7; (c) The fit between the outer sleeve and the bottom ring and pressure ring is F8/h7; (d) The hardness of the pressure ring, bottom ring, mold core, and outer sleeve is 4050HRC, and the roughness R value is 1.6; 1
Magnetic base:
Micrometer, accuracy 0.002mm.
Plug rod
Micrometer
Test piece mold
Figure 1 Schematic diagram of compression rate and rebound rate test device Approved by the Ministry of Machinery Industry on May 7, 1993
Schematic diagram of test piece mold structure
Implemented on January 1, 1994
Specification measurement
JB/T 6620-1993
Use a vernier caliper to measure from two mutually perpendicular directions (accurate to 0.1mm), starting from any point of the filler, and measure once every 1m. The arithmetic mean of the three measured values is taken as the test result, and two significant figures are taken. 4 Determination of density
4.1 Sample and its preparation
Three sections of 100mm in length direction are cut vertically from the sample for testing. 4.2 Test steps
Stretch the sample straight, measure the length with a ruler (accurate to 1mm), and use a vernier caliper to measure the height and width three times at equal distances along the length direction (accurate to 0.1mm), and take the arithmetic mean. Then weigh (accurate to 0.1g). 4.3 Calculation of test results
The sample density is calculated according to formula (1):
Where: p—sample density, g/cm;
m—sample mass, g:
V—sample volume, cm.
Take the arithmetic mean of the measured values of the three samples as the test result, and take two significant figures. 5 Determination of heat loss
5.1 Sample and its preparation
Take a section of the sample at random, cut it into 2-6mm long with a stainless steel knife, and take 4-6g for test by the reduction method. 5.2 Test steps
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5.2.1 Use a weighing bottle to weigh 1±0.1g of the prepared sample, dry it in a constant temperature drying oven at 105~110℃ for 1h, take it out, and move it into a desiccator to cool for 30min.
5.2.2 Pour the sample in the weighing bottle into a porcelain ark that has been calcined at 800℃ to a constant weight, tap the porcelain ark to make the sample flat, and weigh it immediately (accurate to 0.0002g). Then put it into a muffle furnace at 450±10℃, close the furnace door and calcine for 1h. 5.2.3 Take out the porcelain ark, cool it for 1~2min, move it into a desiccator to cool it for 30min, and then weigh it (accurate to 0.0002g). 5.3 Calculation of test results
The heat loss is calculated according to formula (2):
W——heat loss,%;
G,—mass of sample before calcination, g:
Gmass of sample after calcination, g.
The arithmetic mean of the values of the three samples is taken as the test result, and three significant figures are taken. 5.4 Deviation
The difference between the maximum and minimum values of a group of test values shall not exceed 3.0%, otherwise the test shall be repeated. 6 Determination of ash
6.1 Test steps
6.1.1 Prepare the sample according to the steps of 5.1 to 5.2.1. JB/T 6620-1993
6.1.2 Pour the sample in the weighing bottle into a porcelain ark that has been pre-calcined to constant weight at 800-850℃, and weigh it immediately (accurate to 0.0002g). Place in a muffle furnace at a temperature of 800-850℃ and burn until there are no black spots. 6.1.3 Take out the porcelain ark, cool for 3-5 minutes, and place in a dryer to cool for 30 minutes. Weigh (accurate to 0.0002g). 6.1.4 Put the porcelain ark back into the muffle furnace and continue to burn for 30 minutes. Weigh according to the steps in Section 6.1.3. Repeat this process until the difference between the two weighings is less than 0.5mg. The last weighing shall prevail. 6.2 Calculation of test results
Ash content is calculated according to formula (3):
Where: A——ash content, %;
G sample mass before burning, g:
G——sample mass after burning, g.
Take the arithmetic mean of the measured values of the three samples as the test result, and take two significant figures. 6.3 Deviation
The difference between the maximum and minimum values of a set of test values shall not exceed 0.15%, otherwise the test shall be repeated. 7 Determination of tensile strength
7.1 Test specimens and their preparation
(3)
7.1.1 When the specification of the flexible graphite braided packing is less than 3mm, directly cut 5 pieces of 250mm from the incoming sample as a set of test specimens, and spread them flat on the table.
7.1.2 When the specification of the flexible graphite braided packing is not less than 3mm, use its constituent wire as the test specimen, slowly decompose the incoming sample, and randomly cut 5 pieces of 250mm as a set of test specimens, and spread them flat on the table. 7.2 Test steps
7.2.1 Weigh each test specimen (accurate to 0.01g). Measure the length of each test specimen with a ruler (accurate to 1mm). 7.2.2 Clamp the test specimen into the test machine fixture with a spacing of 200mm. Adjust the specimen so that the axis of the stretching direction coincides with the axis of the fixture, and clamp the specimen firmly, so that the specimen does not fall out of the fixture during stretching. 7.2.3 Start the testing machine, stretch at a speed of 200±50mm/min, and record the load value when the specimen breaks. 7.2.4 If the specimen breaks within 5mm from the fixture, this test is invalid and the specimen should be re-prepared for measurement. 7.3 Calculation of test results
The tensile strength is calculated according to formula (4):
Where: - tensile strength, N/g:
P breaking load, N;
mass of the tested specimen equivalent to 1m length, g. p
Take the arithmetic mean of the measured values of a group of specimens as the test result, and take three significant mathematical digits. (4)
Determination of compression rate and rebound rate
8.1 Specimens and their preparation
JB/T6620-1993
Select a special specimen mold with a core diameter that is 6 times the specification of the incoming sample. The incoming sample is tightly wrapped around the core, and the intersection is cut into a 45° angle with a blade and selected to fit. Remove and spread it flat on the table. Each group of specimens should have at least 5 pieces. 8.2 Test steps
8.2.1 For each specimen, use any one side as the reference plane, and use a vernier caliper to measure the thickness between the reference plane and its parallel surface at equidistant distances along the length direction. The arithmetic mean of the three measured values is taken as the original thickness of the specimen. 8.2.2 Place the specimen into the specimen mold with the reference surface facing up, apply the pressure ring, and then the pressure sleeve. 8.2.3 Place the specimen mold between the pressure head and the base of the testing machine, install the magnetic base and the micrometer, start the testing machine, slowly and evenly add the initial load to 1.0MPa, record the deformation after 15s, then uniformly load to 25MPa within 45s, maintain for 60s, record the deformation under the final load, then unload to the initial load, maintain for 60s, and record the deformation. 8.3 Calculation of test results
The compression rate and rebound rate are calculated according to formula (5) and formula (6) respectively: C=-x100
Arz -Aty
Af2-At
Wherein: C——compression rate, %;
R—rebound rate, %;
t——original thickness of the specimen, mm;
At—deformation under initial load, mm;
—deformation under final load, mm;
—deformation when unloaded to initial load, mm.
Take the arithmetic mean of the measured values of a group of specimens as the test result, and take three significant figures. 9
Test report
The test report shall include the following contents:
This standard number:
Product specifications, models, and manufacturers:
Test conditions;
Testing machine model:
Number and number of specimens:
Test results;
Test date and personnel.
Additional remarks:
This standard was proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Zhejiang Cixi Sealing Material Factory. The main drafter of this standard was Xu Jianrui.
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People's Republic of China
Mechanical Industry Standard
Test method for flexible graphite braided packing
JB/T 66201993
Published and distributed by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Format 880×1230
Printing sheet 1/2
Word count 8,000
First edition in January 1994
First printing in January 1994bZxz.net
Print run 1-500
Price RMB 5.00
Mechanical Industry Standard Service Network: http://www.JB.ac.cn99
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