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With China Plastic Machinery
This standard specifies the product specifications, technical requirements, test methods, inspection rules, etc. of plastic corrugated wire tubes (hereinafter referred to as corrugated tubes) made of polyvinyl chloride (PYC) resin as the main raw material and extruded. This standard applies to the protective tubes for connecting wires of electrical devices in construction projects.
GB 2918 Standard environment for state adjustment and testing of plastic specimens
GB 2406 Oxygen index method for testing the combustion performance of plastics
GB 2828 Batch inspection counting sampling procedures and sampling tables
GB 2829 Periodic inspection counting sampling procedures and sampling tables
3.1 Marking
3.2 Marking example:
BYG-15A indicates A series polyvinyl chloride plastic corrugated wire tubes with a nominal size of 15mm.
3.3 The shape of the bellows is shown in Figure 1
3.4 Specifications
The basic dimensions of the bellows are divided into A series and B series
3.4.1 The specifications and dimensions of the A series of bellows shall comply with the requirements of Table 1, and the outer diameter deviation D¡ä of the same batch of products shall not be greater than 1.5%.
Table 1
Nominal size
Outer diameter D
Minimum inner diameter d
Length per roll, m
Limit deviation of basic size
9 14 ¡À0.3 9.2 ¡Ý100
10 16 ¡À0.3 10.7 ¡Ý100
15 20 ¡À0.4 14.1 ¡Ý100
20 25 ¡À0.4 18.3 ¡Ý50
25 30
32 ¡À0.4 24.3 ¡Ý50
32 40 ¡À0.4 31.2 ¡Ý50
40 50 ¡À0.5 39.6 ¡Ý25
50 63 ¡À0.6 50.6 ¡Ý15
The calculation formula is:
Where: D¡ä¡ª¡ªpipe outer diameter deviation, %
D¡ª¡ªpipe maximum outer diameter, mm;
D1¡ª¡ªpipe minimum outer diameter, mm;
3.4.2 B series specifications and dimensions shall comply with the requirements of Table 2.
Table 2
Nominal size
Outer diameter D
Minimum inner diameter d
Length per roll, m
Limit deviation of basic size
9 13.8 ¡À0.10 9.3 ¡Ý100
10 15.8 ¡À0.10 10.3 ¡Ý100
15 18.7 ¡À0.10 13.8 ¡Ý100
20 21.2 ¡À0.15 16.0 ¡Ý50
25 28.5 ¡À0.15 22.7 ¡Ý50
32 34.5 ¡À0.16 28.6 ¡Ý50
40 45.5 ¡À0.20 35.6 ¡Ý25
50 54.5 ¡À0.20 46.9 ¡Ý15
Note: The length of each roll of A and B series can also be determined by negotiation between the supply and demand parties.
The product should have smooth inner and outer walls and complete corrugations. Cracks, holes, bubbles, uneven colors, bright red impurities and decomposition discoloration lines are not allowed.
When the length of each roll is greater than or equal to 50m, 3 broken ends are allowed. When the length of each roll is less than 50m, 2 broken ends are allowed. The minimum pipe section length shall not be less than 10m.
Should meet the requirements of Table 3.
Table 3
Test Item Index Test Method
Flat tube diameter tubing rate, % ¡Ü25 According to Article 5.4
Tube diameter elastic recovery rate, % ¡Ü10
Thermal deformation plug gauge passed by self-weight according to Article 5.5
Normal temperature bending plug gauge passed by self-weight, no cracks according to Article 5.6
Low temperature bending plug gauge passed by self-weight, no cracks according to Article 5.7
Low temperature impact qualified according to Article 5.8
Oxygen index, % ¡Ý30 According to Article 5.9
Withstand voltage, 2kV, 15min no breakdown according to Article 5.10
If there is no special requirement, according to GB According to the provisions of 2918, the sample should be placed in an environment with a temperature of 23¡À2¡æ and a relative humidity of 45%~55% for at least 24 hours, and the test should be carried out in this environment.
Visually inspect the product from 300~500mm under natural light, and measure the length with a steel tape measure.
Use a vernier caliper with an accuracy of 0.02mm to measure the two perpendicular outer diameters of the same section, and take the arithmetic mean as the outer diameter of the section. The inner diameter is passed by the deadweight of a steel plug gauge. The plug gauge shape is shown in Figure 2 and the dimension table 4.
Table 4
Nominal size D Manufacturing tolerance Wear tolerance
A series B series
9 8.9 9 +0.05
0 0
-0.01
10 10.4 10.5
15 13.8 13.5
20 18 15.7
25 24 22.4
32 30.9 28.1
40 39.3 35.3
50 50.3 46.6
Take 3 specimens of 200mm in length. Before the test, use a vernier caliper with an accuracy of 0.02mm to measure the outer diameter of the specimen. Then place the specimen on the steel plane of the test device. At the same time, place a 50mm¡Á50mm¡Á50mm steel body in the middle of the specimen (see Figure 3). Apply pressure to the specimen at a uniform speed within 30s to reach the specified value of 450N. Keep it for 1min and read the data. Calculate the pipe diameter change rate according to (2) and take the arithmetic mean of the test results of the 3 specimens.
Where: ¦Å¡ª¡ªpipe diameter change rate, %;
D¡ª¡ªsample outer diameter before the test, mm;
D1¡ª¡ªminimum outer diameter of the same part of the specimen after the test, mm.
After the external pressure is eliminated for 1min, use a vernier caliper with an accuracy of 0.02mm to measure the minimum outer diameter of the same part. Calculate the pipe diameter elastic recovery change rate according to (3) and take the arithmetic mean of the test results of the 3 specimens.
Where: ¦Â¡ª¡ªelastic recovery change rate of pipe diameter, %;
D¡ª¡ªouter diameter of the sample before the test, mm;
D2¡ª¡ªminimum outer diameter of the same part of the sample after elastic recovery of the pipe diameter, mm.
Take 3 samples with a length of 12 times the outer diameter of the pipe, fix them on the device shown in Figure 4, place them at 60¡À2¡æ, keep them for 24 hours, and then use a steel plug gauge to inspect them. The shape of the plug gauge is shown in Figure 2, and the size is shown in Table 5. The plug gauge is qualified if it passes the deadweight test.
Table 5
Nominal size D
Manufacturing tolerance Wear tolerance
A series B series
9 7.1 7.2 +0.05
0
0
-0.01
10 8.6 8.7
15 11.3 11.0
20 14.6 12.3
25 19.4 17.8
32 25.0 22.2
40 31.7 27.7
50 41.0 37.3
Normal temperature bending test
Take 3 specimens with a length of 12 times the outer diameter of the pipe. Bend the specimens left and right once as shown in Figure 5 and keep them for 5 minutes. Use the plug gauge specified in Article 5.5 for inspection. The plug gauge is qualified if it passes the deadweight test.
Place the qualified samples of the normal-temperature bending test at -15¡À2¡æ for 2h, and then test them according to the test method in Article 5.6. Each sample should be completed within 30s.
Take 12 samples of 200mm length, place them at 60¡À2¡æ for 240h, and then place them at -15¡À2¡æ for 2h. Take them out one by one and complete an impact within 10s according to the equipment shown in Figure 6. Lift the drop hammer and observe whether the sample has cracks. More than 9 of the 12 samples are qualified if they do not crack. The free-fall impact height is 150mm. The drop hammer mass is shown in Table 6.
Table 6
Nominal size, mm Drop weight, kg
¡Ü10 0.25
15 0.5
¡Ý25 1
Perform according to GB 2406, or directly sample the pipe.
Take 3 samples of 1m in length, bend and insert copper wires as electrodes as shown in Figure 7, then place the samples in a water container with a water temperature of 20¡À2¡æ, with both ends of the samples exposed 200mm above the water surface, and make the water level in the pipe consistent with the water level in the container, place for 24h, and apply 2000V, 50Hz sinusoidal AC voltage to both poles for 15min, and if there is no breakdown, it is qualified.
6.1 Product inspection is divided into delivery inspection and routine inspection.
6.2 Acceptance inspection
6.2.1 The sampling plan for acceptance inspection shall be carried out in accordance with the one-time sampling plan in GB 2828.
6.2.2 Batching
The pipes produced with the same raw materials, formula and process are considered as a batch. The quantity of each batch shall not exceed 200 rolls. If the production volume is less than 200 rolls in 4 days, the production volume in 4 days shall be considered as a batch.
6.2.3 The product is in rolls.
6.2.4 The acceptance inspection items, sequence, inspection level and acceptable quality level (AQL) shall comply with the provisions of Table 7.
Table 7
No. Inspection Item Test Method, Clause AQL Inspection Level
1 Dimensions 5.3 6.5 ¢ò
2 Appearance 5.2
6.2.5 If the acceptance inspection fails, the batch of products shall be returned to the supplier for 100% re-inspection. If the re-inspection is qualified, it can be submitted for acceptance again, but a strict inspection must be used. If it is still unqualified after re-submission, the batch of products shall be unqualified.
6.3 Routine inspection
6.3.1 Routine inspection shall be carried out by the inspection department of the manufacturer. When the structure and main materials are not changed, flattening, room temperature bending and low temperature bending shall be carried out once every six months; voltage resistance, thermal deformation and low temperature impact shall be carried out once a year; oxygen index shall be carried out once every two years.
6.3.2 Samples for routine inspection shall be randomly selected by the quality inspection department of the manufacturer from the products that have passed the acceptance test produced in this cycle.
6.3.3 The sampling plan for routine inspection shall be carried out in accordance with the secondary sampling plan in GB 2829.
6.3.4 The items, sequence, sampling plan, discrimination level and non-conforming quality level (RQL) of routine inspection shall comply with the provisions of Table 8.
Table 8
Inspection Item Test Method, Clause Sampling Plan RQL Discrimination Level
Flat tube diameter change rate Tube diameter elastic recovery change rate 5.4 n1=n2=3
0, 2
1, 2
1.5 ¢ò
Heat deformation 5.5
Normal temperature bending 5.6
Low temperature bending 5.7
Oxygen index 5.9 n1=n2=3
0, 2
n, 2 0.65 ¢ò
Withstand voltage 5.10
Low temperature impact 5.8 n=n=3
0, 3
4, 5
2.5 ¢ò
6.3.5 If the routine inspection results meet the standard requirements, the product is qualified. If the routine inspection fails, the products within the representative period of the routine inspection shall be stopped from being delivered, and the products that have been shipped shall be negotiated with the ordering party.
7.1 The product must be packaged, and the product name, trademark, model, color, quantity, weight, volume, manufacturer, production date, and anti-pressure mark shall be indicated on the packaging.
7.2 The product shall be stored in a dry and ventilated place, away from heat sources and long-term direct exposure to sunlight.
7.3 During transportation, it shall not be pressed heavily, and sharp objects shall be avoided from severe impact.
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