Some standard content:
Mechanical Industry Standard of the People's Republic of China
Agricultural Rigid Polyvinyl Fluoride Pipes
Subject Content and Scope of Application
JB/T5125-91
This standard specifies the model, specification, size, technical requirements, test methods and inspection rules of agricultural rigid polyethylene pipes (hereinafter referred to as pipes).
This standard applies to pipes that are extruded with polyvinyl chloride (PVC) as the basic raw material. 2
Cited standards
GB4219 Rigid polyvinyl chloride pipes for chemical industry
GB5836
3 Models and specifications
3.1 Model
Rigid polyvinyl chloride pipes and fittings for building drainage 3.1.1 Model indication method
3.1.2 Marking example
Working pressure, MPa
Wall thickness of pipe, mm
Outer diameter of pipe, mm
Code for smooth outer wall pipe
Rigid polyvinyl chloride pipe with smooth outer wall for agricultural use has an outer diameter of 125mm, a wall thickness of 1.5mm, and a working pressure of 0.2MPa. It is marked as follows: G125X1.5-0.2
3.2 Specifications
The specifications and dimensions of the pipe shall comply with the provisions of Table 1. Table 1
Wall corridor and
Wall thickness and
Type thickness and
1991-05-18 approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China 604
Wall thickness and
Grade, MPa
Wall thickness and
Wall thickness and
1992-01-01 implemented
Wall thickness and
Overall thickness and
JB/T51 2591
Continued Table 1
Wall thickness and
Wall friction and
Grade, MPa
Wall thickness and
Wall thickness and
4 Technical requirements
4.1 Shape, size and deviation
4.1.1 Shape
JB/T5125-91
The shape of the pipe is shown in Figure 1. Its two end faces must be sawn flat and perpendicular to the axis. Figure 1
4.1.2 Thickness deviation
The wall thickness deviation rate of the same-· loading surface of the pipe shall not be greater than 14%. 4.1.3 Length and tolerance
The length of the pipe is generally 4±0.05m and 6±0.05m. According to the needs, the supply and demand parties can negotiate to determine other lengths. 4.2 Surface quality
4.2.1 Appearance
The inner and outer walls of the pipe should be smooth and flat, and no bubbles, cracks, obvious ripples, depressions, impurities, uneven color, decomposition and discoloration lines, etc. are allowed.
The color is specified as gray. Other colors can be agreed upon by the supply and demand parties. 4.3
Straightness
When the outer diameter of the pipe is d≤32mm, the straightness is not specified; when the outer diameter is d≥40~200mm, the straightness shall not be greater than 2%, and when the outer diameter is d≥225mm, the straightness shall not be greater than 1%.
4.4 Performance indicators
The performance indicators of the pipe shall comply with the provisions of Table 2. Table 2
Vicat melting point, (
Acetone immersion
Dimension change rate, %
Fan flat test
Burst pressure, MPa
Tensile strength, MPa
Impact test
Note: P refers to the working pressure of the pipe.
No hair, shedding and fragmentation
Axial ±4.0
No blistering, scarring, etc.
Radial ±2.5
No cracks and fragmentation
90% no rupture
5 Test method
5.1 Test conditions
JB/T 5125--91
The test environment temperature is 23±2°C. The sample must be placed in the test room for at least 24 hours before the test. 5.2 Determination of the ruler
5.2.1 Determination of external control
The outer diameter of the pipe is measured with a vernier caliper with an accuracy of 0.05mm, or by measuring the circumferential length (3.142 is used as the reference) 5.2.2 Determination of length
The length of the pipe is measured with a ruler with an accuracy of 0.5cm. 5.2.3 Determination of wall thickness and its deviation
Saw the two ends of the sample flat, and measure with a measuring caliper according to the principle shown in Figure 2 (the maximum length of the adjustment The maximum and minimum wall thickness of the pipe with a length of 30 mm (short 30 mm) is the average value of the wall thickness measurement. The wall thickness deviation rate is calculated according to formula (1). 8,-8
Formula: -- Pipe wall thickness deviation rate, %;
o--The maximum wall thickness of the pipe with the same cross section, mm;;o2--The minimum wall thickness of the pipe with the same cross section, mm. Pipe
Pipe support
5.3 Inspection of surface quality
Under scattered sunlight or fluorescent lamp (illuminance of 100 ± 2lx), at a distance of about 60 cm, observe directly with the naked eye. The inner wall can be illuminated by a light source. 5.4 Determination of straightness
Use precision A ruler of 0.5 cm is used to measure the length of the shape shown in Figure 3 and the maximum height from the chord to the arc. The straightness is calculated according to formula (2) Figure 3
Where: R
Straightness.%;
L--length of the pipe.mm;
h-maximum height from the chord to the channel, mm
5.5 Determination of Vicat softening point
JB/T512591
Cut a section from each of the three test pieces, and its size, test method, etc. shall be carried out in accordance with the provisions of GB4219. 5.6 Acetone immersion test
5.6.1 Sample
Cut a section from each of the three test pieces, and its size, test method, etc. shall be carried out in accordance with the provisions of GB4219. Cut a section from each sample, the length of which is 50±2mm, and the two end surfaces should be perpendicular to the axis and polished. 5.6.2 Test method
Immerse all the samples in acetone at 20±2(C) (analytical pure reagent is used for arbitration), keep it for 2h, then take it out and observe with the naked eye for hair, shedding and fragmentation.
5.7 Determination of dimensional change rate
The determination of dimensional change rate of pipes shall be carried out in accordance with the provisions of GB4219. 5.8 Flat test
5.8.1 Sample
Cut a section from each of the three samples, the length of which is 50±2mm, and the two end surfaces should be flat and perpendicular to the axis. 5.8.2 Test equipment
Material testing machine with a flat plate compression speed of 10~25mm/min. 5.8.3 Test method
Place the sample horizontally in the middle of the lower pressure plate of the testing machine, and compress the sample at a speed of 10±5mm/min until the outer diameter of the sample is loaded. Observe the sample with the naked eye for cracks and breakage. 5.9 Determination of bursting pressure
5.9.1 Immediately unload the sample when
Cut a section from each root sample, the length of which is: 500mm when the outer diameter d≤225mm; 1000mm when the outer diameter d≥250mm. 5.9.2 Test equipment
Use an ordinary hydraulic press.
5.9.3 Test method
Heat both ends of the sample in glycerine at 120~140C until soft, put on the joints respectively, tighten the bolts evenly, then fill with 20±2( water or glycerine, and exclude air. Connect the pressure gauge, leave it for 1h, and pressurize it continuously with water or glycerine at the same temperature at a speed of 0.1MPa/min (or pressurize it rapidly and continuously within 1min) until the sample bursts. The maximum pressure value at the time of bursting is the bursting pressure. 5.10 Determination of tensile strengthbzxZ.net
5.10.1 Sample
Cut a piece from each of the three samples in the axial direction. Its shape and size shall comply with the provisions of Figure 4 and Table 3. Figure 4
40~315
Test equipment
JB/T5125-91
5kN or 10kN material testing machine with an accuracy of 1%. 5.10.3 Test method
Place the sample on the fixture of the testing machine so that it is symmetrical up and down, and the longitudinal axis coincides with the center line of tension, and the clamping is appropriate. Stretch evenly at a speed of 10N5mm/min until the sample breaks, and record the load at break and the test environment temperature. 5.10.4 Test results
Calculate the tensile strength according to formula (3):
+0.0652(t—23).
Where: .---Tensile strength at standard ambient temperature, N/mm29--Minimum wall thickness of the sample, mm;
b----Minimum value of the arc length of the sample, mm;
t-Actual temperature of the test environment, ℃;
F--Load when the sample breaks, N.
5.11 Drop hammer impact test
5.11.1 Test specimen
The size and quantity of the test specimen shall comply with the provisions of Table 4. Its two end faces shall be cut perpendicularly to the axis, and according to the outer diameter of the pipe, equidistant straight lines parallel to the axis shall be drawn on the outer surface of the test specimen. The number of equidistant straight lines drawn in Table 4
Test equipment
Falling hammer impact tester, with an accuracy of 1%.
5.11.4 Impact energy
The impact energy shall comply with the provisions of Table 5.
110~125
140~200
250~280
Test method and result processing
Perform in accordance with the provisions of GB5836.
Inspection rules
JB/T5125-91
0.25±0.005
0.25±0.005
0.5±0.005
1.5±0.005
500±10
1000±10
1000±10
1000±10
2000±10
The same specification of pipes produced under the same formula and the same process conditions is a batch, and the quantity of each batch shall not exceed 10t. If the production quantity is less than 6.1
, the output of 6 days of production period shall be considered as one batch. 6.2
Check each piece according to the provisions of Articles 4.1.1, 4.1.3, 4.2 and 4.3 of this standard. 3 For the indicators specified in Article 4.1.2 of this standard, at least half of each batch should be sampled for inspection. 6.3
4 For the performance indicators specified in Article 4.4 of this standard, randomly select two times the number of samples specified in the test method from each batch and inspect them item by item. If there are any unqualified ones, double the number will be sampled for re-inspection. If they are still unqualified, the batch of products will be judged as unqualified. 6.5 When the ordering unit conducts random inspection of product quality, it shall be carried out in accordance with the provisions of GB2828. The random inspection batch and the qualified quality level AQL value shall be agreed upon by the supply and demand parties.
Marking, packaging, transportation, storage
Pipes should be clearly marked when leaving the factory, indicating the following: a.
Manufacturer;
Product name, model, color
Production date, batch number, quantity;
Inspector code.
Pipes should be bundled according to specifications, each bundle should be of the same length and weigh no more than 100kg. Pipes with an outer diameter greater than 200mm should be packaged individually. The delivered products should have a product certificate from the quality inspection department. Pipes should not be subjected to severe impact, throwing and sun exposure during transportation. Pipes should be placed flat in a warehouse or shed with a temperature not exceeding 40C and a flat ground, and should be no less than 1m away from the heat source. The height of horizontal stacking should not exceed 2m for outer diameter d≤160mm, and should not exceed 2.5m for outer diameter d>160mm. 7.6
All pipes placed in an environment below 0°C should be placed at room temperature for one day and one night before use. Additional remarks:
This standard is proposed and managed by the Chinese Academy of Agricultural Mechanization Sciences. This standard was drafted by the Chinese Academy of Agricultural Mechanization Sciences and the Third Plastic Factory of Cangzhou City, Hebei Province. The main drafters of this standard are Zhang Xiansheng, Xu Qiushui and Zhang Weixiao. 610
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