LY/T 3202-2020Bamboo winding utility tunnel (English PDF)

4.1 Classification

According to the connection mode, it can be divided into A type (socket type) and B type (bundle type).

4.2 Marking

The marking method is as follows.

5.1 Bamboo material

The basic unit of the bamboo used is bamboo strips, and its main performance should meet the requirements of Table 1.

5.2 Thermosetting resin

Should meet the requirements of Table 2.

6.1 Appearance quality

The surface should be smooth and flat, free of defects such as delamination, lack of glue, cracks, bubbles, etc.; the end surface should be flat, without burrs on the edges, and the outer surface should Flat and defect-free.

6.2 Dimensions and deviations

6.2.1 Nominal inner diameter, inner diameter size and allowable deviation

Nominal inner diameter is 2000 mm, 2200 mm, 2400 mm, 2600 mm, 2800 mm, 3000 mm, 3200 mm, 3400 mm, 3600 mm, 3800 mm, 4000 mm, 4500 mm, 5000 mm, the size of the inner diameter and its allowable deviation should conform to Table 3 Regulations.

6.2.2 Length and allowable deviation

Should meet the requirements of Table 4.

6.2.3 End face perpendicularity

Should meet the requirements of Table 5.

6.2.4 Permissible deviation of roundness

Should meet the requirements of Table 6.

6.2.5 Wall thickness

The minimum wall thickness of different ring stiffness grades should meet the requirements of Table 7.

6.2.6 Socket size

The schematic diagram of the socket is shown in Figure 2, alpha is 12°, beta is 15°; the size of the socket and its allowable deviation should meet the requirements of Table 8.

6.3 Density

0.9 g/cm3~1.0 g/cm3.

6.4 Fire resistance limit

It shall meet the requirements of section 7.1.3 of GB 50838.

6.5 Surface water absorption

Should be <=3%.

6.6 Mechanical properties

6.6.1 Ring stiffness

The ring stiffness grades are 7500 N/m2, 10 000 N/m2, 15 000 N/m2, 20 000 N/m2, 25 000 N/m2, 30 000 N/m2, Non-standard ring stiffness grade pipe gallery can be designed according to the ring stiffness formula.

6.6.2 Axial tensile strength

Should be >=10 MPa.

6.6.3 Compressive strength

Should be >=10 MPa.

6.6.4 Flexibility

The deflection level A and deflection level B shall meet the requirements of Table 9.The provisions of Table 9 are based on the long-term use of the maximum deflection of 3% Based on.

7.2 Dimensions

7.2.1 Measuring instruments

7.2.1.1 pi ruler, division value 0.2 mm and 1 mm.

7.2.1.2 Steel tape, with a graduation of 1 mm.

7.2.1.3 Steel ruler with 1 mm graduation.

7.2.2 Nominal inner diameter

Use a pi ruler with an accuracy of 0.2 mm to measure at least 3 cross-sections, and the measurement results are all within the deviation range of the large and small ends.

7.2.3 Length

Use a steel tape with an accuracy of 1mm to measure at least 3 points, the measuring points are evenly distributed, and the measurement results are calculated using 3 effective values the mean value.

7.2.4 End face perpendicularity

Measured with a steel ruler with a division value of 1 mm.

7.2.5 Roundness

Test according to GB/T 4380.

7.2.6 Wall thickness

Measure the nominal inner diameter and outer diameter on the same section of the pipe gallery; the test method of the outer diameter. use a pi ruler with an accuracy of 1 mm around the pipe gallery.

Make sure it is perpendicular to the axis of the pipe gallery) to measure the outer diameter of the pipe gallery. Then calculate the thickness of the pipe gallery of this section as the average thickness of the section.

At least three sections of the pipe gallery shall be measured. The thickness of the pipe gallery measured during the ring stiffness test should be the first choice as the test result of the wall thickness.

7.2.7 Socket size

Use a pi ruler with an accuracy of 0.2 mm around the socket of the pipe gallery (make sure it is perpendicular to the axis of the pipe gallery) to measure the outer diameter of the socket of the pipe gallery, the measurement result is the arithmetic average of 3 effective values.

7.3 Density

According to GB/T 1463 regulations.

7.4 Fire resistance limit

7.5 Surface water absorption

Cut a sample block with a length of 100±2 mm and an arc length of 100±2 mm along the axis of the pipe gallery. And put the protective layer around and inside the sample Edge banding with the same material. Test according to LY/T 2905-2017 clause 6.5, soaking time is 24h±1h, calculate according to formula (3), take the arithmetic average of the test results of 3 valid specimens is used as the test result.

7.6 Mechanical properties

7.6.1 Ring stiffness

The test equipment, test environment and test piece shall meet the requirements of GB/T 5352, and the loading speed shall be determined according to formula (4).

7.6.2 Axial tensile strength

Perform the test in accordance with Appendix A.

7.6.3 Compressive strength

Test according to GB/T 1448.

7.6.4 Flexibility

The test equipment, test environment and test piece shall meet the requirements of GB/T 5352, and the loading speed shall meet the formula (4).

After bending level A, keep it for 2 minutes and observe the condition of the test piece. If it is qualified, continue to load to the bending level B and keep it for 2 min. Observe the condition of the test piece.

condition.

7.6.5 Circumferential bending strength

Test according to GB/T 5352, and the loading speed is determined according to formula (4). Circumferential bending strength can be calculated according to formula (6), each tube has There are no less than 3 valid specimens, and the arithmetic average of the test results of 3 valid specimens is taken as the test result.

8.1 Inspection type

The inspection types are divided into factory inspection and type inspection.

8.2 Factory inspection

8.2.1 Inspection items

Appearance quality, size, ring stiffness, axial tensile strength, flexibility, hoop bending strength, compression strength.

8.2.2 Inspection plan

8.2.2.1 Each pipe gallery shall be inspected for appearance quality and size.

8.2.2.2 For a batch of 300 pipe racks with the same material, process and specifications (a batch of less than 300 pipes), one pipe shall be randomly selected Carry out inspections to test ring stiffness, axial tensile strength, flexibility, hoop bending strength, and compression strength.

8.2.3 Judgment rules

8.2.3.1 The appearance quality and size should meet the corresponding requirements, otherwise the root canal gallery shall be deemed unqualified;

8.2.3.2 If the ring stiffness, axial tensile strength, flexibility, circumferential bending strength, and compression strength meet the corresponding requirements, the batch of products shall be judged Qualified; if there are more than 2 unqualified items in the inspection, the batch of products will be deemed unqualified; if the unqualified items are not more than 2 items, the unqualified items can be added Double sampling, re-inspection, and re-inspection items should all meet the requirements; otherwise, the batch of products will be deemed unqualified.

8.3 Type inspection

8.3.1 Inspection conditions

During normal production, inspection should be carried out once a year, and type inspection should also be carried out in one of the following situations.

a) Formulation and appraisal of new products or old products for conversion trials;

b) After the official production, when the material, structure, and process of the product have major changes that may affect the product performance;

c) When the product has been suspended for a long time (more than 3 months) and then resumed production;

d) When there is a big difference between the factory inspection result and the latest type inspection result;

e) When the national market supervision and management agency requests for inspection.

8.3.2 Inspection items

All items in Chapter 6 requirements.

8.3.3 Inspection plan

Take 300 pipe racks of the same material, process and specifications as a batch (less than 300 pipes are also regarded as a batch), and use the double sampling method.

The sample size is 2.All items are checked for sampling.

8.3.4 Judgment rules

If the two samples do not meet the requirements, the type inspection is deemed unqualified. If there is 1 unqualified and no more than 2 unqualified items, the second sampling inspection can be carried out on the unqualified items. If there is no unqualified in the second sampling inspection, the type inspection shall be judged as qualified; if the second sampling If the sample is still unqualified, the type test is deemed unqualified.

9.1 Logo

Each bamboo winding pipe gallery should have at least one permanent mark, which should include the manufacturer's name (or trademark), product mark, Informatization label, batch number and product number, production date.

9.2 Lifting and transportation

Lifting and transportation shall comply with the following requirements.

a) Flexible ropes should be used for lifting. If iron chains or steel ropes are used for lifting, the contact surface of the sling and the pipe gallery should be lined with flexible objects such as rubber;

b) Double-point lifting should be used when lifting, not single-point lifting;

c) It should be fully secured during transportation, and single-stage horizontal stacking should be used;

d) During transportation, loading and unloading, there should be no severe impact.

9.3 Storage

They should be stacked according to types, specifications, and grades; the stacking site should be flat, and the stacking place should be far away from heat sources. It is not suitable for long-term storage in the open air.

When stored in the open air for more than 30 days, shading measures shall be provided; stacking is strictly prohibited.

Appendix A

(Normative appendix) Axial tensile strength test A.1 Test specimen Sampling is taken along the axis of the bamboo-wound pipe gallery. The shape and size of the test piece are shown in Figure A.1 and Table A.1.

A.2 Number of test pieces, test equipment and test procedures the number of tests and test procedures should meet the requirements of GB/T 1447, and the test equipment is shown in Figure A.2.

A.3 Test results

A.3.1 The tensile strength of the pipe gallery shall be calculated according to formula (A.1).

A.3.2 Data processing should meet the following requirements.

a) The arithmetic average of the measured values of the three specimens is used as the strength value of the specimen (accurate to 0.1MPa).

b) If the difference between the maximum or minimum of the three measured values and the median exceeds 15% of the median, the maximum and the minimum value is discarded together, and the middle value is the tensile strength value of the group of specimens.

c) If the difference between the maximum and minimum values and the median value exceeds 15% of the median value, the test results of this group of specimens are invalid.

B.1 Bundle size

The schematic diagram of the beam section is shown in Figure B.1.The nominal inner diameter (Ds) of the beam section, the length of the beam section and its allowable deviation shall meet the requirements of Table B.1.

C.1 Inspection tools Calipers, high and low temperature test chamber, diesel and gasoline.

C.2 Sampling plan

Refer to "Sampling Inspection Procedures by Attributes" GB/T 2828.

C.3 Judgment criteria for "O" ring it shall be judged according to the requirements of Table C.1, with reference to maj=0.4 for major defects and min=1.5 for minor defects.

C.4 Technical requirements for "O" ring C.4.1 The material of the "O" ring used for the connection of the bamboo winding pipe gallery is EPDM or neoprene. The size of the "O" ring should conform to the regulations in Table C.2.

set.

C.4.2 It should be checked whether the model, material, color and quantity marked on the outer packaging of the sealing ring are consistent with those listed on the delivery note.

C.4.3 It should be checked whether the seal ring matches the type, material and color marked on the outer packaging.

C.4.4 Use an electronic balance to check the quantity of each package of sealing rings by weighing. If there is insufficient, inform the purchasing department after counting the quantity.

Processing and storage in actual quantity.

C.4.5 During sampling, use a vernier caliper to measure whether the size of the sealing ring is qualified (tolerance range ±0.1cm), and the percentage of sampling the line table C.3.

C.4.6 Visually inspect each sealing ring for burrs, flashing, and damage (quantity of inspection. full inspection).

C.4.7 After passing the above inspection, it shall be classified and put into storage according to the model, material, color and number.