Some standard content:
GB5725-1997
This standard is revised from GB5725~5726~-85 based on the reference to the American National Standard ANS1A10.11-1989 "Netting for people and debris for construction and demolition work", BS3913:1989 "Industrial Safety Net", GB16909-1997 "Secret Safety Vertical Net" and other standards and the investigation of domestic production, use and sales, so as to meet the needs of national economic development, scientific and technological progress and international trade.
Compared with the original standard, this standard has made the following modifications: - The original GB5725~5726-85 standards are merged into one standard. - The secret safety vertical net is added to the product classification. The technical requirements are mainly functional, and the requirements for weather resistance and flame retardancy of materials are added, and the provisions of buffer performance, setting test ropes and raw material specifications in the original standard are cancelled. —The determination of the physical and mechanical properties of ropes (lines) shall be carried out in accordance with the provisions of GB8834--88, and the original relevant test method appendix has been cancelled. The inspection rules shall implement the standards of GB2828-87 and GB2829-87. In order to ensure safety, this standard shall be used in conjunction with relevant standards and the "Safety Net Installation Regulations". From the date of entry into force, this standard will replace GB5725~5726-85 at the same time. Appendix A of this standard is the appendix of the standard; Appendix B is the appendix of the reminder. This standard is proposed by the Ministry of Labor of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Labor Protection Products. The drafting unit of this standard: Shanghai Institute of Labor Protection Science. The main drafters of this standard: Wang Huaiqing, Li Jianjun, Yin Zhaoyang, Yin Jianguo, Wang Zhigang, and Sun Deshui. 36
1 Scope
National Standard of the People's Republic of China
Safety nets
GB 5725--1997
Replaces GB5725~5726-85
This standard specifies the definition, product classification, technical requirements, inspection methods, inspection rules and marking, packaging, transportation, storage and other requirements of safety nets.
This standard applies to safety nets used for high-altitude operations such as construction. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB2828-87 Batch-by-batch inspection counting sampling procedure and sampling table (applicable to the inspection of continuous batches) GB2829-87 Periodic inspection counting sampling procedure and sampling table (applicable to the inspection of the stability of the production process) GB4609-84 Plastic combustion performance test method Vertical combustion method GB8834--88 Determination of relevant physical and mechanical properties of ropes GB/T14522-93 Artificial climate accelerated test method for plastics, coatings and rubber materials for mechanical industrial products GB16909-1997 American-style safety vertical net
3 Definitions
This standard adopts the following definitions.
3.1 Safety nets
Nets used to prevent people and objects from falling, or to avoid and reduce injuries caused by falling and hitting objects. Safety nets are generally composed of net bodies, side ropes, tethers and other components.
3.2 Net body
The net-like material made of monofilament, thread, rope, etc. through weaving or other net-making processes, which constitutes the main body of the safety net. 3.3 Side rope
The rope connected to the net body along the edge of the net body.
3.4 Tied rope
The rope used to fix the safety net on the support
3.5 Tendon rope
The rope regularly passed through the net body to increase the strength of the safety net. 3. 6 Length of the rhombus and rectangle mesh The distance between two adjacent net rope knots or nodes. 3.7 Specification
The specifications of the safety net are expressed by its width (height) and length, in meters. Approved by the State Administration of Technical Supervision on July 7, 1997 and implemented on January 1, 1998
3.8 Setting surface
The plane where the safety net support point is located.
3.9 Horizontal safety net GB 5725--1997
A safety net used to prevent people or objects from falling when the setting plane is not perpendicular to the horizontal plane. 3.10 Vertical safety net A safety net used to prevent people or objects from falling when the setting plane is perpendicular to the horizontal plane. 3.11 Fine mesh safety vertical net A net with a mesh density of not less than 800 mesh/100cm, installed perpendicular to the horizontal plane to prevent people from falling and falling objects from injuring. -Generally composed of a net body, eyelet buckles, side ropes and additional tethers. [GB 16909—1997] 4 Classification and marking
4.1 According to the function, the products are divided into three categories:
a) flat net;
b) vertical net;
c) close-mesh safety vertical net.
4.2 The product marking consists of three parts: name, category and specification. The letters P, L and ML represent flat net, vertical net and close-mesh safety vertical net respectively. 4.3 Marking examples:
Example 1: 3m wide, 6m long nylon flat net:
Nylon safety net-P-3×6GB5725
Example 2: 1.8 wide, 6m long close-mesh safety vertical net: ML-1.8X6GB 16909
Example 3: 4m wide (high), 6m long flame-retardant vinyl vertical net: flame-retardant vinyl safety net-L-4X×6GB57255Technical requirements
5.1 The safety net can be made of nylon, vinylon, polyester or other materials with weather resistance not less than the above varieties (weather resistance). 5.2 The materials, specifications and manufacturing methods of the same components on the same safety net must be consistent. The appearance should be flat. 5.3 The width of the flat net shall not be less than 3m, the width (height) of the vertical net shall not be less than 1.2m, and the width (height) of the close-mesh safety vertical net shall not be less than 1.2m. Product specification deviation: allowed to be less than ±2%. The weight of each safety net should not exceed 15kg. 5.4 The side length of the diamond or square mesh safety net shall not exceed 8cm. 5.5 The connection between the side rope and the net body must be firm. The breaking strength of the side rope of the flat net shall not be less than 7000N; the breaking strength of the side rope of the vertical net shall not be less than 3000N.
5.6 The tethers are evenly distributed along the edge of the net, and the distance between two adjacent tethers shall comply with the provisions of Table 1. The length shall not be less than 0.8m. When the tendon rope and the tether are used together, the tether part must be lengthened, and after being tied with the side rope, it is folded back to the side rope and tied to form at least two ropes. Table 1
Safety net category
Dense mesh safety vertical net
The distance between two adjacent tethers, m
5.7 The distribution of the tendon ropes should be reasonable. The distance between two adjacent tendon ropes on the flat net shall not be less than 30cm, and the breaking strength of the tendon rope shall not exceed 3000N. 5.8 The breaking strength of the net body (mesh or net rope) shall comply with the corresponding product standards. 5.9 All nodes of the safety net must be fixed.
GB5725--1997
The impact performance of the safety net shall comply with the provisions of Table 2 after testing according to the method specified in Appendix A. 5.10
Safety net category
Impact height, m
Test results
Net rope, side rope, tie rope do not break
Net rope, side rope, tie rope do not break
5.11 Technical requirements for close-mesh safety vertical nets shall comply with the provisions of GB16909. 5.12 Flame-retardant safety nets must be flame-retardant, and their afterburning and smoldering time shall not exceed 4s. 6 Inspection methods
6.1 Material weathering performance test shall be carried out in accordance with the provisions of 4.2 in GB/T14522-93. 6.2 Visual inspection shall be adopted for appearance inspection.
Close-mesh safety vertical netbzxZ.net
Complies with the provisions of GB16909
6.3 The specifications and mesh side length are measured by a steel tape measure (accuracy not less than 1mm), and the weight is measured by a scale (accuracy not less than 0.05kg). 6.4 The breaking strength test of the rope shall be carried out in accordance with the provisions of GB8834. 6.5 The impact test shall be carried out in accordance with the provisions of Appendix A. 6.6 The flame retardancy test of the flat net and the vertical net shall be carried out in accordance with the provisions of GB4609 (the test rope diameter shall not exceed 7mm). 6.7 The test method of the close-mesh safety vertical net shall be carried out in accordance with the provisions of GB16909. 7 Inspection rules
7.1 Inspection is divided into factory inspection and type inspection: 7.1.1 Items included in the factory inspection:
a) Appearance (5.2, 5.9), specifications, weight (5.3), mesh side length (5.4); b) the breaking strength of the edge rope and tendon rope;
c) impact resistance;
d) penetration resistance (applicable to close-mesh safety vertical net); e) flame retardant performance (applicable to flame retardant safety net). 7.1.2 Type inspection includes all items specified in 5.1 to 5.12. 7.2 Type test should be carried out in any of the following situations: a) trial production and identification of new products or old products transferred to the factory for production; b) after formal production, if there are major changes in structure, materials, and processes, which may affect product performance; c) when mass production is carried out in batches, a periodic inspection is carried out once a year; d) when the product is resumed after long-term suspension of production; e) when the factory inspection results are significantly different from the first type inspection; f) when the national quality supervision agency puts forward type inspection requirements. 7.3 Factory inspection is carried out batch by batch according to the one-time sampling plan specified in GB2828. 7.3.1 The product is a batch of one production batch, but the maximum number shall not exceed 3,000 sheets. The sample size, inspection level, unqualified classification, qualified quality level and judgment array of each test are shown in Table 3. 39
Inspection items
Rope breaking strength
God-strike test
Flame retardancy
Batch range
51~150
151～500
501～3000
51~500
501～3000
16～50
51～150
151～500
501～3000
51～500| |tt||501~～3000
51~~500
501~3000
51~500
501～3000
Sample size
GB5725-1997
Inspection level
Unqualified classification
Qualified quality level
Judgment array
Qualified judgment number
Unqualified judgment number
7.4 Type inspection shall be carried out in accordance with the provisions of GB2829, with discrimination level DL=I, unqualified quality level RQL50, sample n-3, qualified judgment number A. =0, unqualified judgment number R. 1. Sampling plan 8 Marking, packaging, transportation and storage
8.1 Product marking includes the following:
a) Product name and classification mark;
b) Mesh side length;
c) Manufacturer name and address;
d) Trademark;
e) Manufacturing date (or number) or production batch number;
g) Other contents that must be filled in according to relevant regulations, such as production license number, etc. 8.2 Each safety net should be packaged independently with plastic film, paper bag, etc., with product instructions, factory inspection certificate and other documents that must be provided according to relevant regulations (such as safety certification, etc.). The outer packaging can be cartons, polypropylene film bags, etc., which should have the following marks: a) product name and trademark;
b) manufacturer name and address;
c) quantity, gross weight, net weight and volume;
d) manufacturing date or production batch number;
e) matters or marks to be noted during transportation, etc. 8.3 During storage and transportation, the safety net must be ventilated, light-proof, and heat-insulated, and at the same time avoid the invasion of chemicals. When transporting bagged safety nets, it is forbidden to use hooks.
8.4 For those with a storage period of more than two years, 0.2% sampling shall be carried out. If there are less than 1,000 sheets, 2 sheets shall be sampled for impact test. They can be sold and used only after meeting the requirements of 5.10 and 5.11.
A1 Principle
GB5725--1997
Appendix A
(Appendix to the standard)
Safety net impact test method
Use a special test device to make a simulated human-shaped sandbag fall freely from a specified height into the test net, and judge the impact resistance of the safety net according to its degree of damage.
A2 Test device and tools
A2.1 A simulated human-shaped sandbag with a length of 100cm, a bottom area of 2800cm2, and a weight of 100kg±2kg. A2.2 A test bench capable of lifting and releasing the simulated human-shaped sandbag to make it fall freely at a specified position. A2.3 Rigid test frame
a) 6m long, 3m wide, and not less than 2.5m high, welded with steel pipes of not less than g100mm×5mm, with a total weight of not less than 200kg (for flat net and vertical net tests).
b) The close-mesh safety vertical net shall be tested in accordance with the relevant provisions of GB16909. A3 Test specimen
The test specimen is a 3m×6m flat net or vertical net.
A4 Test method
A4.1 The impact test points of the flat net or vertical net are shown in Figure A1. Test net
A type of impact test point
A4.2 The impact test of the close-mesh safety vertical net shall be carried out in accordance with the relevant provisions of GB16909. A4.3 The long side of the simulated human sandbag for the impact test shall be: a) Diamond mesh safety net: parallel to the long side of the safety net; b) Square mesh safety net: parallel to the short side of the safety net. 42
A5 Test steps
A5.1 Fasten the test net firmly to the test frame. GB5725—1997
A5.2 Use the lifting and releasing mechanism of the test bench to lift the simulated humanoid sandbag to the top of the test point, so that the distance between its bottom surface and the plane where the test frame is located is equal to the test height, and adjust its direction according to the regulations. Then release the simulated humanoid sandbag to let it fall freely. A6 Test result evaluation
Perform according to the provisions of Table 2.
Appendix B
(Suggestive Appendix)
General rules for the use of safety nets
B1 Precautions during installation
B1.1 Each tether on the safety net should be tied to the bracket, and the surrounding ropes (edges) should be close to the bracket. The tying should meet the principles of easy knotting, firm connection and easy untying, and will not fall apart after being stressed during work. When installing a safety net with reinforcing ropes, the reinforcing ropes should also be connected to the bracket. B1.2 The flat net surface should not be stretched too tight. When the height difference between the net surface and the working surface is greater than 5m, its extended length should be greater than 4m. When the height difference between the net surface and the working surface is less than 5m, its extended length should be greater than 3m. The minimum distance between the flat net and the surface of the object below should not be less than 3m. The distance between two layers of flat nets shall not exceed 10m.
B1.3 The vertical net surface should be perpendicular to the horizontal plane, and the maximum gap with the edge of the working surface shall not exceed 10cm. B1.4 The installed safety net should be inspected by a special person before use. B2 Use
B2.1 When using, the following phenomena should be avoided: a) arbitrarily dismantling the components of the safety net;
b) people jumping into or throwing objects into the safety net; c) a large number of welding or other sparks falling into the safety net; d) objects are piled up in or below the safety net; e) there is severe corrosive smoke around the safety net. B2.2 Safety nets in use should be inspected regularly or irregularly, and pollution from falling objects on the nets should be cleaned up in time. When they are hit hard, they should be replaced in time.
B3 Management
Safety nets should be kept and issued by designated personnel, and those not in use should be stored in warehouses or special places that are ventilated, light-proof, heat-insulated, and free of chemical pollution.1 The product is produced in batches of one time, but the maximum batch size shall not exceed 3,000 sheets. The sample size, inspection level, unqualified classification, qualified quality level and judgment array of each test are shown in Table 3.39
Inspection items
Rope breaking strength
Strike test
Flame retardancy
Batch range
51~150
151～500
501～3000
51~500
501～3000
16～50
51～150
151～500
501～3000
51～500| |tt||501~～3000
51~~500
501~3000
51~500
501～3000
Sample size
GB5725-1997
Inspection level
Unqualified classification
Qualified quality level
Judgment array
Qualified judgment number
Unqualified judgment number
7.4 Type inspection shall be carried out in accordance with the provisions of GB2829, with discrimination level DL=I, unqualified quality level RQL50, sample n-3, qualified judgment number A. =0, unqualified judgment number R. 1. Sampling plan 8 Marking, packaging, transportation and storage
8.1 Product marking includes the following:
a) Product name and classification mark;
b) Mesh side length;
c) Manufacturer name and address;
d) Trademark;
e) Manufacturing date (or number) or production batch number;
g) Other contents that must be filled in according to relevant regulations, such as production license number, etc. 8.2 Each safety net should be packaged independently with plastic film, paper bag, etc., with product instructions, factory inspection certificate and other documents that must be provided according to relevant regulations (such as safety certification, etc.). The outer packaging can be cartons, polypropylene film bags, etc., which should have the following marks: a) product name and trademark;
b) manufacturer name and address;
c) quantity, gross weight, net weight and volume;
d) manufacturing date or production batch number;
e) matters or marks to be noted during transportation, etc. 8.3 During storage and transportation, the safety net must be ventilated, light-proof, and heat-insulated, and at the same time avoid the invasion of chemicals. When transporting bagged safety nets, it is forbidden to use hooks.
8.4 For those with a storage period of more than two years, 0.2% sampling shall be carried out. If there are less than 1,000 sheets, 2 sheets shall be sampled for impact test. They can be sold and used only after meeting the requirements of 5.10 and 5.11.
A1 Principle
GB5725--1997
Appendix A
(Appendix to the standard)
Safety net impact test method
Use a special test device to make a simulated human-shaped sandbag fall freely from a specified height into the test net, and judge the impact resistance of the safety net according to its degree of damage.
A2 Test device and tools
A2.1 A simulated human-shaped sandbag with a length of 100cm, a bottom area of 2800cm2, and a weight of 100kg±2kg. A2.2 A test bench capable of lifting and releasing the simulated human-shaped sandbag to make it fall freely at a specified position. A2.3 Rigid test frame
a) 6m long, 3m wide, and not less than 2.5m high, welded with steel pipes of not less than g100mm×5mm, with a total weight of not less than 200kg (for flat net and vertical net tests).
b) The close-mesh safety vertical net shall be tested in accordance with the relevant provisions of GB16909. A3 Test specimen
The test specimen is a 3m×6m flat net or vertical net.
A4 Test method
A4.1 The impact test points of the flat net or vertical net are shown in Figure A1. Test net
A type of impact test point
A4.2 The impact test of the close-mesh safety vertical net shall be carried out in accordance with the relevant provisions of GB16909. A4.3 The long side of the simulated human sandbag for the impact test shall be: a) Diamond mesh safety net: parallel to the long side of the safety net; b) Square mesh safety net: parallel to the short side of the safety net. 42
A5 Test steps
A5.1 Fasten the test net firmly to the test frame. GB5725—1997
A5.2 Use the lifting and releasing mechanism of the test bench to lift the simulated humanoid sandbag to the top of the test point, so that the distance between its bottom surface and the plane where the test frame is located is equal to the test height, and adjust its direction according to the regulations. Then release the simulated humanoid sandbag to let it fall freely. A6 Test result evaluation
Perform according to the provisions of Table 2.
Appendix B
(Suggestive Appendix)
General rules for the use of safety nets
B1 Precautions during installation
B1.1 Each tether on the safety net should be tied to the bracket, and the surrounding ropes (edges) should be close to the bracket. The tying should meet the principles of easy knotting, firm connection and easy untying, and will not fall apart after being stressed during work. When installing a safety net with reinforcing ropes, the reinforcing ropes should also be connected to the bracket. B1.2 The flat net surface should not be stretched too tight. When the height difference between the net surface and the working surface is greater than 5m, its extended length should be greater than 4m. When the height difference between the net surface and the working surface is less than 5m, its extended length should be greater than 3m. The minimum distance between the flat net and the surface of the object below should not be less than 3m. The distance between two layers of flat nets shall not exceed 10m.
B1.3 The vertical net surface should be perpendicular to the horizontal plane, and the maximum gap with the edge of the working surface shall not exceed 10cm. B1.4 The installed safety net should be inspected by a special person before use. B2 Use
B2.1 When using, the following phenomena should be avoided: a) arbitrarily dismantling the components of the safety net;
b) people jumping into or throwing objects into the safety net; c) a large number of welding or other sparks falling into the safety net; d) objects are piled up in or below the safety net; e) there is severe corrosive smoke around the safety net. B2.2 Safety nets in use should be inspected regularly or irregularly, and pollution from falling objects on the nets should be cleaned up in time. When they are hit hard, they should be replaced in time.
B3 Management
Safety nets should be kept and issued by designated personnel, and those not in use should be stored in warehouses or special places that are ventilated, light-proof, heat-insulated, and free of chemical pollution.1 The product is produced in batches of one time, but the maximum batch size shall not exceed 3,000 sheets. The sample size, inspection level, unqualified classification, qualified quality level and judgment array of each test are shown in Table 3.39
Inspection items
Rope breaking strength
Strike test
Flame retardancy
Batch range
51~150
151～500
501～3000
51~500
501～3000
16～50
51～150
151～500
501～3000
51～500| |tt||501~～3000
51~~500
501~3000
51~500
501～3000
Sample size
GB5725-1997
Inspection level
Unqualified classification
Qualified quality level
Judgment array
Qualified judgment number
Unqualified judgment number
7.4 Type inspection shall be carried out in accordance with the provisions of GB2829, with discrimination level DL=I, unqualified quality level RQL50, sample n-3, qualified judgment number A. =0, unqualified judgment number R. 1. Sampling plan 8 Marking, packaging, transportation and storage
8.1 Product marking includes the following:
a) Product name and classification mark;
b) Mesh side length;
c) Manufacturer name and address;
d) Trademark;
e) Manufacturing date (or number) or production batch number;
g) Other contents that must be filled in according to relevant regulations, such as production license number, etc. 8.2 Each safety net should be packaged independently with plastic film, paper bag, etc., with product instructions, factory inspection certificate and other documents that must be provided according to relevant regulations (such as safety certification, etc.). The outer packaging can be cartons, polypropylene film bags, etc., which should have the following marks: a) product name and trademark;
b) manufacturer name and address;
c) quantity, gross weight, net weight and volume;
d) manufacturing date or production batch number;
e) matters or marks to be noted during transportation, etc. 8.3 During storage and transportation, the safety net must be ventilated, light-proof, and heat-insulated, and at the same time avoid the invasion of chemicals. When transporting bagged safety nets, it is forbidden to use hooks.
8.4 For those with a storage period of more than two years, 0.2% sampling shall be carried out. If there are less than 1,000 sheets, 2 sheets shall be sampled for impact test. They can be sold and used only after meeting the requirements of 5.10 and 5.11.
A1 Principle
GB5725--1997
Appendix A
(Appendix to the standard)
Safety net impact test method
Use a special test device to make a simulated human-shaped sandbag fall freely from a specified height into the test net, and judge the impact resistance of the safety net according to its degree of damage.
A2 Test device and tools
A2.1 A simulated human-shaped sandbag with a length of 100cm, a bottom area of 2800cm2, and a weight of 100kg±2kg. A2.2 A test bench capable of lifting and releasing the simulated human-shaped sandbag to make it fall freely at a specified position. A2.3 Rigid test frame
a) 6m long, 3m wide, and not less than 2.5m high, welded with steel pipes of not less than g100mm×5mm, with a total weight of not less than 200kg (for flat net and vertical net tests).
b) The close-mesh safety vertical net shall be tested in accordance with the relevant provisions of GB16909. A3 Test specimen
The test specimen is a 3m×6m flat net or vertical net.
A4 Test method
A4.1 The impact test points of the flat net or vertical net are shown in Figure A1. Test net
A type of impact test point
A4.2 The impact test of the close-mesh safety vertical net shall be carried out in accordance with the relevant provisions of GB16909. A4.3 The long side of the simulated human sandbag for the impact test shall be: a) Diamond mesh safety net: parallel to the long side of the safety net; b) Square mesh safety net: parallel to the short side of the safety net. 42
A5 Test steps
A5.1 Fasten the test net firmly to the test frame. GB5725—1997
A5.2 Use the lifting and releasing mechanism of the test bench to lift the simulated humanoid sandbag to the top of the test point, so that the distance between its bottom surface and the plane where the test frame is located is equal to the test height, and adjust its direction according to the regulations. Then release the simulated humanoid sandbag to let it fall freely. A6 Test result evaluation
Perform according to the provisions of Table 2.
Appendix B
(Suggestive Appendix)
General rules for the use of safety nets
B1 Precautions during installation
B1.1 Each tether on the safety net should be tied to the bracket, and the surrounding ropes (edges) should be close to the bracket. The tying should meet the principles of easy knotting, firm connection and easy untying, and will not fall apart after being stressed during work. When installing a safety net with reinforcing ropes, the reinforcing ropes should also be connected to the bracket. B1.2 The flat net surface should not be stretched too tight. When the height difference between the net surface and the working surface is greater than 5m, its extended length should be greater than 4m. When the height difference between the net surface and the working surface is less than 5m, its extended length should be greater than 3m. The minimum distance between the flat net and the surface of the object below should not be less than 3m. The distance between two layers of flat nets shall not exceed 10m.
B1.3 The vertical net surface should be perpendicular to the horizontal plane, and the maximum gap with the edge of the working surface shall not exceed 10cm. B1.4 The installed safety net should be inspected by a special person before use. B2 Use
B2.1 When using, the following phenomena should be avoided: a) arbitrarily dismantling the components of the safety net;
b) people jumping into or throwing objects into the safety net; c) a large number of welding or other sparks falling into the safety net; d) objects are piled up in or below the safety net; e) there is severe corrosive smoke around the safety net. B2.2 Safety nets in use should be inspected regularly or irregularly, and pollution from falling objects on the nets should be cleaned up in time. When they are hit hard, they should be replaced in time.
B3 Management
Safety nets should be kept and issued by designated personnel, and those not in use should be stored in warehouses or special places that are ventilated, light-proof, heat-insulated, and free of chemical pollution.11 requirements before they can be sold and used.
A1 Principle
GB5725--1997
Appendix A
(Appendix to the standard)
Safety net impact test method
Use a special test device to make a simulated human-shaped sandbag fall freely from a specified height into the test net, and judge the impact resistance of the safety net according to its degree of damage.
A2 Test device and tools
A2.1 A simulated human-shaped sandbag with a length of 100cm, a bottom area of 2800cm2, and a weight of 100kg±2kg. A2.2 A test bench capable of lifting and releasing the simulated human-shaped sandbag to make it fall freely at a specified position. A2.3 Rigid test frame
a) 6m long, 3m wide, not less than 2.5m high, welded with steel pipes not less than g100mm×5mm, with a total weight of not less than 200kg (for flat net and vertical net test).
b) Close-mesh safety vertical net shall be tested in accordance with the relevant provisions of GB16909. A3 Test specimen
The test specimen is a 3m×6m flat net or vertical net.
A4 Test method
A4.1 The impact test points of the flat net or vertical net are shown in Figure A1. Test net
A type of impact test point
A4.2 The impact test of the close-mesh safety vertical net shall be carried out in accordance with the relevant provisions of GB16909. A4.3 The long side of the simulated human sandbag for the impact test shall be: a) Diamond mesh safety net: parallel to the long side of the safety net; b) Square mesh safety net: parallel to the short side of the safety net. 42
A5 Test steps
A5.1 Tie the test net firmly to the test frame. GB5725—1997
A5.2 Use the lifting and releasing mechanism of the test bench to lift the simulated human sandbag to the top of the test point, so that the distance between its bottom surface and the plane where the test frame is located is equal to the test height, and adjust its direction according to the regulations. Then release the simulated human sandbag to let it fall freely. A6 Test result evaluation
Perform according to the provisions of Table 2.
Appendix B
(Suggestive Appendix)
General rules for the use of safety nets
B1 Precautions during installation
B1.1 Each tie rope on the safety net should be tied to the bracket, and the surrounding ropes (edges) should be close to the bracket. The tying should meet the principles of easy knotting, firm connection and easy untying, and will not fall apart after being stressed during work. When installing a safety net with reinforcing ropes, the reinforcing ropes should also be connected to the bracket. B1.2 The flat net surface should not be stretched too tight. When the height difference between the net surface and the working surface is greater than 5m, its extended length should be greater than 4m. When the height difference between the net surface and the working surface is less than 5m, its extended length should be greater than 3m. The minimum distance between the flat net and the surface of the object below should not be less than 3m. The distance between two layers of flat nets shall not exceed 10m.
B1.3 The vertical net surface should be perpendicular to the horizontal plane, and the maximum gap with the edge of the working surface shall not exceed 10cm. B1.4 The installed safety net should be inspected by a special person before use. B2 Use
B2.1 When using, the following phenomena should be avoided: a) arbitrarily dismantling the components of the safety net;
b) people jumping into or throwing objects into the safety net; c) a large number of welding or other sparks falling into the safety net; d) objects are piled up in or below the safety net; e) there is severe corrosive smoke around the safety net. B2.2 Safety nets in use should be inspected regularly or irregularly, and pollution from falling objects on the nets should be cleaned up in time. When they are hit hard, they should be replaced in time.
B3 Management
Safety nets should be kept and issued by designated personnel, and those not in use should be stored in warehouses or special places that are ventilated, light-proof, heat-insulated, and free of chemical pollution.11 requirements before they can be sold and used.
A1 Principle
GB5725--1997
Appendix A
(Appendix to the standard)
Safety net impact test method
Use a special test device to make a simulated human-shaped sandbag fall freely from a specified height into the test net, and judge the impact resistance of the safety net according to its degree of damage.
A2 Test device and tools
A2.1 A simulated human-shaped sandbag with a length of 100cm, a bottom area of 2800cm2, and a weight of 100kg±2kg. A2.2 A test bench capable of lifting and releasing the simulated human-shaped sandbag to make it fall freely at a specified position. A2.3 Rigid test frame
a) 6m long, 3m wide, not less than 2.5m high, welded with steel pipes not less than g100mm×5mm, with a total weight of not less than 200kg (for flat net and vertical net test).
b) Close-mesh safety vertical net shall be tested in accordance with the relevant provisions of GB16909. A3 Test specimen
The test specimen is a 3m×6m flat net or vertical net.
A4 Test method
A4.1 The impact test points of the flat net or vertical net are shown in Figure A1. Test net
A type of impact test point
A4.2 The impact test of the close-mesh safety vertical net shall be carried out in accordance with the relevant provisions of GB16909. A4.3 The long side of the simulated human sandbag for the impact test shall be: a) Diamond mesh safety net: parallel to the long side of the safety net; b) Square mesh safety net: parallel to the short side of the safety net. 42
A5 Test steps
A5.1 Tie the test net firmly to the test frame. GB5725—1997
A5.2 Use the lifting and releasing mechanism of the test bench to lift the simulated human sandbag to the top of the test point, so that the distance between its bottom surface and the plane where the test frame is located is equal to the test height, and adjust its direction according to the regulations. Then release the simulated human sandbag to let it fall freely. A6 Test result evaluation
Perform according to the provisions of Table 2.
Appendix B
(Suggestive Appendix)
General rules for the use of safety nets
B1 Precautions during installation
B1.1 Each tie rope on the safety net should be tied to the bracket, and the surrounding ropes (edges) should be close to the bracket. The tying should meet the principles of easy knotting, firm connection and easy untying, and will not fall apart after being stressed during work. When installing a safety net with reinforcing ropes, the reinforcing ropes should also be connected to the bracket. B1.2 The flat net surface should not be stretched too tight. When the height difference between the net surface and the working surface is greater than 5m, its extended length should be greater than 4m. When the height difference between the net surface and the working surface is less than 5m, its extended length should be greater than 3m. The minimum distance between the flat net and the surface of the object below should not be less than 3m. The distance between two layers of flat nets shall not exceed 10m.
B1.3 The vertical net surface should be perpendicular to the horizontal plane, and the maximum gap with the edge of the working surface shall not exceed 10cm. B1.4 The installed safety net should be inspected by a special person before use. B2 Use
B2.1 When using, the following phenomena should be avoided: a) arbitrarily dismantling the components of the safety net;
b) people jumping into or throwing objects into the safety net; c) a large number of welding or other sparks falling into the safety net; d) objects are piled up in or below the safety net; e) there is severe corrosive smoke around the safety net. B2.2 Safety nets in use should be inspected regularly or irregularly, and pollution from falling objects on the nets should be cleaned up in time. When they are hit hard, they should be replaced in time.
B3 Management
Safety nets should be kept and issued by designated personnel, and those not in use should be stored in warehouses or special places that are ventilated, light-proof, heat-insulated, and free of chemical pollution.
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