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GB/T 39795-2021Conveyor belts for general purpose use—Electrical and flammability safety requirements (English PDF)

普通用途输送带导电性和可燃性安全要求

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Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

March 9, 2021

Implementation date

October 1, 2021

Scope

GB/T 39795-2021 is the English-translated version of 普通用途输送带导电性和可燃性安全要求.

GB/T 39795-2021 sets the electrical and flammability safety requirements of general purpose conveyor belts. It fixes the requirements on the electrical conductivity of the belt and on its behaviour in fire, and the safety classes into which a belt falls.

It applies to conveyor belts other than those used underground in mines. Belt makers, plant owners and safety inspectors use it. Issued on 9 March 2021, it has applied since 1 October 2021.

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Document preview — GB/T 39795-2021

National Standard of the People's Republic of China

ICS: 53.040.20
Classification: G 42

Issued by: State Administration for Market Regulation; Standardization Administration of the PRC

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Security requirements
5 Security classification

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This standard specifies the conductivity and flammability safety requirements and safety level categories of general purpose conveyor belts used by non-downhole equipment.

This standard applies to conveyor belts that are not used by downhole equipment.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 3684 Specification and Test Method for Conductivity of Conveyor Belt

GB/T 3685 Laboratory-scale test method for combustion characteristics of conveyor belts

GB/T 7986-2013 Conveyor belt roller friction test

GB/T 15706 General Principles of Mechanical Safety Design Risk Assessment and Risk Reduction

GB/T 16412 Conveyor belt propane single burner flammability test method

GB/T 33204 Lightweight conveyor belt resistance measurement

GB/T 34366 Light Conveyor Belt Measurement of Static Electric Field Generated by Light Conveyor Belt Operation

GB/T 39817 Conveyor belt propane burner medium-scale flammability test method Basic performance and application of GB/T 39825 light conveyor belt

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 Durationofafterflame

After the fire source is evacuated, there will be flame burning duration.

3.2 Flameless glowing

Burning that glows with heat (no flame).

3.3 Undamaged

The remaining part of the conveyor belt after the propane roadway combustion test did not show obvious embrittlement, cracks, bubbling or other things that were not there before. defect.

4 Security requirements

4.1 General

Various conveyor belts (1, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B, and 5C) should meet the requirements of Table 1 and 4.2~4.5.

4.2 Electrical conductivity

4.2.1 According to the test of GB/T 3684, the surface resistance of the general purpose conveyor belt is not more than 300Mohm.

4.2.2 Test according to GB/T 33204, except for the conditions specified in 4.2.3, the surface resistance of the light conveyor belt described in GB/T 39825 Not more than 300Mohm.

4.2.3 According to GB/T 34366 test, the surface voltage of the light conveyor belt with internal conductive layer is not more than 1000V.

Note: This standard only considers the static charge generated when the light conveyor belt is running at no load.

For special working conditions (such as conveying electronic components), the conductivity of the conveyor belt can be required according to the volume resistance. For the measurement method of volume resistance, see

GB/T 33204. This standard does not make safety requirements for volume resistance of light conveyor belts.

4.3 Flame resistance

4.3.1 When testing a conveyor belt of type 2A or 3A with a complete covering layer (see Chapter 5 and Table 1) according to GB/T 3685, the conveyor belt The sum of the flame duration of the 6 tests should be less than 45s, and the flame duration of any one time should not be greater than 15s.

4.3.2 According to GB/T 3685, the categories 2B, 3B, 4A, 4B, 5A, 5B and 5C with a complete cover layer and a peeled cover layer (see Chapter 5 and Table 1) When the conveyor belt is tested, the flame of each group of 6 tests (that is, 6 tests with a complete cover layer and 6 tests with a peeling cover layer)

The sum of the durations should be less than 45s, and the flame duration of any one test should not be greater than 15s.

4.4 Fire simulation

4.4.1 When testing 4A, 4B, 5A, 5B and 5C conveyor belts in accordance with GB/T 16412, the length of the conveyor belt that is not damaged at the end of the test The degree should meet the requirements of Table 1.

4.4.2 The GB/T 16412 test method is not applicable to the light conveyor belt described in GB/T 39825. Light conveyor belt is only suitable for type 1, 2A And 2B category.

4.5 Roller friction

4.5.1 According to GB/T 7986-2013 method B1 (constant load is 343N) for 3A, 3B and 4B categories (see Chapter 5 and Table 1)

During the belt test, the belt should not appear from the beginning of the test to the test time reaching 60 minutes or until the conveyor belt is worn out within 60 minutes flame.

4.5.2 According to method B2 in GB/T 7986-2013 (the maximum load is 1715N), the conveyor belt of category 5A (see Chapter 5 and Table 1) is carried out.

Test, from the start of the test to the test time reaches 150min or until the conveyor belt is worn within 150min, the belt should not appear flame.

4.5.3 According to method B2 in GB/T 7986-2013 (the maximum load is 1715N), the conveyor belt of category 5B (see Chapter 5 and Table 1) is carried out.

Test, from the start of the test to the time the test time reaches 150min or until the conveyor belt is worn out within 150min, the belt should not show flame Or flameless combustion.

4.5.4 According to method B2 in GB/T 7986-2013 (the maximum load is 1715N), carry out the conveyor belt of category 5C (see Chapter 5 and Table 1)

Test, from the start of the test to the time the test time reaches 150min or until the conveyor belt is worn out within 150min, the belt should not show flame Or flameless combustion, and the drum temperature during the test should not exceed 400 °C.

4.5.5 The test method specified in GB/T 7986-2013 is not applicable to the light conveyor belt described in GB/T 39825. Light conveyor belt only Applicable to category 1, 2A and 2B.

5 Security classification

5.1 Class 1

Conveyor belts only meet the requirements of 4.2 and are Class 1.

5.2 Category 2A

The conveyor belt meets the requirements of 4.2 and 4.3.1 and is of category 2A.

5.3 Category 2B

Conveyor belts meet the requirements of 4.2 and 4.3.2, and are of category 2B.

5.4 Category 3A

The conveyor belt meets the requirements of 4.2, 4.3.1 and 4.5.1, and is of category 3A.

If the type 3A conveyor belt cannot be tested in 4.5.1 due to the belt structure, the conveyor belt is type 2A.