MT/T 668-2019Steel cord fire resistant conveyor belting for coalmine (English PDF)

3.1 Product category

Fire resistant belts can be divided into the following according to structural characteristics.

3.2 Model

Product models are divided according to longitudinal tensile strength, see Table 4.The specific models are as follows.

3.3 Specifications

3.3.1 Width

The width of the fire resistant belt is as shown in Table 1.

3.3.2 Length

The exit-factory length of the fire resistant belt shall be determined through negotiation

4.1 Appearance quality

4.1.1 The fire resistant belt shall not have edge waves.

4.1.6 There shall be no exposed steel wire rope on the fire resistant belt.

4.2 Dimensions

4.2.1 Width deviation

The width limit deviation of the fire resistant belt shall comply with the provisions of

Table 1.

4.2.2 Covering layer thickness

The thickness of the covering layer of the fire resistant belt shall comply with the requirements in Table 2.

4.2.3 Classification and configuration of tear-resistant layers

4.3 Longitudinal tensile strength

The longitudinal tensile strength of the fire resistant belt shall comply with the requirements in Table 3.

4.4 Adhesion strength

4.4.1 Wire rope's bonding strength

It shall comply with the requirements of Table 4.For wire ropes with special diameters, the bonding strength before and after aging shall not be less than (15 d + 15) N/mm, where d is the diameter of the wire rope.

4.4.2 Covering layer's bonding strength

4.4.2.1 The average bonding strength between the covering layer and the adhesive layer

shall not be less than 10 kN/m.

5.1 Sample collection

Take samples, 24 h after the product is manufactured.

5.2 Appearance quality

Use visual inspection and measuring tools for inspection.

5.3 Dimensional measurements

5.4 Longitudinal tensile strength test

Follow the provisions of GB/T 5754.2.

5.5 Adhesion strength test

5.5.1 The bonding strength of the steel wire rope shall be carried out in accordance with the provisions of GB/T 5755.The measurement of the total thickness of the belt and the thickness of the upper and lower covering layers shall be carried out, in accordance with the provisions of GB/T 5753.The difference between the total thickness of the belt and the thickness of the upper and lower covering layers is the diameter of steel wire rope d.

5.7 Covering layer performance test

5.7.1 The tensile properties of the covering layer shall be in accordance with the provisions of GB/T 528-2008.The specimen shall be cut using a type 2 [narrow parallel section width (4.0 ± 0.1) mm] dumbbell-shaped cutter.

5.7.2 The aging resistance of the covering layer shall be in accordance with the provisions of GB/T 3512.

5.12 Tensile strength test of static joint

The number of samples is 3 pieces. The sample size shall meet the requirements of

Figure 4.The width b shall be (250 ± 30) mm. The tensile speed of the holder is (100 ±

10) mm/min. The static joint's tensile strength is calculated according to formula (1).

The result is an average of 3 test results. Please refer to Appendix E, for the joint dimensions and technical requirements of the sample.

5.16.3 Equipment and test procedures

Follow the provisions of MT/T 914.

5.16.4 Result expression

The following test results shall be recorded and calculated.

5.17 Tunnel propane combustion test method

Follow the provisions of MT/T 914.

6.1 Inspection report

The inspection report shall at least include the following contents.

6.2 Exit-factory inspection

6.2.1 The product shall be inspected by the quality inspection department of the manufacturer. 1000 m is considered a batch (less than 1000 m is also considered a batch, in which the post-aging test of the covering layer is conducted once a quarter), which shall be inspected once. Only after it passes the inspection and the certificate of conformity is issued can it leave the factory.

6.2.2 See Table 9 for exit-factory inspection items.

6.3 Type inspection

6.3.3 Type inspection items are as shown in Table 9.

6.4 Determination rules

6.4.1 Qualification conditions

Those meeting the following conditions are deemed qualified.

6.4.2 Nonconformance judgment conditions

Those meeting the following conditions will be deemed unqualified.

7.1 Marking

The marking of conveyor belts shall be in accordance with the provisions of GB/T 5752.

7.2 Packaging

The fire resistant belt must be rolled and bundled firmly and neatly with a wooden core, iron core or other material mandrel. Each piece shall be covered by a packaging;

7.3 Storage and transportation

The storage and transportation of fire resistant belts shall be carried out, in accordance with the provisions of HG/T 3056.

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