Some standard content:
National Standard of the People's Republic of China
Difficult
Theme content and scope of application
Burning
V
Fire resistant V-belt
Belt| |tt||GB.12731 - 91
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage rules for flame-retardant V-belts. This standard applies to flame-retardant ordinary V-belts and flame-retardant narrow V-belts. Referenced standards
2
GB3686 V belt full-section tensile properties test method GB10714 V belt flame retardancy specifications and test methods GB10715 Antistatic annular V belt conductivity specified values ??and test methods GB11544 Ordinary V belt and narrow V belt V-belt size
3 Product classification
3.1
Structural type
The structure of the flame-retardant V-belt is shown in Figure 1; it consists of wrapping cloth, top glue, tensile It consists of a body, base rubber and other components. According to the structure of the tensile body, it is divided into two types: rope core V-belt (Figure 1a) and cord core V-belt (Figure 1b). Wrapping cloth
Top glue
Tensile body
Bottom glue
b
Picture 1
Note: Z, A, B, C-type cord core V-belts can be used without top glue. 3.2 Specification series
The specification series of flame-retardant V-belts are all implemented in accordance with GB11544. 3.3 Marking
3.3.1 The marking method for flame-retardant ordinary V-belts is as shown in the following example: State Administration of Technology Supervision approved 320
1992-02-01 and implemented on 1992-02-01
S
GB12731—91
A
2 Flame-retardant narrow V-band marking method is as shown in the following example: 3.3.2
ST
4 technology Requirements bzxz.net
4.1
2
9N
1400
500
The length and exposed height of the flame-retardant V-belt should comply with the regulations of GB11544. 4.2
Appearance quality:
4.2.1
Serial number
2
3
5
Flame retardant ordinary V The appearance quality of the belt should comply with the requirements in Table 1. Table 1
Defect name
Damaged corner wrapping fabric
Bubbling
The wrapping seam came off
The belt body is biased||tt| |Sponge
Basic length (mm)
Truncated type (Type A)
Flame-retardant level
Flame-retardant, electrostatically conductive mark
Length (mm ) | | tt | |The cumulative length of each side of the outer fabric shall not exceed 30% of the belt length, and the inner wrapping fabric is not allowed
not allowed
not allowed
not allowed||tt| |4.2.2 The appearance quality of flame-retardant narrow V-belts complies with the requirements in Table 2. 321
Serial number
2
3
Defect name
Ding surface bulge
Teared edge of wrapping cloth
The wrapping seam comes off
4.3 Physical and mechanical properties
4.3.1
GB1273t
Table 2
SPZ, 9 N type is not allowed | | tt | | 91 | 9 Type N is not allowed to have
products
SPA, SPB, SPC, 15N, and 25N types. The total length of the broken edge of the outer covering fabric is not allowed to exceed 25% of the belt length, and the inner wrapping fabric is not allowed to have || tt||SPZ, 9N types are not allowed to have
SPA, SPB, SPC, 15N, 25N types are allowed to have one place, but it shall not exceed 30mm long and 3mm wide. The physical and mechanical properties of flame-retardant ordinary V-belts should comply with Table 3 Provisions. Table 3
Indicators
Cut
4. 3. 2
Type
Z
B
C|| tt||D
E
Mesh
Master
Tensile strength, kN
1.0
1.8
3 . 0
5.0
9.8
14.7
The physical and mechanical properties of flame-retardant narrow V-belts should comply with the provisions of Table 4, Table 4
Indicators| |tt||Cut
Type
SPZ, 9 N
SPA
SPB, 15 N
SPC
25N||tt ||Item
4.4 Safety performance
Tensile strength, kN
2.5
3.0
5.4
9.8
12.7
Cord
14
14
14
14
14
Reference force elongation, %
14
14
14
14
14
14
Reference force elongation, %|| tt||rope core
8
8
8
8
Flame-retardant V-belts are divided into type 1 and type 2. The items are Combustibility and electrostatic conductivity. The combustion performance of type 1 is open flame, and the combustion performance of type 2 is open flame and flameless combustion.
Combustibility
4.4.1
The combustion performance of flame-retardant V-belts should comply with the requirements in Table 5. 322
Cut
Indicator
Type
Ordinary V-belt
Z
A
B
C
D
E
4.4.2
item
food
narrow V-band
SPZ, 9N| |tt||SPA
SPB, 15N
SPC
25N
Electrostatic conductivity
Self-extinguishing of six samples
Time Average value, s
Open flame
5
The resistance value of type 1 and type 2 is not greater than 6×105三5
Test method
GB12731—91
Table 5
Type 1
Maximum
self-extinguishing time of any sample, $
open melting
10
The size measurement of flame-retardant V-belts is carried out according to GB11544. 5.1
5.2
5.3
The appearance quality of flame-retardant √ belts is measured with a tape measure, a protractor and visual inspection. Six samples self-extinguishing
time average, s
open flame
5
flameless
burning
5|| tt||Type 2
Maximum
self-extinguishing time of any sample, s
Open flame
10
No flame
Combustion
12
15
The full-section tensile strength and reference force elongation of the flame-retardant V-belt are in accordance with GB3686, and the reference force is specified in Table 6 and Table 7 respectively. Table 6
Cut
Type
Reference force, kN
Poke
Type
Reference force, kN
z
0.8
SPZ, 9N
1.96
A
1.4
SPA
2.35
B
2.4
Table 7
The combustion performance test of flame-retardant V-belts is conducted according to GB10714. 5.4
The electrostatic conductivity test of flame-retardant V-belts is carried out in accordance with GB10715. 5.5 | SPB, 15N
4.31
C
3.9
SPC
7.85
D
7.8
E
11.8
25N
9.81
6.3. The sampling batch size of flame-retardant ordinary V-belts and flame-retardant narrow V-belts shall be no more than 5000A meters; in each batch of products, sufficient samples shall be taken for physical and mechanical performance inspection. But not less than once a month. 6.4 If one of the physical and mechanical properties is unqualified, double samples should be taken from the batch of products to retest the unqualified items. After the retest, if one of the samples still fails to meet the standards, the batch of products will be deemed to be unqualified. It is a defective product. 323 | Manufacture "Mington trademark;
a.
b.
c.
d.
mark or model;
matching number (Executed according to GB11544);
Manufacturing year and month.
7.2 Flame-retardant V-belts should be bundled and packaged according to the model. 7.3 Flame-retardant belts should be kept away from direct sunlight, rain and snow during transportation and storage, and should be kept clean; and should be prevented from contact with substances that affect the quality of the belt, such as acids, alkalis, oils, and organic solvents, to prevent mechanical damage, and to keep away from heat generation. Installation 1m away. 7.4 During storage, the temperature in the warehouse should be kept between -18~40℃; the relative humidity should be kept between 50% and 80%; during storage, it is necessary to avoid deformation due to excessive weight. It is best to hang the belt in a crescent shape. on the shelf or lay flat on the shelf. 7.5 In compliance with Articles 7.3 and 7.4 of this standard, the manufacturer guarantees that the physical and mechanical properties of the product will still comply with the provisions of this standard during a storage period of no more than one year from the date of manufacture.
Additional notes:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Qingdao Rubber Industry Research Institute. This standard is drafted by Shanghai Adhesive Tape Factory. The main drafters of this standard are Li Yufeng and Wu Linrong. The safety performance of this standard is equivalent to the British standard BS3790-81 "Ringular ordinary V-belt and narrow V-belt drive specifications". 324
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.