This standard applies to high-alumina heat-insulating refractory bricks. GB/T 3995-1983 High-alumina heat-insulating refractory bricks GB/T3995-1983 Standard download decompression password: www.bzxz.net

UDC E66.763.5
National Standard of the People's Republic of China
GB:3995-83
Shaped insulating refractory products- High alurmina bricks
Published on December 12, 1983
Implemented on November 1, 1984
National Standard ApprovedbZxz.net
National Standard of the People's Republic of China
Shaped insulating refractory productsHigh alumina bricks
This standard applies to high alumina insulating refractory bricks. LDC666.763.5
GB3995-83
High alumina fire bricks are used as heat insulation layer and furnace lining that is not affected by high temperature molten materials and corrosive gases. 1 Classification, shape and size
1.1 Bricks are divided into seven grades according to volume density: LG-1.0, LG-0.9, LG0.8, LG-0.7, LG-0.6, IG-0.5 and LG-0.4.
1.2 The shape and size of bricks shall comply with the provisions of GB2992-82 "Shape and Size of General Refractory Bricks". They can also be manufactured according to the customer's drawings. 1.3 Brick classification
1.3.1 Standard type
T2-3 Standard type (230mm×114mm×65mm) 1.3.2 General type, special type, special type
Those with one of the following classification characteristics and whose volume is within the specified range are respectively general type, special type and special type. 1.3.2.1 General type
No more than four scales, the overall dimension ratio is not more than 14, without concave rabbits (including arc-shaped concave corners, the same below), grooves, round eggs and holes, and the volume is 1000~2000cm2. 1.3.2.2 Special type
The overall dimension ratio is not more than 1:5, no more than one four corners, one groove, one arc, one hole belly and one angle of 50~70°, and the volume is 1000~3000cm3
1.3.2.3 Special type
The overall dimension ratio is not more than 1:6, no more than three concave corners, three grooves, three arcs, three holes and one angle of 30~50°, and the volume is 1000~5000cm3.
1.3.3 For bricks with a size greater than 400mm, a volume less than 1000cm3 and less than 5000cm2, or bricks that exceed the special requirements, the technical requirements shall be determined by agreement between the supplier and the buyer.
2 Technical requirements
2.1 The physical and chemical indicators of bricks shall comply with the requirements of Table 1. National Bureau of Standards issued on December 12, 1983, implemented on November 1, 1984, Fe2O, % not less than ... LG-0.7
The thermal conductivity of the product shall be inspected by the supplier regularly by the plate method or other methods, and shall be indicated in the quality certificate for reference. 2.2
The size tolerance and shape of the brick shall comply with the provisions of Table 2. Table 2
Dimension tolerance
Length of grain
Deepness of notch
Deepness of notch
101-250
251～400
251~400
Width≤0,5
Width>1.0
Note: 1 Cracks with a width of 0.51～1.0mm are not allowed to cross two or more floors. 2.4
Transmission of cross-sectional cracks
When the crack width is 0.05mm, it is not allowed to follow the system.
Not greater than
When the crack width is 0.51-2.0mm, the length is not greater than 30mm, and for LG-0.4, it is not greater than 60mm. 3 Test method
Chemical analysis of clay and aluminum refractory materials shall be carried out in accordance with YB365-75. m
No restrictions
No
The inspection of bulk density shall be carried out in accordance with GB2998-82 "Test method for bulk density and true porosity of fixed-color insulation refractory products". The inspection of normal temperature resistance shall be carried out in accordance with G3997.2-83 "Test method for normal temperature compressive strength of shaped insulation refractory products". 3.a
The inspection of reburning line change shall be carried out in accordance with GB3997.1-83 "Test method for reburning line change of shaped insulation refractory products". GB 3995—83
3.5 The inspection of the shape, size and cross section of bricks shall be carried out in accordance with YB84575 "Inspection Methods for Shape, Size and Cross Section of Fire-Resistant Products". 4 Inspection Rules
4.1 Batching
Bricks are batched after selection. The quantity of each batch of bricks with the grades of LG·0.7 and below LG-0.7 shall not exceed 10m2, and the quantity of each batch of bricks with other grades shall not exceed 40m3.
4.2 Sampling
Sampling shall be carried out according to the actual situation of the number of piles, rows and appearance of each batch, so as to ensure uniform intervals and comprehensive care. For the inspection of size, shape and cross section, 10 bricks shall be taken from each batch. After the size, shape and cross section are inspected and qualified, physical inspection samples shall be taken. The number of samples shall be in accordance with the provisions of Table 3. For chemical analysis samples, the average sample shall be taken from the five samples after the compressive strength test. Table 3
4.3 Acceptance
Volume density
Compressive strength at room temperature
Reburned line change
Thermal conductivity
Plate, piece
4.3.1 For the inspection of size and shape, one brick out of ten is allowed to be unqualified. For the inspection of cross-section, three bricks are taken out from ten bricks for inspection of cross-section, and all should be qualified. If it is unqualified after picking, it is allowed to turn over the pile and re-select, and re-test once. 4.3.2 The inspection of physical and chemical indicators shall be in accordance with the provisions of Table 1. The average value of several samples of each indicator must meet the technical requirements. If there are unqualified items in the inspection results, double the number of samples can be taken from the same batch of bricks at will to re-test the unqualified items. In the re-test results, even if there is one unqualified item, the whole will be regarded as unqualified. 5 Marking, packaging, transportation, storage and quality certificate 5.1 Marking
: a. Factory name,
b. Product name and brand
c. Product specifications and weight.
5.2 Packaging
Bricks should be packed in boxes or baskets (filled with soft materials) and tied tightly to prevent loosening and damage. 5.3 Transportation
Bricks should be handled with care and arranged closely during transportation and loading and unloading to avoid collision and damage. Products of different brands and brick numbers should be clearly marked and stacked neatly without mixing. Vehicles and ships carrying products must have waterproof facilities and must not be exposed to rain and water. 5.4 Bricks should be stored in warehouses or covered with cloth to prevent rain and water. 5.5 Quality certificate
Products must be accompanied by a quality certificate issued by the technical supervision department when leaving the factory, stating the test results of physical and chemical indicators. Additional Notes:
GB399583
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Fushun Refractory Materials Co., Ltd. The main drafter of this standard was Yu Wentao.
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