Small-size Heating Furnace slide bricks and seat bricks – Allowable Tolerances and Physical Requirements
The physical requirements and tolerances specified in this standard apply to slide bricks and seat bricks used in small-size heating furnaces. Such furnaces include, but are not limited to, furnaces for laboratory, educational and industrial applications. These furnaces are generally constructed of various alternate bricks, such as high and low fire-clay slide bricks, high and low burner bricks, seat bricks, and the like.
Slide bricks and seat bricks produced in accordance with this standard will maintain dimensional stability at temperatures of approximately 1000°C. The bricks should be molded and dried in accordance with good foundry practice.
Allowable Tolerances
The edges of slide bricks and seat bricks that are expected to abut against other bricks when the furnace is assembled shall be true to a tolerance of ±0.5mm. The standard allows a more generous tolerance ±2.0mm tolerance on the opposite edges of these bricks.
The length, width and height of slide bricks and seat bricks shall be accurate to within ±1.0mm. The dimension measured across the corner of two or more edges shall be accurate to within the limits established for a measurement of the specific edges involved.
The allowable corner radius for slide bricks and seat bricks shall be up to 2.5mm, except for combinations that require greater corner radii.
Dimensional Comparison
Before a brick from one manufacturer is substituted for a brick from another, dimensional comparisons shall be made. Particular attention shall be paid to the width of the brick, the shape of the edges, the shape of the corners, and the thickness of the brick.
Surface Finish
Slide bricks and seat bricks must have a smooth, flat surface finish. As molded, all bricks shall have a smooth finish free of hollowness, lumps and bumps. The surface of the brick shall also be free of cracks and stress fractures.
Testing
As part of the quality control process, at least one sample brick of each size and type should be tested in accordance with the American Association of State Highway and Transportation Officials Standard Specifications for Brick Materials. Such testing shall include compressive strength tests, absorption tests, modulus of rupture tests, freeze-thaw tests, and sieve analysis tests.
Conclusion
This standard establishes the allowable tolerances and physical requirements for slide bricks and seat bricks used in small-size heating furnaces. Care must be taken when substituting bricks from different manufacturers to ensure dimensional compatibility. Additionally, all bricks must be tested in accordance with applicable standards to ensure proper performance.
