We have outlined numerous scenarios where the use of wear-resistant Rubber Linings is essential. As equipment manufacturers, it is our responsibility to rigorously inspect these linings before handing them over to our customers. This inspection should encompass both the quality of the Rubber Lining construction and the materials used because, at times, good construction practices can be just as critical as the materials themselves. DEF Rubber primarily focuses on providing high-quality rubber materials, but we also have valuable expertise in construction techniques. We are eager to share our insights and engage in technical discussions with those interested.

Quality standard for rubber lining:

After the construction of Rubber Linings within the equipment is completed, we must ensure that it meets our stringent quality standards consistently adhered to. These standards include:

1. Equipment designed with simplicity in mind: The metal shell structure housing the Rubber Lining should have a straightforward design to facilitate ease of operation during construction. This ensures that construction personnel and tools can easily access every corner to guarantee complete coverage.
2. Smooth and even metal shell surfaces: If sharp edges are necessary, they should feature rounded chamfers with internal radii greater than 5mm and external chamfer radii exceeding 3mm.
3. Avoidance of protruding structures: Any openings, interfaces, or similar structures within the rubber-lined equipment should not protrude beyond the inner surface of the device.
4. Preferred use of seamless steel pipes for rubber-lined pipelines: If cast iron pipes are used, their inner walls should be smooth, free from defects like sandholes, air holes, grooves, or burrs.
5. Inspection of shell pits: Surface imperfections like pits with a diameter larger than 3mm and depth exceeding 5mm should be welded and ground smooth. For pits with a diameter smaller than 3mm but a depth exceeding 5mm, grinding should precede welding. Pits with a diameter greater than 3mm and depth less than 5mm should also be ground smooth.
6. Examination of shell porosity: Generally, if there are pores with a diameter smaller than 3mm and depth exceeding 5mm, they should be ground and then welded and ground smooth.
7. Assessment of shell concave and convex corners: The shell should feature smooth rounded chamfers on both concave and convex corners, with a minimum radius of 5mm for concave corners and 3mm for convex corners.
8. Removal of weld slag: The shell’s surface should be smooth, with all weld slag and weld beads ground smooth.
9. Rubber Lining inspection: Check for bubbles, delamination, edge lifting, and surface depressions not exceeding 0.5mm in depth. Inspect for signs of abrasion, cracks, and sponge-like pores.
10. Size verification:Measurement of dimensions to confirm compliance with drawings.
11. Thickness measurement: Use a thickness gauge to check for areas where the Rubber Lining may have stretched during construction and ensure that critical areas meet the specified thickness after vulcanization.
12. Leak detection for insulated equipment: Employ an electric spark leak detector to assess the density of the Rubber Lining and ensure there are no electrical leaks.
13. Tap test: Gently tap the Rubber Lining to identify hollow spots, poor adhesion, or areas with incomplete bonding.
14. Rectifying identified defects: Defects must be repaired. New, unused equipment can be repaired using conventional methods. For previously used equipment, an analysis of the medium, operating temperature, and immersion duration is required. Repaired Rubber Linings should meet usage requirements.
15. Repair process: Begin by removing the rubber around the defect, creating a 30° bevel. For double-layer Rubber Linings, create a trapezoidal shape, exposing the metal shell, and clean the surface with solvent. Repair using the original rubber, perform localized vulcanization, and ensure the original rubber is not over-vulcanized. Depending on the conditions, pre-vulcanized rubber sheets or uncured rubber sheets (for room-temperature vulcanization) can also be used for natural curing. Alternatively, self-curing repair compounds like polymer alloy repair agents or synthetic resin putties can be employed. The commonly used method is fiberglass-reinforced plastic repair. In all cases, consider the bonding properties between materials, coefficient of expansion, and the effects of the medium to ensure that repaired areas seamlessly integrate with the overall lining, preventing localized defects from impacting the Rubber Lining’s service life.

In summary, Rubber Linings are essential for wear and corrosion resistance, offering numerous advantages. However, they can be susceptible to damage from hard objects, and equipment with Rubber Linings cannot undergo welding or be used for heat transfer purposes. We believe that as technology advances, there will be continuous development of improved Rubber Lining products. DEF Rubber is committed to exploring innovation and developing new rubber varieties in partnership with our customers. It represents the future—a high-tech, environmentally friendly product.